Replace the inhouse collection dependency resolver with resolvelib

PR #72591

This change:

  * Adds an artifacts manager that abstracts away extracting the
    metadata from artifacts, downloading and caching them in a
    temporary location.

  * Adds `resolvelib` to direct ansible-core dependencies[0].

  * Implements a `resolvelib`-based dependency resolver for
    `collection` subcommands that replaces the legacy
    in-house code.

    This is a dependency resolution library that pip 20.3+ uses
    by default. It's now integrated for use for the collection
    dependency resolution in ansible-galaxy CLI.

  * Refactors of the `ansible-galaxy collection` CLI.
    In particular, it:

      - reimplements most of the `download`, `install`, `list` and
        `verify` subcommands from scratch;

      - reuses helper bits previously moved out into external modules;

      - replaces the old in-house resolver with a more clear
        implementation based on the resolvelib library[0][1][2].

  * Adds a multi Galaxy API proxy layer that abstracts accessing the
    version and dependencies via API or local artifacts manager.

  * Makes `GalaxyAPI` instances sortable.

  * Adds string representation methods to `GalaxyAPI`.

  * Adds dev representation to `GalaxyAPI`.

  * Removes unnecessary integration and unit tests.

  * Aligns the tests with the new expectations.

  * Adds more tests, integration ones in particular.

[0]: https://pypi.org/p/resolvelib
[1]: https://github.com/sarugaku/resolvelib
[2]: https://pradyunsg.me/blog/2020/03/27/pip-resolver-testing

Co-Authored-By: Jordan Borean <jborean93@gmail.com>
Co-Authored-By: Matt Clay <matt@mystile.com>
Co-Authored-By: Sam Doran <sdoran@redhat.com>
Co-Authored-By: Sloane Hertel <shertel@redhat.com>
Co-Authored-By: Sviatoslav Sydorenko <webknjaz@redhat.com>

Signed-Off-By: Sviatoslav Sydorenko <webknjaz@redhat.com>

changelogs/fragments/72591-ansible-galaxy-collection-resolvelib.yaml

@@ -0,0 +1,27 @@
+---
+breaking_changes:
+- >-
+  Replaced the in-tree dependency resolver with an external implementation
+  that pip >= 20.3 uses now by default — ``resolvelib``.
+  (https://github.com/ansible/ansible/issues/71784)
+- >-
+  Made SCM collections be reinstalled regardless of ``--force`` being
+  present.
+major_changes:
+- |
+  Declared ``resolvelib >= 0.5.3, < 0.6.0`` a direct dependency of
+  ansible-core. Refs:
+  - https://github.com/sarugaku/resolvelib
+  - https://pypi.org/p/resolvelib
+  - https://pradyunsg.me/blog/2020/03/27/pip-resolver-testing
+- >-
+  It became possible to install Ansible Collections from local folders and
+  namespaces folder similar to SCM structure with multiple collections.
+minor_changes:
+- >-
+  Refactored ``ansible-galaxy collection [download|install|list|verify]``
+  CLI subcommands with the public interface kept intact.
+- >-
+  The new dependency resolver prefers ``MANIFEST.json`` over ``galaxy.yml``
+  if it exists in the target directory.
+...

lib/ansible/cli/galaxy.py

@@ -1,5 +1,5 @@
 # Copyright: (c) 2013, James Cammarata <jcammarata@ansible.com>
-# Copyright: (c) 2018, Ansible Project
+# Copyright: (c) 2018-2021, Ansible Project
 # GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
 
 from __future__ import (absolute_import, division, print_function)
@@ -24,7 +24,6 @@ from ansible.galaxy import Galaxy, get_collections_galaxy_meta_info
 from ansible.galaxy.api import GalaxyAPI
 from ansible.galaxy.collection import (
     build_collection,
-    CollectionRequirement,
     download_collections,
     find_existing_collections,
     install_collections,
@@ -33,6 +32,10 @@ from ansible.galaxy.collection import (
     validate_collection_path,
     verify_collections
 )
+from ansible.galaxy.collection.concrete_artifact_manager import (
+    ConcreteArtifactsManager,
+)
+from ansible.galaxy.dependency_resolution.dataclasses import Requirement
 
 from ansible.galaxy.role import GalaxyRole
 from ansible.galaxy.token import BasicAuthToken, GalaxyToken, KeycloakToken, NoTokenSentinel
@@ -52,6 +55,26 @@ display = Display()
 urlparse = six.moves.urllib.parse.urlparse
 
 
+def with_collection_artifacts_manager(wrapped_method):
+    """Inject an artifacts manager if not passed explicitly.
+
+    This decorator constructs a ConcreteArtifactsManager and maintains
+    the related temporary directory auto-cleanup around the target
+    method invocation.
+    """
+    def method_wrapper(*args, **kwargs):
+        if 'artifacts_manager' in kwargs:
+            return wrapped_method(*args, **kwargs)
+
+        with ConcreteArtifactsManager.under_tmpdir(
+                C.DEFAULT_LOCAL_TMP,
+                validate_certs=not context.CLIARGS['ignore_certs'],
+        ) as concrete_artifact_cm:
+            kwargs['artifacts_manager'] = concrete_artifact_cm
+            return wrapped_method(*args, **kwargs)
+    return method_wrapper
+
+
 def _display_header(path, h1, h2, w1=10, w2=7):
     display.display('\n# {0}\n{1:{cwidth}} {2:{vwidth}}\n{3} {4}\n'.format(
         path,
@@ -76,20 +99,19 @@ def _display_role(gr):
 
 def _display_collection(collection, cwidth=10, vwidth=7, min_cwidth=10, min_vwidth=7):
     display.display('{fqcn:{cwidth}} {version:{vwidth}}'.format(
-        fqcn=to_text(collection),
+        fqcn=to_text(collection.fqcn),
-        version=collection.latest_version,
+        version=collection.ver,
         cwidth=max(cwidth, min_cwidth),  # Make sure the width isn't smaller than the header
         vwidth=max(vwidth, min_vwidth)
     ))
 
 
 def _get_collection_widths(collections):
-    if is_iterable(collections):
+    if not is_iterable(collections):
-        fqcn_set = set(to_text(c) for c in collections)
+        collections = (collections, )
-        version_set = set(to_text(c.latest_version) for c in collections)
+
-    else:
+    fqcn_set = {to_text(c.fqcn) for c in collections}
-        fqcn_set = set([to_text(collections)])
+    version_set = {to_text(c.ver) for c in collections}
-        version_set = set([collections.latest_version])
 
     fqcn_length = len(max(fqcn_set, key=len))
     version_length = len(max(version_set, key=len))
@@ -447,7 +469,7 @@ class GalaxyCLI(CLI):
 
         # Need to filter out empty strings or non truthy values as an empty server list env var is equal to [''].
         server_list = [s for s in C.GALAXY_SERVER_LIST or [] if s]
-        for server_key in server_list:
+        for server_priority, server_key in enumerate(server_list, start=1):
             # Config definitions are looked up dynamically based on the C.GALAXY_SERVER_LIST entry. We look up the
             # section [galaxy_server.<server>] for the values url, username, password, and token.
             config_dict = dict((k, server_config_def(server_key, k, req)) for k, req in server_def)
@@ -486,7 +508,11 @@ class GalaxyCLI(CLI):
                         server_options['token'] = GalaxyToken(token=token_val)
 
             server_options.update(galaxy_options)
-            config_servers.append(GalaxyAPI(self.galaxy, server_key, **server_options))
+            config_servers.append(GalaxyAPI(
+                self.galaxy, server_key,
+                priority=server_priority,
+                **server_options
+            ))
 
         cmd_server = context.CLIARGS['api_server']
         cmd_token = GalaxyToken(token=context.CLIARGS['api_key'])
@@ -497,15 +523,21 @@ class GalaxyCLI(CLI):
             if config_server:
                 self.api_servers.append(config_server)
             else:
-                self.api_servers.append(GalaxyAPI(self.galaxy, 'cmd_arg', cmd_server, token=cmd_token,
+                self.api_servers.append(GalaxyAPI(
-                                                  **galaxy_options))
+                    self.galaxy, 'cmd_arg', cmd_server, token=cmd_token,
+                    priority=len(config_servers) + 1,
+                    **galaxy_options
+                ))
         else:
             self.api_servers = config_servers
 
         # Default to C.GALAXY_SERVER if no servers were defined
         if len(self.api_servers) == 0:
-            self.api_servers.append(GalaxyAPI(self.galaxy, 'default', C.GALAXY_SERVER, token=cmd_token,
+            self.api_servers.append(GalaxyAPI(
-                                              **galaxy_options))
+                self.galaxy, 'default', C.GALAXY_SERVER, token=cmd_token,
+                priority=0,
+                **galaxy_options
+            ))
 
         context.CLIARGS['func']()
 
@@ -530,7 +562,7 @@ class GalaxyCLI(CLI):
     def _get_default_collection_path(self):
         return C.COLLECTIONS_PATHS[0]
 
-    def _parse_requirements_file(self, requirements_file, allow_old_format=True):
+    def _parse_requirements_file(self, requirements_file, allow_old_format=True, artifacts_manager=None):
         """
         Parses an Ansible requirement.yml file and returns all the roles and/or collections defined in it. There are 2
         requirements file format:
@@ -556,6 +588,7 @@ class GalaxyCLI(CLI):
 
         :param requirements_file: The path to the requirements file.
         :param allow_old_format: Will fail if a v1 requirements file is found and this is set to False.
+        :param artifacts_manager: Artifacts manager.
         :return: a dict containing roles and collections to found in the requirements file.
         """
         requirements = {
@@ -619,33 +652,48 @@ class GalaxyCLI(CLI):
             for role_req in file_requirements.get('roles') or []:
                 requirements['roles'] += parse_role_req(role_req)
 
-            for collection_req in file_requirements.get('collections') or []:
+            requirements['collections'] = [
-                if isinstance(collection_req, dict):
+                Requirement.from_requirement_dict(
-                    req_name = collection_req.get('name', None)
+                    self._init_coll_req_dict(collection_req),
-                    if req_name is None:
+                    artifacts_manager,
-                        raise AnsibleError("Collections requirement entry should contain the key name.")
+                )
-
+                for collection_req in file_requirements.get('collections') or []
-                    req_type = collection_req.get('type')
+            ]
-                    if req_type not in ('file', 'galaxy', 'git', 'url', None):
-                        raise AnsibleError("The collection requirement entry key 'type' must be one of file, galaxy, git, or url.")
-
-                    req_version = collection_req.get('version', '*')
-                    req_source = collection_req.get('source', None)
-                    if req_source:
-                        # Try and match up the requirement source with our list of Galaxy API servers defined in the
-                        # config, otherwise create a server with that URL without any auth.
-                        req_source = next(iter([a for a in self.api_servers if req_source in [a.name, a.api_server]]),
-                                          GalaxyAPI(self.galaxy,
-                                                    "explicit_requirement_%s" % req_name,
-                                                    req_source,
-                                                    validate_certs=not context.CLIARGS['ignore_certs']))
-
-                    requirements['collections'].append((req_name, req_version, req_source, req_type))
-                else:
-                    requirements['collections'].append((collection_req, '*', None, None))
 
         return requirements
 
+    def _init_coll_req_dict(self, coll_req):
+        if not isinstance(coll_req, dict):
+            # Assume it's a string:
+            return {'name': coll_req}
+
+        if (
+                'name' not in coll_req or
+                not coll_req.get('source') or
+                coll_req.get('type', 'galaxy') != 'galaxy'
+        ):
+            return coll_req
+
+        # Try and match up the requirement source with our list of Galaxy API
+        # servers defined in the config, otherwise create a server with that
+        # URL without any auth.
+        coll_req['source'] = next(
+            iter(
+                srvr for srvr in self.api_servers
+                if coll_req['source'] in {srvr.name, srvr.api_server}
+            ),
+            GalaxyAPI(
+                self.galaxy,
+                'explicit_requirement_{name!s}'.format(
+                    name=coll_req['name'],
+                ),
+                coll_req['source'],
+                validate_certs=not context.CLIARGS['ignore_certs'],
+            ),
+        )
+
+        return coll_req
+
     @staticmethod
     def exit_without_ignore(rc=1):
         """
@@ -733,26 +781,29 @@ class GalaxyCLI(CLI):
 
         return meta_value
 
-    def _require_one_of_collections_requirements(self, collections, requirements_file):
+    def _require_one_of_collections_requirements(
+            self, collections, requirements_file,
+            artifacts_manager=None,
+    ):
         if collections and requirements_file:
             raise AnsibleError("The positional collection_name arg and --requirements-file are mutually exclusive.")
         elif not collections and not requirements_file:
             raise AnsibleError("You must specify a collection name or a requirements file.")
         elif requirements_file:
             requirements_file = GalaxyCLI._resolve_path(requirements_file)
-            requirements = self._parse_requirements_file(requirements_file, allow_old_format=False)
+            requirements = self._parse_requirements_file(
+                requirements_file,
+                allow_old_format=False,
+                artifacts_manager=artifacts_manager,
+            )
         else:
-            requirements = {'collections': [], 'roles': []}
+            requirements = {
-            for collection_input in collections:
+                'collections': [
-                requirement = None
+                    Requirement.from_string(coll_input, artifacts_manager)
-                if os.path.isfile(to_bytes(collection_input, errors='surrogate_or_strict')) or \
+                    for coll_input in collections
-                        urlparse(collection_input).scheme.lower() in ['http', 'https'] or \
+                ],
-                        collection_input.startswith(('git+', 'git@')):
+                'roles': [],
-                    # Arg is a file path or URL to a collection
+            }
-                    name = collection_input
-                else:
-                    name, dummy, requirement = collection_input.partition(':')
-                requirements['collections'].append((name, requirement or '*', None, None))
         return requirements
 
     ############################
@@ -792,27 +843,37 @@ class GalaxyCLI(CLI):
 
         for collection_path in context.CLIARGS['args']:
             collection_path = GalaxyCLI._resolve_path(collection_path)
-            build_collection(collection_path, output_path, force)
+            build_collection(
+                to_text(collection_path, errors='surrogate_or_strict'),
+                to_text(output_path, errors='surrogate_or_strict'),
+                force,
+            )
 
-    def execute_download(self):
+    @with_collection_artifacts_manager
+    def execute_download(self, artifacts_manager=None):
         collections = context.CLIARGS['args']
         no_deps = context.CLIARGS['no_deps']
         download_path = context.CLIARGS['download_path']
-        ignore_certs = context.CLIARGS['ignore_certs']
 
         requirements_file = context.CLIARGS['requirements']
         if requirements_file:
             requirements_file = GalaxyCLI._resolve_path(requirements_file)
 
-        requirements = self._require_one_of_collections_requirements(collections, requirements_file)['collections']
+        requirements = self._require_one_of_collections_requirements(
+            collections, requirements_file,
+            artifacts_manager=artifacts_manager,
+        )['collections']
 
         download_path = GalaxyCLI._resolve_path(download_path)
         b_download_path = to_bytes(download_path, errors='surrogate_or_strict')
         if not os.path.exists(b_download_path):
             os.makedirs(b_download_path)
 
-        download_collections(requirements, download_path, self.api_servers, (not ignore_certs), no_deps,
+        download_collections(
-                             context.CLIARGS['allow_pre_release'])
+            requirements, download_path, self.api_servers, no_deps,
+            context.CLIARGS['allow_pre_release'],
+            artifacts_manager=artifacts_manager,
+        )
 
         return 0
 
@@ -1002,29 +1063,38 @@ class GalaxyCLI(CLI):
 
         self.pager(data)
 
-    def execute_verify(self):
+    @with_collection_artifacts_manager
+    def execute_verify(self, artifacts_manager=None):
 
         collections = context.CLIARGS['args']
         search_paths = context.CLIARGS['collections_path']
-        ignore_certs = context.CLIARGS['ignore_certs']
         ignore_errors = context.CLIARGS['ignore_errors']
         requirements_file = context.CLIARGS['requirements']
 
-        requirements = self._require_one_of_collections_requirements(collections, requirements_file)['collections']
+        requirements = self._require_one_of_collections_requirements(
+            collections, requirements_file,
+            artifacts_manager=artifacts_manager,
+        )['collections']
 
         resolved_paths = [validate_collection_path(GalaxyCLI._resolve_path(path)) for path in search_paths]
 
-        verify_collections(requirements, resolved_paths, self.api_servers, (not ignore_certs), ignore_errors,
+        verify_collections(
-                           allow_pre_release=True)
+            requirements, resolved_paths,
+            self.api_servers, ignore_errors,
+            artifacts_manager=artifacts_manager,
+        )
 
         return 0
 
-    def execute_install(self):
+    @with_collection_artifacts_manager
+    def execute_install(self, artifacts_manager=None):
         """
         Install one or more roles(``ansible-galaxy role install``), or one or more collections(``ansible-galaxy collection install``).
         You can pass in a list (roles or collections) or use the file
         option listed below (these are mutually exclusive). If you pass in a list, it
         can be a name (which will be downloaded via the galaxy API and github), or it can be a local tar archive file.
+
+        :param artifacts_manager: Artifacts manager.
         """
         install_items = context.CLIARGS['args']
         requirements_file = context.CLIARGS['requirements']
@@ -1042,7 +1112,10 @@ class GalaxyCLI(CLI):
         role_requirements = []
         if context.CLIARGS['type'] == 'collection':
             collection_path = GalaxyCLI._resolve_path(context.CLIARGS['collections_path'])
-            requirements = self._require_one_of_collections_requirements(install_items, requirements_file)
+            requirements = self._require_one_of_collections_requirements(
+                install_items, requirements_file,
+                artifacts_manager=artifacts_manager,
+            )
 
             collection_requirements = requirements['collections']
             if requirements['roles']:
@@ -1055,7 +1128,10 @@ class GalaxyCLI(CLI):
                 if not (requirements_file.endswith('.yaml') or requirements_file.endswith('.yml')):
                     raise AnsibleError("Invalid role requirements file, it must end with a .yml or .yaml extension")
 
-                requirements = self._parse_requirements_file(requirements_file)
+                requirements = self._parse_requirements_file(
+                    requirements_file,
+                    artifacts_manager=artifacts_manager,
+                )
                 role_requirements = requirements['roles']
 
                 # We can only install collections and roles at the same time if the type wasn't specified and the -p
@@ -1090,11 +1166,15 @@ class GalaxyCLI(CLI):
             display.display("Starting galaxy collection install process")
             # Collections can technically be installed even when ansible-galaxy is in role mode so we need to pass in
             # the install path as context.CLIARGS['collections_path'] won't be set (default is calculated above).
-            self._execute_install_collection(collection_requirements, collection_path)
+            self._execute_install_collection(
+                collection_requirements, collection_path,
+                artifacts_manager=artifacts_manager,
+            )
 
-    def _execute_install_collection(self, requirements, path):
+    def _execute_install_collection(
+            self, requirements, path, artifacts_manager,
+    ):
         force = context.CLIARGS['force']
-        ignore_certs = context.CLIARGS['ignore_certs']
         ignore_errors = context.CLIARGS['ignore_errors']
         no_deps = context.CLIARGS['no_deps']
         force_with_deps = context.CLIARGS['force_with_deps']
@@ -1111,8 +1191,12 @@ class GalaxyCLI(CLI):
         if not os.path.exists(b_output_path):
             os.makedirs(b_output_path)
 
-        install_collections(requirements, output_path, self.api_servers, (not ignore_certs), ignore_errors,
+        install_collections(
-                            no_deps, force, force_with_deps, allow_pre_release=allow_pre_release)
+            requirements, output_path, self.api_servers, ignore_errors,
+            no_deps, force, force_with_deps,
+            allow_pre_release=allow_pre_release,
+            artifacts_manager=artifacts_manager,
+        )
 
         return 0
 
@@ -1283,9 +1367,12 @@ class GalaxyCLI(CLI):
 
         return 0
 
-    def execute_list_collection(self):
+    @with_collection_artifacts_manager
+    def execute_list_collection(self, artifacts_manager=None):
         """
         List all collections installed on the local system
+
+        :param artifacts_manager: Artifacts manager.
         """
 
         collections_search_paths = set(context.CLIARGS['collections_path'])
@@ -1328,8 +1415,16 @@ class GalaxyCLI(CLI):
                     continue
 
                 collection_found = True
-                collection = CollectionRequirement.from_path(b_collection_path, False, fallback_metadata=True)
+
-                fqcn_width, version_width = _get_collection_widths(collection)
+                try:
+                    collection = Requirement.from_dir_path_as_unknown(
+                        b_collection_path,
+                        artifacts_manager,
+                    )
+                except ValueError as val_err:
+                    six.raise_from(AnsibleError(val_err), val_err)
+
+                fqcn_width, version_width = _get_collection_widths([collection])
 
                 _display_header(collection_path, 'Collection', 'Version', fqcn_width, version_width)
                 _display_collection(collection, fqcn_width, version_width)
@@ -1339,7 +1434,9 @@ class GalaxyCLI(CLI):
                 collection_path = validate_collection_path(path)
                 if os.path.isdir(collection_path):
                     display.vvv("Searching {0} for collections".format(collection_path))
-                    collections = find_existing_collections(collection_path, fallback_metadata=True)
+                    collections = list(find_existing_collections(
+                        collection_path, artifacts_manager,
+                    ))
                 else:
                     # There was no 'ansible_collections/' directory in the path, so there
                     # or no collections here.
@@ -1355,8 +1452,7 @@ class GalaxyCLI(CLI):
                 _display_header(collection_path, 'Collection', 'Version', fqcn_width, version_width)
 
                 # Sort collections by the namespace and name
-                collections.sort(key=to_text)
+                for collection in sorted(collections, key=to_text):
-                for collection in collections:
                     _display_collection(collection, fqcn_width, version_width)
 
         # Do not warn if the specific collection was found in any of the search paths

lib/ansible/galaxy/api.py

@@ -7,6 +7,7 @@ __metaclass__ = type
 
 import collections
 import datetime
+import functools
 import hashlib
 import json
 import os
@@ -233,11 +234,17 @@ class CollectionVersionMetadata:
         self.dependencies = dependencies
 
 
+@functools.total_ordering
 class GalaxyAPI:
     """ This class is meant to be used as a API client for an Ansible Galaxy server """
 
-    def __init__(self, galaxy, name, url, username=None, password=None, token=None, validate_certs=True,
+    def __init__(
-                 available_api_versions=None, clear_response_cache=False, no_cache=True):
+            self, galaxy, name, url,
+            username=None, password=None, token=None, validate_certs=True,
+            available_api_versions=None,
+            clear_response_cache=False, no_cache=True,
+            priority=float('inf'),
+    ):
         self.galaxy = galaxy
         self.name = name
         self.username = username
@@ -246,6 +253,7 @@ class GalaxyAPI:
         self.api_server = url
         self.validate_certs = validate_certs
         self._available_api_versions = available_api_versions or {}
+        self._priority = priority
 
         b_cache_dir = to_bytes(C.config.get_config_value('GALAXY_CACHE_DIR'), errors='surrogate_or_strict')
         makedirs_safe(b_cache_dir, mode=0o700)
@@ -263,6 +271,38 @@ class GalaxyAPI:
 
         display.debug('Validate TLS certificates for %s: %s' % (self.api_server, self.validate_certs))
 
+    def __str__(self):
+        # type: (GalaxyAPI) -> str
+        """Render GalaxyAPI as a native string representation."""
+        return to_native(self.name)
+
+    def __unicode__(self):
+        # type: (GalaxyAPI) -> unicode
+        """Render GalaxyAPI as a unicode/text string representation."""
+        return to_text(self.name)
+
+    def __repr__(self):
+        # type: (GalaxyAPI) -> str
+        """Render GalaxyAPI as an inspectable string representation."""
+        return (
+            '<{instance!s} "{name!s}" @ {url!s} with priority {priority!s}>'.
+            format(
+                instance=self, name=self.name,
+                priority=self._priority, url=self.api_server,
+            )
+        )
+
+    def __lt__(self, other_galaxy_api):
+        # type: (GalaxyAPI, GalaxyAPI) -> Union[bool, 'NotImplemented']
+        """Return whether the instance priority is higher than other."""
+        if not isinstance(other_galaxy_api, self.__class__):
+            return NotImplemented
+
+        return (
+            self._priority > other_galaxy_api._priority or
+            self.name < self.name
+        )
+
     @property
     @g_connect(['v1', 'v2', 'v3'])
     def available_api_versions(self):

lib/ansible/galaxy/collection/concrete_artifact_manager.py

@@ -0,0 +1,646 @@
+# -*- coding: utf-8 -*-
+# Copyright: (c) 2020-2021, Ansible Project
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+"""Concrete collection candidate management helper module."""
+
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+import json
+import os
+import tarfile
+import subprocess
+from contextlib import contextmanager
+from hashlib import sha256
+from shutil import rmtree
+from tempfile import mkdtemp
+
+try:
+    from typing import TYPE_CHECKING
+except ImportError:
+    TYPE_CHECKING = False
+
+if TYPE_CHECKING:
+    from typing import (
+        Any,  # FIXME: !!!111
+        BinaryIO, Dict, IO,
+        Iterator, List, Optional,
+        Set, Tuple, Type, Union,
+    )
+
+    from ansible.galaxy.dependency_resolution.dataclasses import (
+        Candidate, Requirement,
+    )
+    from ansible.galaxy.token import GalaxyToken
+
+from ansible.errors import AnsibleError
+from ansible.galaxy import get_collections_galaxy_meta_info
+from ansible.galaxy.dependency_resolution.dataclasses import _GALAXY_YAML
+from ansible.galaxy.user_agent import user_agent
+from ansible.module_utils._text import to_bytes, to_native, to_text
+from ansible.module_utils.six.moves.urllib.error import URLError
+from ansible.module_utils.six.moves.urllib.parse import urldefrag
+from ansible.module_utils.six import raise_from
+from ansible.module_utils.urls import open_url
+from ansible.utils.display import Display
+
+import yaml
+
+
+display = Display()
+
+
+class ConcreteArtifactsManager:
+    """Manager for on-disk collection artifacts.
+
+    It is responsible for:
+        * downloading remote collections from Galaxy-compatible servers and
+          direct links to tarballs or SCM repositories
+        * keeping track of local ones
+        * keeping track of Galaxy API tokens for downloads from Galaxy'ish
+          as well as the artifact hashes
+        * caching all of above
+        * retrieving the metadata out of the downloaded artifacts
+    """
+
+    def __init__(self, b_working_directory, validate_certs=True):
+        # type: (bytes, bool) -> None
+        """Initialize ConcreteArtifactsManager caches and costraints."""
+        self._validate_certs = validate_certs  # type: bool
+        self._artifact_cache = {}  # type: Dict[bytes, bytes]
+        self._galaxy_artifact_cache = {}  # type: Dict[Union[Candidate, Requirement], bytes]
+        self._artifact_meta_cache = {}  # type: Dict[bytes, Dict[str, Optional[Union[str, List[str], Dict[str, str]]]]]
+        self._galaxy_collection_cache = {}  # type: Dict[Union[Candidate, Requirement], Tuple[str, str, GalaxyToken]]
+        self._b_working_directory = b_working_directory  # type: bytes
+
+    def get_galaxy_artifact_path(self, collection):
+        # type: (Union[Candidate, Requirement]) -> bytes
+        """Given a Galaxy-stored collection, return a cached path.
+
+        If it's not yet on disk, this method downloads the artifact first.
+        """
+        try:
+            return self._galaxy_artifact_cache[collection]
+        except KeyError:
+            pass
+
+        try:
+            url, sha256_hash, token = self._galaxy_collection_cache[collection]
+        except KeyError as key_err:
+            raise_from(
+                RuntimeError(
+                    'The is no known source for {coll!s}'.
+                    format(coll=collection),
+                ),
+                key_err,
+            )
+
+        display.vvvv(
+            "Fetching a collection tarball for '{collection!s}' from "
+            'Ansible Galaxy'.format(collection=collection),
+        )
+
+        try:
+            b_artifact_path = _download_file(
+                url,
+                self._b_working_directory,
+                expected_hash=sha256_hash,
+                validate_certs=self._validate_certs,
+                token=token,
+            )  # type: bytes
+        except URLError as err:
+            raise_from(
+                AnsibleError(
+                    'Failed to download collection tar '
+                    "from '{coll_src!s}': {download_err!s}".
+                    format(
+                        coll_src=to_native(collection.src),
+                        download_err=to_native(err),
+                    ),
+                ),
+                err,
+            )
+        else:
+            display.vvv(
+                "Collection '{coll!s}' obtained from "
+                'server {server!s} {url!s}'.format(
+                    coll=collection, server=collection.src or 'Galaxy',
+                    url=collection.src.api_server if collection.src is not None
+                    else '',
+                )
+            )
+
+        self._galaxy_artifact_cache[collection] = b_artifact_path
+        return b_artifact_path
+
+    def get_artifact_path(self, collection):
+        # type: (Union[Candidate, Requirement]) -> bytes
+        """Given a concrete collection pointer, return a cached path.
+
+        If it's not yet on disk, this method downloads the artifact first.
+        """
+        try:
+            return self._artifact_cache[collection.src]
+        except KeyError:
+            pass
+
+        # NOTE: SCM needs to be special-cased as it may contain either
+        # NOTE: one collection in its root, or a number of top-level
+        # NOTE: collection directories instead.
+        # NOTE: The idea is to store the SCM collection as unpacked
+        # NOTE: directory structure under the temporary location and use
+        # NOTE: a "virtual" collection that has pinned requirements on
+        # NOTE: the directories under that SCM checkout that correspond
+        # NOTE: to collections.
+        # NOTE: This brings us to the idea that we need two separate
+        # NOTE: virtual Requirement/Candidate types --
+        # NOTE: (single) dir + (multidir) subdirs
+        if collection.is_url:
+            display.vvvv(
+                "Collection requirement '{collection!s}' is a URL "
+                'to a tar artifact'.format(collection=collection.fqcn),
+            )
+            try:
+                b_artifact_path = _download_file(
+                    collection.src,
+                    self._b_working_directory,
+                    expected_hash=None,  # NOTE: URLs don't support checksums
+                    validate_certs=self._validate_certs,
+                )
+            except URLError as err:
+                raise_from(
+                    AnsibleError(
+                        'Failed to download collection tar '
+                        "from '{coll_src!s}': {download_err!s}".
+                        format(
+                            coll_src=to_native(collection.src),
+                            download_err=to_native(err),
+                        ),
+                    ),
+                    err,
+                )
+        elif collection.is_scm:
+            b_artifact_path = _extract_collection_from_git(
+                collection.src,
+                collection.ver,
+                self._b_working_directory,
+            )
+        elif collection.is_file or collection.is_dir or collection.is_subdirs:
+            b_artifact_path = to_bytes(collection.src)
+        else:
+            # NOTE: This may happen `if collection.is_online_index_pointer`
+            raise RuntimeError(
+                'The artifact is of an unexpected type {art_type!s}'.
+                format(art_type=collection.type)
+            )
+
+        self._artifact_cache[collection.src] = b_artifact_path
+        return b_artifact_path
+
+    def _get_direct_collection_namespace(self, collection):
+        # type: (Candidate) -> Optional[str]
+        return self.get_direct_collection_meta(collection)['namespace']  # type: ignore[return-value]
+
+    def _get_direct_collection_name(self, collection):
+        # type: (Candidate) -> Optional[str]
+        return self.get_direct_collection_meta(collection)['name']  # type: ignore[return-value]
+
+    def get_direct_collection_fqcn(self, collection):
+        # type: (Candidate) -> Optional[str]
+        """Extract FQCN from the given on-disk collection artifact.
+
+        If the collection is virtual, ``None`` is returned instead
+        of a string.
+        """
+        if collection.is_virtual:
+            # NOTE: should it be something like "<virtual>"?
+            return None
+
+        return '.'.join((  # type: ignore[type-var]
+            self._get_direct_collection_namespace(collection),  # type: ignore[arg-type]
+            self._get_direct_collection_name(collection),
+        ))
+
+    def get_direct_collection_version(self, collection):
+        # type: (Union[Candidate, Requirement]) -> str
+        """Extract version from the given on-disk collection artifact."""
+        return self.get_direct_collection_meta(collection)['version']  # type: ignore[return-value]
+
+    def get_direct_collection_dependencies(self, collection):
+        # type: (Union[Candidate, Requirement]) -> Dict[str, str]
+        """Extract deps from the given on-disk collection artifact."""
+        return self.get_direct_collection_meta(collection)['dependencies']  # type: ignore[return-value]
+
+    def get_direct_collection_meta(self, collection):
+        # type: (Union[Candidate, Requirement]) -> Dict[str, Optional[Union[str, Dict[str, str], List[str]]]]
+        """Extract meta from the given on-disk collection artifact."""
+        try:  # FIXME: use unique collection identifier as a cache key?
+            return self._artifact_meta_cache[collection.src]
+        except KeyError:
+            b_artifact_path = self.get_artifact_path(collection)
+
+        if collection.is_url or collection.is_file:
+            collection_meta = _get_meta_from_tar(b_artifact_path)
+        elif collection.is_dir:  # should we just build a coll instead?
+            # FIXME: what if there's subdirs?
+            try:
+                collection_meta = _get_meta_from_dir(b_artifact_path)
+            except LookupError as lookup_err:
+                raise_from(
+                    AnsibleError(
+                        'Failed to find the collection dir deps: {err!s}'.
+                        format(err=to_native(lookup_err)),
+                    ),
+                    lookup_err,
+                )
+        elif collection.is_scm:
+            collection_meta = {
+                'name': None,
+                'namespace': None,
+                'dependencies': {to_native(b_artifact_path): '*'},
+                'version': '*',
+            }
+        elif collection.is_subdirs:
+            collection_meta = {
+                'name': None,
+                'namespace': None,
+                # NOTE: Dropping b_artifact_path since it's based on src anyway
+                'dependencies': dict.fromkeys(
+                    map(to_native, collection.namespace_collection_paths),
+                    '*',
+                ),
+                'version': '*',
+            }
+        else:
+            raise RuntimeError
+
+        self._artifact_meta_cache[collection.src] = collection_meta
+        return collection_meta
+
+    def save_collection_source(self, collection, url, sha256_hash, token):
+        # type: (Candidate, str, str, GalaxyToken) -> None
+        """Store collection URL, SHA256 hash and Galaxy API token.
+
+        This is a hook that is supposed to be called before attempting to
+        download Galaxy-based collections with ``get_galaxy_artifact_path()``.
+        """
+        self._galaxy_collection_cache[collection] = url, sha256_hash, token
+
+    @classmethod
+    @contextmanager
+    def under_tmpdir(
+            cls,  # type: Type[ConcreteArtifactsManager]
+            temp_dir_base,  # type: str
+            validate_certs=True,  # type: bool
+    ):  # type: (...) -> Iterator[ConcreteArtifactsManager]
+        """Custom ConcreteArtifactsManager constructor with temp dir.
+
+        This method returns a context manager that allocates and cleans
+        up a temporary directory for caching the collection artifacts
+        during the dependency resolution process.
+        """
+        # NOTE: Can't use `with tempfile.TemporaryDirectory:`
+        # NOTE: because it's not in Python 2 stdlib.
+        temp_path = mkdtemp(
+            dir=to_bytes(temp_dir_base, errors='surrogate_or_strict'),
+        )
+        b_temp_path = to_bytes(temp_path, errors='surrogate_or_strict')
+        try:
+            yield cls(b_temp_path, validate_certs)
+        finally:
+            rmtree(b_temp_path)
+
+
+def parse_scm(collection, version):
+    """Extract name, version, path and subdir out of the SCM pointer."""
+    if ',' in collection:
+        collection, version = collection.split(',', 1)
+    elif version == '*' or not version:
+        version = 'HEAD'
+
+    if collection.startswith('git+'):
+        path = collection[4:]
+    else:
+        path = collection
+
+    path, fragment = urldefrag(path)
+    fragment = fragment.strip(os.path.sep)
+
+    if path.endswith(os.path.sep + '.git'):
+        name = path.split(os.path.sep)[-2]
+    elif '://' not in path and '@' not in path:
+        name = path
+    else:
+        name = path.split('/')[-1]
+        if name.endswith('.git'):
+            name = name[:-4]
+
+    return name, version, path, fragment
+
+
+def _extract_collection_from_git(repo_url, coll_ver, b_path):
+    name, version, git_url, fragment = parse_scm(repo_url, coll_ver)
+    b_checkout_path = mkdtemp(
+        dir=b_path,
+        prefix=to_bytes(name, errors='surrogate_or_strict'),
+    )  # type: bytes
+    git_clone_cmd = 'git', 'clone', git_url, to_text(b_checkout_path)
+    # FIXME: '--depth', '1', '--branch', version
+    try:
+        subprocess.check_call(git_clone_cmd)
+    except subprocess.CalledProcessError as proc_err:
+        raise_from(
+            AnsibleError(  # should probably be LookupError
+                'Failed to clone a Git repository from `{repo_url!s}`.'.
+                format(repo_url=to_native(git_url)),
+            ),
+            proc_err,
+        )
+
+    git_switch_cmd = 'git', 'checkout', to_text(version)
+    try:
+        subprocess.check_call(git_switch_cmd, cwd=b_checkout_path)
+    except subprocess.CalledProcessError as proc_err:
+        raise_from(
+            AnsibleError(  # should probably be LookupError
+                'Failed to switch a cloned Git repo `{repo_url!s}` '
+                'to the requested revision `{commitish!s}`.'.
+                format(
+                    commitish=to_native(version),
+                    repo_url=to_native(git_url),
+                ),
+            ),
+            proc_err,
+        )
+
+    return (
+        os.path.join(b_checkout_path, to_bytes(fragment))
+        if fragment else b_checkout_path
+    )
+
+
+# FIXME: use random subdirs while preserving the file names
+def _download_file(url, b_path, expected_hash, validate_certs, token=None):
+    # type: (str, bytes, Optional[str], bool, GalaxyToken) -> bytes
+    # ^ NOTE: used in download and verify_collections ^
+    b_tarball_name = to_bytes(
+        url.rsplit('/', 1)[1], errors='surrogate_or_strict',
+    )
+    b_file_name = b_tarball_name[:-len('.tar.gz')]
+
+    b_tarball_dir = mkdtemp(
+        dir=b_path,
+        prefix=b'-'.join((b_file_name, b'')),
+    )  # type: bytes
+
+    b_file_path = os.path.join(b_tarball_dir, b_tarball_name)
+
+    display.display("Downloading %s to %s" % (url, to_text(b_tarball_dir)))
+    # NOTE: Galaxy redirects downloads to S3 which rejects the request
+    # NOTE: if an Authorization header is attached so don't redirect it
+    resp = open_url(
+        to_native(url, errors='surrogate_or_strict'),
+        validate_certs=validate_certs,
+        headers=None if token is None else token.headers(),
+        unredirected_headers=['Authorization'], http_agent=user_agent(),
+    )
+
+    with open(b_file_path, 'wb') as download_file:  # type: BinaryIO
+        actual_hash = _consume_file(resp, write_to=download_file)
+
+    if expected_hash:
+        display.vvvv(
+            'Validating downloaded file hash {actual_hash!s} with '
+            'expected hash {expected_hash!s}'.
+            format(actual_hash=actual_hash, expected_hash=expected_hash)
+        )
+        if expected_hash != actual_hash:
+            raise AnsibleError('Mismatch artifact hash with downloaded file')
+
+    return b_file_path
+
+
+def _consume_file(read_from, write_to=None):
+    # type: (BinaryIO, BinaryIO) -> str
+    bufsize = 65536
+    sha256_digest = sha256()
+    data = read_from.read(bufsize)
+    while data:
+        if write_to is not None:
+            write_to.write(data)
+            write_to.flush()
+        sha256_digest.update(data)
+        data = read_from.read(bufsize)
+
+    return sha256_digest.hexdigest()
+
+
+def _normalize_galaxy_yml_manifest(
+        galaxy_yml,  # type: Dict[str, Optional[Union[str, List[str], Dict[str, str]]]]
+        b_galaxy_yml_path,  # type: bytes
+):
+    # type: (...) -> Dict[str, Optional[Union[str, List[str], Dict[str, str]]]]
+    galaxy_yml_schema = (
+        get_collections_galaxy_meta_info()
+    )  # type: List[Dict[str, Any]]  # FIXME: <--
+    # FIXME: 👆maybe precise type: List[Dict[str, Union[bool, str, List[str]]]]
+
+    mandatory_keys = set()
+    string_keys = set()  # type: Set[str]
+    list_keys = set()  # type: Set[str]
+    dict_keys = set()  # type: Set[str]
+
+    for info in galaxy_yml_schema:
+        if info.get('required', False):
+            mandatory_keys.add(info['key'])
+
+        key_list_type = {
+            'str': string_keys,
+            'list': list_keys,
+            'dict': dict_keys,
+        }[info.get('type', 'str')]
+        key_list_type.add(info['key'])
+
+    all_keys = frozenset(list(mandatory_keys) + list(string_keys) + list(list_keys) + list(dict_keys))
+
+    set_keys = set(galaxy_yml.keys())
+    missing_keys = mandatory_keys.difference(set_keys)
+    if missing_keys:
+        raise AnsibleError("The collection galaxy.yml at '%s' is missing the following mandatory keys: %s"
+                           % (to_native(b_galaxy_yml_path), ", ".join(sorted(missing_keys))))
+
+    extra_keys = set_keys.difference(all_keys)
+    if len(extra_keys) > 0:
+        display.warning("Found unknown keys in collection galaxy.yml at '%s': %s"
+                        % (to_text(b_galaxy_yml_path), ", ".join(extra_keys)))
+
+    # Add the defaults if they have not been set
+    for optional_string in string_keys:
+        if optional_string not in galaxy_yml:
+            galaxy_yml[optional_string] = None
+
+    for optional_list in list_keys:
+        list_val = galaxy_yml.get(optional_list, None)
+
+        if list_val is None:
+            galaxy_yml[optional_list] = []
+        elif not isinstance(list_val, list):
+            galaxy_yml[optional_list] = [list_val]  # type: ignore[list-item]
+
+    for optional_dict in dict_keys:
+        if optional_dict not in galaxy_yml:
+            galaxy_yml[optional_dict] = {}
+
+    # NOTE: `version: null` is only allowed for `galaxy.yml`
+    # NOTE: and not `MANIFEST.json`. The use-case for it is collections
+    # NOTE: that generate the version from Git before building a
+    # NOTE: distributable tarball artifact.
+    if not galaxy_yml.get('version'):
+        galaxy_yml['version'] = '*'
+
+    return galaxy_yml
+
+
+def _get_meta_from_dir(
+        b_path,  # type: bytes
+):  # type: (...) -> Dict[str, Optional[Union[str, List[str], Dict[str, str]]]]
+    try:
+        return _get_meta_from_installed_dir(b_path)
+    except LookupError:
+        return _get_meta_from_src_dir(b_path)
+
+
+def _get_meta_from_src_dir(
+        b_path,  # type: bytes
+):  # type: (...) -> Dict[str, Optional[Union[str, List[str], Dict[str, str]]]]
+    galaxy_yml = os.path.join(b_path, _GALAXY_YAML)
+    if not os.path.isfile(galaxy_yml):
+        raise LookupError(
+            "The collection galaxy.yml path '{path!s}' does not exist.".
+            format(path=to_native(galaxy_yml))
+        )
+
+    with open(galaxy_yml, 'rb') as manifest_file_obj:
+        try:
+            manifest = yaml.safe_load(manifest_file_obj)
+        except yaml.error.YAMLError as yaml_err:
+            raise_from(
+                AnsibleError(
+                    "Failed to parse the galaxy.yml at '{path!s}' with "
+                    'the following error:\n{err_txt!s}'.
+                    format(
+                        path=to_native(galaxy_yml),
+                        err_txt=to_native(yaml_err),
+                    ),
+                ),
+                yaml_err,
+            )
+
+    return _normalize_galaxy_yml_manifest(manifest, galaxy_yml)
+
+
+def _get_meta_from_installed_dir(
+        b_path,  # type: bytes
+):  # type: (...) -> Dict[str, Optional[Union[str, List[str], Dict[str, str]]]]
+    n_manifest_json = 'MANIFEST.json'
+    b_manifest_json = to_bytes(n_manifest_json)
+    b_manifest_json_path = os.path.join(b_path, b_manifest_json)
+
+    try:
+        with open(b_manifest_json_path, 'rb') as manifest_fd:
+            b_manifest_txt = manifest_fd.read()
+    except (IOError, OSError):
+        raise LookupError(
+            "The collection {manifest!s} path '{path!s}' does not exist.".
+            format(
+                manifest=n_manifest_json,
+                path=to_native(b_manifest_json_path),
+            )
+        )
+
+    manifest_txt = to_text(b_manifest_txt, errors='surrogate_or_strict')
+
+    try:
+        manifest = json.loads(manifest_txt)
+    except ValueError:
+        raise AnsibleError(
+            'Collection tar file member {member!s} does not '
+            'contain a valid json string.'.
+            format(member=n_manifest_json),
+        )
+    else:
+        collection_info = manifest['collection_info']
+
+    version = collection_info.get('version')
+    if not version:
+        raise AnsibleError(
+            u'Collection metadata file at `{meta_file!s}` is expected '
+            u'to have a valid SemVer version value but got {version!s}'.
+            format(
+                meta_file=to_text(b_manifest_json_path),
+                version=to_text(repr(version)),
+            ),
+        )
+
+    return collection_info
+
+
+def _get_meta_from_tar(
+        b_path,  # type: bytes
+):  # type: (...) -> Dict[str, Optional[Union[str, List[str], Dict[str, str]]]]
+    if not tarfile.is_tarfile(b_path):
+        raise AnsibleError(
+            "Collection artifact at '{path!s}' is not a valid tar file.".
+            format(path=to_native(b_path)),
+        )
+
+    n_manifest_json = 'MANIFEST.json'
+
+    with tarfile.open(b_path, mode='r') as collection_tar:  # type: tarfile.TarFile
+        try:
+            member = collection_tar.getmember(n_manifest_json)
+        except KeyError:
+            raise AnsibleError(
+                "Collection at '{path!s}' does not contain the "
+                'required file {manifest_file!s}.'.
+                format(
+                    path=to_native(b_path),
+                    manifest_file=n_manifest_json,
+                ),
+            )
+
+        with _tarfile_extract(collection_tar, member) as (_member, member_obj):
+            if member_obj is None:
+                raise AnsibleError(
+                    'Collection tar file does not contain '
+                    'member {member!s}'.format(member=n_manifest_json),
+                )
+
+            text_content = to_text(
+                member_obj.read(),
+                errors='surrogate_or_strict',
+            )
+
+            try:
+                manifest = json.loads(text_content)
+            except ValueError:
+                raise AnsibleError(
+                    'Collection tar file member {member!s} does not '
+                    'contain a valid json string.'.
+                    format(member=n_manifest_json),
+                )
+            return manifest['collection_info']
+
+
+@contextmanager
+def _tarfile_extract(
+        tar,  # type: tarfile.TarFile
+        member,  # type: tarfile.TarInfo
+):
+    # type: (...) -> Iterator[Tuple[tarfile.TarInfo, Optional[IO[bytes]]]]
+    tar_obj = tar.extractfile(member)
+    try:
+        yield member, tar_obj
+    finally:
+        if tar_obj is not None:
+            tar_obj.close()

lib/ansible/galaxy/collection/galaxy_api_proxy.py

@@ -0,0 +1,107 @@
+# -*- coding: utf-8 -*-
+# Copyright: (c) 2020-2021, Ansible Project
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+"""A facade for interfacing with multiple Galaxy instances."""
+
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+import os
+
+try:
+    from typing import TYPE_CHECKING
+except ImportError:
+    TYPE_CHECKING = False
+
+if TYPE_CHECKING:
+    from typing import Dict, Iterable, Tuple
+    from ansible.galaxy.api import CollectionVersionMetadata
+    from ansible.galaxy.collection.concrete_artifact_manager import (
+        ConcreteArtifactsManager,
+    )
+    from ansible.galaxy.dependency_resolution.dataclasses import (
+        Candidate, Requirement,
+    )
+
+from ansible.galaxy.api import GalaxyAPI, GalaxyError
+
+
+class MultiGalaxyAPIProxy:
+    """A proxy that abstracts talking to multiple Galaxy instances."""
+
+    def __init__(self, apis, concrete_artifacts_manager):
+        # type: (Iterable[GalaxyAPI], ConcreteArtifactsManager) -> None
+        """Initialize the target APIs list."""
+        self._apis = apis
+        self._concrete_art_mgr = concrete_artifacts_manager
+
+    def get_collection_versions(self, requirement):
+        # type: (Requirement) -> Iterable[Tuple[str, GalaxyAPI]]
+        """Get a set of unique versions for FQCN on Galaxy servers."""
+        if requirement.is_concrete_artifact:
+            return {
+                (
+                    self._concrete_art_mgr.
+                    get_direct_collection_version(requirement),
+                    requirement.src,
+                ),
+            }
+
+        api_lookup_order = (
+            (requirement.src, )
+            if isinstance(requirement.src, GalaxyAPI)
+            else self._apis
+        )
+        return set(
+            (version, api)
+            for api in api_lookup_order
+            for version in api.get_collection_versions(
+                requirement.namespace, requirement.name,
+            )
+        )
+
+    def get_collection_version_metadata(self, collection_candidate):
+        # type: (Candidate) -> CollectionVersionMetadata
+        """Retrieve collection metadata of a given candidate."""
+
+        api_lookup_order = (
+            (collection_candidate.src, )
+            if isinstance(collection_candidate.src, GalaxyAPI)
+            else self._apis
+        )
+        for api in api_lookup_order:
+            try:
+                version_metadata = api.get_collection_version_metadata(
+                    collection_candidate.namespace,
+                    collection_candidate.name,
+                    collection_candidate.ver,
+                )
+            except GalaxyError as api_err:
+                last_err = api_err
+            else:
+                self._concrete_art_mgr.save_collection_source(
+                    collection_candidate,
+                    version_metadata.download_url,
+                    version_metadata.artifact_sha256,
+                    api.token,
+                )
+                return version_metadata
+
+        raise last_err
+
+    def get_collection_dependencies(self, collection_candidate):
+        # type: (Candidate) -> Dict[str, str]
+        # FIXME: return Requirement instances instead?
+        """Retrieve collection dependencies of a given candidate."""
+        if collection_candidate.is_concrete_artifact:
+            return (
+                self.
+                _concrete_art_mgr.
+                get_direct_collection_dependencies
+            )(collection_candidate)
+
+        return (
+            self.
+            get_collection_version_metadata(collection_candidate).
+            dependencies
+        )

lib/ansible/galaxy/dependency_resolution/__init__.py

@@ -1,7 +1,49 @@
 # -*- coding: utf-8 -*-
-# Copyright: (c) 2020, Ansible Project
+# Copyright: (c) 2020-2021, Ansible Project
 # GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
 """Dependency resolution machinery."""
 
 from __future__ import (absolute_import, division, print_function)
 __metaclass__ = type
+
+try:
+    from typing import TYPE_CHECKING
+except ImportError:
+    TYPE_CHECKING = False
+
+if TYPE_CHECKING:
+    from typing import Iterable
+    from ansible.galaxy.api import GalaxyAPI
+    from ansible.galaxy.collection.concrete_artifact_manager import (
+        ConcreteArtifactsManager,
+    )
+    from ansible.galaxy.dependency_resolution.dataclasses import Candidate
+
+from ansible.galaxy.collection.galaxy_api_proxy import MultiGalaxyAPIProxy
+from ansible.galaxy.dependency_resolution.providers import CollectionDependencyProvider
+from ansible.galaxy.dependency_resolution.reporters import CollectionDependencyReporter
+from ansible.galaxy.dependency_resolution.resolvers import CollectionDependencyResolver
+
+
+def build_collection_dependency_resolver(
+        galaxy_apis,  # type: Iterable[GalaxyAPI]
+        concrete_artifacts_manager,  # type: ConcreteArtifactsManager
+        preferred_candidates=None,  # type: Iterable[Candidate]
+        with_deps=True,  # type: bool
+        with_pre_releases=False,  # type: bool
+):  # type: (...) -> CollectionDependencyResolver
+    """Return a collection dependency resolver.
+
+    The returned instance will have a ``resolve()`` method for
+    further consumption.
+    """
+    return CollectionDependencyResolver(
+        CollectionDependencyProvider(
+            apis=MultiGalaxyAPIProxy(galaxy_apis, concrete_artifacts_manager),
+            concrete_artifacts_manager=concrete_artifacts_manager,
+            preferred_candidates=preferred_candidates,
+            with_deps=with_deps,
+            with_pre_releases=with_pre_releases,
+        ),
+        CollectionDependencyReporter(),
+    )

lib/ansible/galaxy/dependency_resolution/dataclasses.py

@@ -0,0 +1,435 @@
+# -*- coding: utf-8 -*-
+# Copyright: (c) 2020-2021, Ansible Project
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+"""Dependency structs."""
+# FIXME: add caching all over the place
+
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+import json
+import os
+from collections import namedtuple
+from glob import iglob
+from keyword import iskeyword  # used in _is_fqcn
+
+try:
+    from typing import TYPE_CHECKING
+except ImportError:
+    TYPE_CHECKING = False
+
+if TYPE_CHECKING:
+    from typing import Tuple, Type, TypeVar
+    from ansible.galaxy.collection.concrete_artifact_manager import (
+        ConcreteArtifactsManager,
+    )
+    Collection = TypeVar(
+        'Collection',
+        'Candidate', 'Requirement',
+        '_ComputedReqKindsMixin',
+    )
+
+import yaml
+
+from ansible.errors import AnsibleError
+from ansible.galaxy.api import GalaxyAPI
+from ansible.module_utils._text import to_bytes, to_native, to_text
+from ansible.module_utils.six.moves.urllib.parse import urlparse
+from ansible.module_utils.six import raise_from
+from ansible.utils.display import Display
+
+
+try:  # NOTE: py3/py2 compat
+    # FIXME: put somewhere into compat
+    # py2 mypy can't deal with try/excepts
+    _is_py_id = str.isidentifier  # type: ignore[attr-defined]
+except AttributeError:  # Python 2
+    # FIXME: port this to AnsibleCollectionRef.is_valid_collection_name
+    from re import match as _match_pattern
+    from tokenize import Name as _VALID_IDENTIFIER_REGEX
+    _valid_identifier_string_regex = ''.join((_VALID_IDENTIFIER_REGEX, r'\Z'))
+
+    def _is_py_id(tested_str):
+        # Ref: https://stackoverflow.com/a/55802320/595220
+        return bool(_match_pattern(_valid_identifier_string_regex, tested_str))
+
+
+_ALLOW_CONCRETE_POINTER_IN_SOURCE = False  # NOTE: This is a feature flag
+_GALAXY_YAML = b'galaxy.yml'
+_MANIFEST_JSON = b'MANIFEST.json'
+
+
+display = Display()
+
+
+def _is_collection_src_dir(dir_path):
+    b_dir_path = to_bytes(dir_path, errors='surrogate_or_strict')
+    return os.path.isfile(os.path.join(b_dir_path, _GALAXY_YAML))
+
+
+def _is_installed_collection_dir(dir_path):
+    b_dir_path = to_bytes(dir_path, errors='surrogate_or_strict')
+    return os.path.isfile(os.path.join(b_dir_path, _MANIFEST_JSON))
+
+
+def _is_collection_dir(dir_path):
+    return (
+        _is_installed_collection_dir(dir_path) or
+        _is_collection_src_dir(dir_path)
+    )
+
+
+def _find_collections_in_subdirs(dir_path):
+    b_dir_path = to_bytes(dir_path, errors='surrogate_or_strict')
+    galaxy_yml_glob_pattern = os.path.join(
+        b_dir_path,
+        # b'*',  # namespace is supposed to be top-level per spec
+        b'*',  # collection name
+        _GALAXY_YAML,
+    )
+    return (
+        os.path.dirname(galaxy_yml)
+        for galaxy_yml in iglob(galaxy_yml_glob_pattern)
+    )
+
+
+def _is_collection_namespace_dir(tested_str):
+    return any(_find_collections_in_subdirs(tested_str))
+
+
+def _is_file_path(tested_str):
+    return os.path.isfile(to_bytes(tested_str, errors='surrogate_or_strict'))
+
+
+def _is_http_url(tested_str):
+    return urlparse(tested_str).scheme.lower() in {'http', 'https'}
+
+
+def _is_git_url(tested_str):
+    return tested_str.startswith(('git+', 'git@'))
+
+
+def _is_concrete_artifact_pointer(tested_str):
+    return any(
+        predicate(tested_str)
+        for predicate in (
+            # NOTE: Maintain the checks to be sorted from light to heavy:
+            _is_git_url,
+            _is_http_url,
+            _is_file_path,
+            _is_collection_dir,
+            _is_collection_namespace_dir,
+        )
+    )
+
+
+def _is_fqcn(tested_str):
+    # FIXME: port this to AnsibleCollectionRef.is_valid_collection_name
+    if tested_str.count('.') != 1:
+        return False
+
+    return all(
+        # FIXME: keywords and identifiers are different in differnt Pythons
+        not iskeyword(ns_or_name) and _is_py_id(ns_or_name)
+        for ns_or_name in tested_str.split('.')
+    )
+
+
+class _ComputedReqKindsMixin:
+
+    @classmethod
+    def from_dir_path_as_unknown(  # type: ignore[misc]
+            cls,  # type: Type[Collection]
+            dir_path,  # type: bytes
+            art_mgr,  # type: ConcreteArtifactsManager
+    ):  # type: (...)  -> Collection
+        """Make collection from an unspecified dir type.
+
+        This alternative constructor attempts to grab metadata from the
+        given path if it's a directory. If there's no metadata, it
+        falls back to guessing the FQCN based on the directory path and
+        sets the version to "*".
+
+        It raises a ValueError immediatelly if the input is not an
+        existing directory path.
+        """
+        if not os.path.isdir(dir_path):
+            raise ValueError(
+                "The collection directory '{path!s}' doesn't exist".
+                format(path=to_native(dir_path)),
+            )
+
+        try:
+            return cls.from_dir_path(dir_path, art_mgr)
+        except ValueError:
+            return cls.from_dir_path_implicit(dir_path)
+
+    @classmethod
+    def from_dir_path(cls, dir_path, art_mgr):
+        """Make collection from an directory with metadata."""
+        b_dir_path = to_bytes(dir_path, errors='surrogate_or_strict')
+        if not _is_collection_dir(b_dir_path):
+            display.warning(
+                u"Collection at '{path!s}' does not have a {manifest_json!s} "
+                u'file, nor has it {galaxy_yml!s}: cannot detect version.'.
+                format(
+                    galaxy_yml=to_text(_GALAXY_YAML),
+                    manifest_json=to_text(_MANIFEST_JSON),
+                    path=to_text(dir_path, errors='surrogate_or_strict'),
+                ),
+            )
+            raise ValueError(
+                '`dir_path` argument must be an installed or a source'
+                ' collection directory.',
+            )
+
+        tmp_inst_req = cls(None, None, dir_path, 'dir')
+        req_name = art_mgr.get_direct_collection_fqcn(tmp_inst_req)
+        req_version = art_mgr.get_direct_collection_version(tmp_inst_req)
+
+        return cls(req_name, req_version, dir_path, 'dir')
+
+    @classmethod
+    def from_dir_path_implicit(  # type: ignore[misc]
+            cls,  # type: Type[Collection]
+            dir_path,  # type: bytes
+    ):  # type: (...)  -> Collection
+        """Construct a collection instance based on an arbitrary dir.
+
+        This alternative constructor infers the FQCN based on the parent
+        and current directory names. It also sets the version to "*"
+        regardless of whether any of known metadata files are present.
+        """
+        # There is no metadata, but it isn't required for a functional collection. Determine the namespace.name from the path.
+        u_dir_path = to_text(dir_path, errors='surrogate_or_strict')
+        path_list = u_dir_path.split(os.path.sep)
+        req_name = '.'.join(path_list[-2:])
+        return cls(req_name, '*', dir_path, 'dir')  # type: ignore[call-arg]
+
+    @classmethod
+    def from_string(cls, collection_input, artifacts_manager):
+        req = {}
+        if _is_concrete_artifact_pointer(collection_input):
+            # Arg is a file path or URL to a collection
+            req['name'] = collection_input
+        else:
+            req['name'], _sep, req['version'] = collection_input.partition(':')
+            if not req['version']:
+                del req['version']
+
+        return cls.from_requirement_dict(req, artifacts_manager)
+
+    @classmethod
+    def from_requirement_dict(cls, collection_req, art_mgr):
+        req_name = collection_req.get('name', None)
+        req_version = collection_req.get('version', '*')
+        req_type = collection_req.get('type')
+        # TODO: decide how to deprecate the old src API behavior
+        req_source = collection_req.get('source', None)
+
+        if req_type is None:
+            if (  # FIXME: decide on the future behavior:
+                    _ALLOW_CONCRETE_POINTER_IN_SOURCE
+                    and req_source is not None
+                    and _is_concrete_artifact_pointer(req_source)
+            ):
+                src_path = req_source
+            elif req_name is not None and _is_fqcn(req_name):
+                req_type = 'galaxy'
+            elif (
+                    req_name is not None
+                    and _is_concrete_artifact_pointer(req_name)
+            ):
+                src_path, req_name = req_name, None
+            else:
+                dir_tip_tmpl = (  # NOTE: leading LFs are for concat
+                    '\n\nTip: Make sure you are pointing to the right '
+                    'subdirectory — `{src!s}` looks like a directory '
+                    'but it is neither a collection, nor a namespace '
+                    'dir.'
+                )
+
+                if req_source is not None and os.path.isdir(req_source):
+                    tip = dir_tip_tmpl.format(src=req_source)
+                elif req_name is not None and os.path.isdir(req_name):
+                    tip = dir_tip_tmpl.format(src=req_name)
+                elif req_name:
+                    tip = '\n\nCould not find {0}.'.format(req_name)
+                else:
+                    tip = ''
+
+                raise AnsibleError(  # NOTE: I'd prefer a ValueError instead
+                    'Neither the collection requirement entry key '
+                    "'name', nor 'source' point to a concrete "
+                    "resolvable collection artifact. Also 'name' is "
+                    'not an FQCN. A valid collection name must be in '
+                    'the format <namespace>.<collection>. Please make '
+                    'sure that the namespace and the collection name '
+                    ' contain characters from [a-zA-Z0-9_] only.'
+                    '{extra_tip!s}'.format(extra_tip=tip),
+                )
+
+        if req_type is None:
+            if _is_git_url(src_path):
+                req_type = 'git'
+                req_source = src_path
+            elif _is_http_url(src_path):
+                req_type = 'url'
+                req_source = src_path
+            elif _is_file_path(src_path):
+                req_type = 'file'
+                req_source = src_path
+            elif _is_collection_dir(src_path):
+                req_type = 'dir'
+                req_source = src_path
+            elif _is_collection_namespace_dir(src_path):
+                req_name = None  # No name for a virtual req or "namespace."?
+                req_type = 'subdirs'
+                req_source = src_path
+            else:
+                raise AnsibleError(  # NOTE: this is never supposed to be hit
+                    'Failed to automatically detect the collection '
+                    'requirement type.',
+                )
+
+        if req_type not in {'file', 'galaxy', 'git', 'url', 'dir', 'subdirs'}:
+            raise AnsibleError(
+                "The collection requirement entry key 'type' must be "
+                'one of file, galaxy, git, dir, subdirs, or url.'
+            )
+
+        if req_name is None and req_type == 'galaxy':
+            raise AnsibleError(
+                'Collections requirement entry should contain '
+                "the key 'name' if it's requested from a Galaxy-like "
+                'index server.',
+            )
+
+        if req_type != 'galaxy' and req_source is None:
+            req_source, req_name = req_name, None
+
+        if (
+                req_type == 'galaxy' and
+                isinstance(req_source, GalaxyAPI) and
+                not _is_http_url(req_source.api_server)
+        ):
+            raise AnsibleError(
+                "Collections requirement 'source' entry should contain "
+                'a valid Galaxy API URL but it does not: {not_url!s} '
+                'is not an HTTP URL.'.
+                format(not_url=req_source.api_server),
+            )
+
+        tmp_inst_req = cls(req_name, req_version, req_source, req_type)
+
+        if req_type not in {'galaxy', 'subdirs'} and req_name is None:
+            req_name = art_mgr.get_direct_collection_fqcn(tmp_inst_req)  # TODO: fix the cache key in artifacts manager?
+
+        if req_type not in {'galaxy', 'subdirs'} and req_version == '*':
+            req_version = art_mgr.get_direct_collection_version(tmp_inst_req)
+
+        return cls(
+            req_name, req_version,
+            req_source, req_type,
+        )
+
+    def __repr__(self):
+        return (
+            '<{self!s} of type {coll_type!r} from {src!s}>'.
+            format(self=self, coll_type=self.type, src=self.src or 'Galaxy')
+        )
+
+    def __str__(self):
+        return to_native(self.__unicode__())
+
+    def __unicode__(self):
+        if self.fqcn is None:
+            return (
+                u'"virtual collection Git repo"' if self.is_scm
+                else u'"virtual collection namespace"'
+            )
+
+        return (
+            u'{fqcn!s}:{ver!s}'.
+            format(fqcn=to_text(self.fqcn), ver=to_text(self.ver))
+        )
+
+    def _get_separate_ns_n_name(self):  # FIXME: use LRU cache
+        return self.fqcn.split('.')
+
+    @property
+    def namespace(self):
+        if self.is_virtual:
+            raise TypeError('Virtual collections do not have a namespace')
+
+        return self._get_separate_ns_n_name()[0]
+
+    @property
+    def name(self):
+        if self.is_virtual:
+            raise TypeError('Virtual collections do not have a name')
+
+        return self._get_separate_ns_n_name()[-1]
+
+    @property
+    def canonical_package_id(self):
+        if not self.is_virtual:
+            return to_native(self.fqcn)
+
+        return (
+            '<virtual namespace from {src!s} of type {src_type!s}>'.
+            format(src=to_native(self.src), src_type=to_native(self.type))
+        )
+
+    @property
+    def is_virtual(self):
+        return self.is_scm or self.is_subdirs
+
+    @property
+    def is_file(self):
+        return self.type == 'file'
+
+    @property
+    def is_dir(self):
+        return self.type == 'dir'
+
+    @property
+    def namespace_collection_paths(self):
+        return [
+            to_native(path)
+            for path in _find_collections_in_subdirs(self.src)
+        ]
+
+    @property
+    def is_subdirs(self):
+        return self.type == 'subdirs'
+
+    @property
+    def is_url(self):
+        return self.type == 'url'
+
+    @property
+    def is_scm(self):
+        return self.type == 'git'
+
+    @property
+    def is_concrete_artifact(self):
+        return self.type in {'git', 'url', 'file', 'dir', 'subdirs'}
+
+    @property
+    def is_online_index_pointer(self):
+        return not self.is_concrete_artifact
+
+
+class Requirement(
+        _ComputedReqKindsMixin,
+        namedtuple('Requirement', ('fqcn', 'ver', 'src', 'type')),
+):
+    """An abstract requirement request."""
+
+
+class Candidate(
+        _ComputedReqKindsMixin,
+        namedtuple('Candidate', ('fqcn', 'ver', 'src', 'type'))
+):
+    """A concrete collection candidate with its version resolved."""

lib/ansible/galaxy/dependency_resolution/errors.py

@@ -0,0 +1,11 @@
+# -*- coding: utf-8 -*-
+# Copyright: (c) 2020-2021, Ansible Project
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+"""Dependency resolution exceptions."""
+
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+from resolvelib.resolvers import (
+    ResolutionImpossible as CollectionDependencyResolutionImpossible,
+)

lib/ansible/galaxy/dependency_resolution/providers.py

@@ -0,0 +1,273 @@
+# -*- coding: utf-8 -*-
+# Copyright: (c) 2020-2021, Ansible Project
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+"""Requirement provider interfaces."""
+
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+import functools
+
+try:
+    from typing import TYPE_CHECKING
+except ImportError:
+    TYPE_CHECKING = False
+
+if TYPE_CHECKING:
+    from typing import Iterable, List, NamedTuple, Optional, Union
+    from ansible.galaxy.collection.concrete_artifact_manager import (
+        ConcreteArtifactsManager,
+    )
+    from ansible.galaxy.collection.galaxy_api_proxy import MultiGalaxyAPIProxy
+
+from ansible.galaxy.dependency_resolution.dataclasses import (
+    Candidate,
+    Requirement,
+)
+from ansible.galaxy.dependency_resolution.versioning import (
+    is_pre_release,
+    meets_requirements,
+)
+from ansible.utils.version import SemanticVersion
+
+from resolvelib import AbstractProvider
+
+
+class CollectionDependencyProvider(AbstractProvider):
+    """Delegate providing a requirement interface for the resolver."""
+
+    def __init__(
+            self,  # type: CollectionDependencyProvider
+            apis,  # type: MultiGalaxyAPIProxy
+            concrete_artifacts_manager=None,  # type: ConcreteArtifactsManager
+            preferred_candidates=None,  # type: Iterable[Candidate]
+            with_deps=True,  # type: bool
+            with_pre_releases=False,  # type: bool
+    ):  # type: (...) -> None
+        r"""Initialize helper attributes.
+
+        :param api: An instance of the multiple Galaxy APIs wrapper.
+
+        :param concrete_artifacts_manager: An instance of the caching \
+                                           concrete artifacts manager.
+
+        :param with_deps: A flag specifying whether the resolver \
+                          should attempt to pull-in the deps of the \
+                          requested requirements. On by default.
+
+        :param with_pre_releases: A flag specifying whether the \
+                                  resolver should skip pre-releases. \
+                                  Off by default.
+        """
+        self._api_proxy = apis
+        self._make_req_from_dict = functools.partial(
+            Requirement.from_requirement_dict,
+            art_mgr=concrete_artifacts_manager,
+        )
+        self._preferred_candidates = set(preferred_candidates or ())
+        self._with_deps = with_deps
+        self._with_pre_releases = with_pre_releases
+
+    def identify(self, requirement_or_candidate):
+        # type: (Union[Candidate, Requirement]) -> str
+        """Given requirement or candidate, return an identifier for it.
+
+        This is used to identify a requirement or candidate, e.g.
+        whether two requirements should have their specifier parts
+        (version ranges or pins) merged, whether two candidates would
+        conflict with each other (because they have same name but
+        different versions).
+        """
+        return requirement_or_candidate.canonical_package_id
+
+    def get_preference(
+            self,  # type: CollectionDependencyProvider
+            resolution,  # type: Optional[Candidate]
+            candidates,  # type: List[Candidate]
+            information,  # type: List[NamedTuple]
+    ):  # type: (...) -> Union[float, int]
+        """Return sort key function return value for given requirement.
+
+        This result should be based on preference that is defined as
+        "I think this requirement should be resolved first".
+        The lower the return value is, the more preferred this
+        group of arguments is.
+
+        :param resolution: Currently pinned candidate, or ``None``.
+
+        :param candidates: A list of possible candidates.
+
+        :param information: A list of requirement information.
+
+        Each ``information`` instance is a named tuple with two entries:
+
+          * ``requirement`` specifies a requirement contributing to
+            the current candidate list
+
+          * ``parent`` specifies the candidate that provides
+            (dependend on) the requirement, or `None`
+            to indicate a root requirement.
+
+        The preference could depend on a various of issues, including
+        (not necessarily in this order):
+
+          * Is this package pinned in the current resolution result?
+
+          * How relaxed is the requirement? Stricter ones should
+            probably be worked on first? (I don't know, actually.)
+
+          * How many possibilities are there to satisfy this
+            requirement? Those with few left should likely be worked on
+            first, I guess?
+
+          * Are there any known conflicts for this requirement?
+            We should probably work on those with the most
+            known conflicts.
+
+        A sortable value should be returned (this will be used as the
+        `key` parameter of the built-in sorting function). The smaller
+        the value is, the more preferred this requirement is (i.e. the
+        sorting function is called with ``reverse=False``).
+        """
+        if any(
+                candidate in self._preferred_candidates
+                for candidate in candidates
+        ):
+            # NOTE: Prefer pre-installed candidates over newer versions
+            # NOTE: available from Galaxy or other sources.
+            return float('-inf')
+        return len(candidates)
+
+    def find_matches(self, requirements):
+        # type: (List[Requirement]) -> List[Candidate]
+        r"""Find all possible candidates satisfying given requirements.
+
+        This tries to get candidates based on the requirements' types.
+
+        For concrete requirements (SCM, dir, namespace dir, local or
+        remote archives), the one-and-only match is returned
+
+        For a "named" requirement, Galaxy-compatible APIs are consulted
+        to find concrete candidates for this requirement. Of theres a
+        pre-installed candidate, it's prepended in front of others.
+
+        :param requirements: A collection of requirements which all of \
+                             the returned candidates must match. \
+                             All requirements are guaranteed to have \
+                             the same identifier. \
+                             The collection is never empty.
+
+        :returns: An iterable that orders candidates by preference, \
+                  e.g. the most preferred candidate comes first.
+        """
+        # FIXME: The first requirement may be a Git repo followed by
+        # FIXME: its cloned tmp dir. Using only the first one creates
+        # FIXME: loops that prevent any further dependency exploration.
+        # FIXME: We need to figure out how to prevent this.
+        first_req = requirements[0]
+        fqcn = first_req.fqcn
+        # The fqcn is guaranteed to be the same
+        coll_versions = self._api_proxy.get_collection_versions(first_req)
+        if first_req.is_concrete_artifact:
+            # FIXME: do we assume that all the following artifacts are also concrete?
+            # FIXME: does using fqcn==None cause us problems here?
+
+            return [
+                Candidate(fqcn, version, _none_src_server, first_req.type)
+                for version, _none_src_server in coll_versions
+            ]
+
+        preinstalled_candidates = {
+            candidate for candidate in self._preferred_candidates
+            if candidate.fqcn == fqcn
+        }
+
+        return list(preinstalled_candidates) + sorted(
+            {
+                candidate for candidate in (
+                    Candidate(fqcn, version, src_server, 'galaxy')
+                    for version, src_server in coll_versions
+                )
+                if all(self.is_satisfied_by(requirement, candidate) for requirement in requirements)
+                # FIXME
+                # if all(self.is_satisfied_by(requirement, candidate) and (
+                #     requirement.src is None or  # if this is true for some candidates but not all it will break key param - Nonetype can't be compared to str
+                #     requirement.src == candidate.src
+                # ))
+            },
+            key=lambda candidate: (
+                SemanticVersion(candidate.ver), candidate.src,
+            ),
+            reverse=True,  # prefer newer versions over older ones
+        )
+
+    def is_satisfied_by(self, requirement, candidate):
+        # type: (Requirement, Candidate) -> bool
+        r"""Whether the given requirement is satisfiable by a candidate.
+
+        :param requirement: A requirement that produced the `candidate`.
+
+        :param candidate: A pinned candidate supposedly matchine the \
+                          `requirement` specifier. It is guaranteed to \
+                          have been generated from the `requirement`.
+
+        :returns: Indication whether the `candidate` is a viable \
+                  solution to the `requirement`.
+        """
+        # NOTE: Only allow pre-release candidates if we want pre-releases or
+        # the req ver was an exact match with the pre-release version.
+        allow_pre_release = self._with_pre_releases or not (
+            requirement.ver == '*' or
+            requirement.ver.startswith('<') or
+            requirement.ver.startswith('>') or
+            requirement.ver.startswith('!=')
+        )
+        if is_pre_release(candidate.ver) and not allow_pre_release:
+            return False
+
+        # NOTE: This is a set of Pipenv-inspired optimizations. Ref:
+        # https://github.com/sarugaku/passa/blob/2ac00f1/src/passa/models/providers.py#L58-L74
+        if (
+                requirement.is_virtual or
+                candidate.is_virtual or
+                requirement.ver == '*'
+        ):
+            return True
+
+        return meets_requirements(
+            version=candidate.ver,
+            requirements=requirement.ver,
+        )
+
+    def get_dependencies(self, candidate):
+        # type: (Candidate) -> List[Candidate]
+        r"""Get direct dependencies of a candidate.
+
+        :returns: A collection of requirements that `candidate` \
+                  specifies as its dependencies.
+        """
+        # FIXME: If there's several galaxy servers set, there may be a
+        # FIXME: situation when the metadata of the same collection
+        # FIXME: differs. So how do we resolve this case? Priority?
+        # FIXME: Taking into account a pinned hash? Exploding on
+        # FIXME: any differences?
+        # NOTE: The underlying implmentation currently uses first found
+        req_map = self._api_proxy.get_collection_dependencies(candidate)
+
+        # NOTE: This guard expression MUST perform an early exit only
+        # NOTE: after the `get_collection_dependencies()` call because
+        # NOTE: internally it polulates the artifact URL of the candidate,
+        # NOTE: its SHA hash and the Galaxy API token. These are still
+        # NOTE: necessary with `--no-deps` because even with the disabled
+        # NOTE: dependency resolution the outer layer will still need to
+        # NOTE: know how to download and validate the artifact.
+        #
+        # NOTE: Virtual candidates should always return dependencies
+        # NOTE: because they are ephemeral and non-installable.
+        if not self._with_deps and not candidate.is_virtual:
+            return []
+
+        return [
+            self._make_req_from_dict({'name': dep_name, 'version': dep_req})
+            for dep_name, dep_req in req_map.items()
+        ]

lib/ansible/galaxy/dependency_resolution/reporters.py

@@ -0,0 +1,17 @@
+# -*- coding: utf-8 -*-
+# Copyright: (c) 2020-2021, Ansible Project
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+"""Requiement reporter implementations."""
+
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+from resolvelib import BaseReporter
+
+
+class CollectionDependencyReporter(BaseReporter):
+    """A dependency reporter for Ansible Collections.
+
+    This is a proxy class allowing us to abstract away importing resolvelib
+    outside of the `ansible.galaxy.dependency_resolution` Python package.
+    """

lib/ansible/galaxy/dependency_resolution/resolvers.py

@@ -0,0 +1,17 @@
+# -*- coding: utf-8 -*-
+# Copyright: (c) 2020-2021, Ansible Project
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+"""Requirement resolver implementations."""
+
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+from resolvelib import Resolver
+
+
+class CollectionDependencyResolver(Resolver):
+    """A dependency resolver for Ansible Collections.
+
+    This is a proxy class allowing us to abstract away importing resolvelib
+    outside of the `ansible.galaxy.dependency_resolution` Python package.
+    """

lib/ansible/galaxy/dependency_resolution/versioning.py

@@ -15,7 +15,10 @@ from ansible.utils.version import SemanticVersion
 def is_pre_release(version):
     # type: (str) -> bool
     """Figure out if a given version is a pre-release."""
+    try:
         return SemanticVersion(version).is_prerelease
+    except ValueError:
+        return False
 
 
 def meets_requirements(version, requirements):

requirements.txt

@@ -7,3 +7,7 @@ jinja2
 PyYAML
 cryptography
 packaging
+# NOTE: resolvelib 0.x version bumps should be considered major/breaking
+# NOTE: and we should update the upper cap with care, at least until 1.0
+# NOTE: Ref: https://github.com/sarugaku/resolvelib/issues/69
+resolvelib >= 0.5.3, < 0.6.0  # dependency resolver used by ansible-galaxy

test/integration/targets/ansible-galaxy-collection-scm/tasks/download.yml

@@ -24,8 +24,8 @@
 
 - assert:
     that:
-      - '"Downloading collection ''amazon.aws'' to" in download_collection.stdout'
+      - '"Downloading collection ''amazon.aws:1.0.0'' to" in download_collection.stdout'
-      - '"Downloading collection ''awx.awx'' to" in download_collection.stdout'
+      - '"Downloading collection ''awx.awx:0.0.1-devel'' to" in download_collection.stdout'
       - download_collection_amazon_actual.stat.exists
       - download_collection_awx_actual.stat.exists
 

test/integration/targets/ansible-galaxy-collection-scm/tasks/reinstalling.yml

@@ -2,22 +2,23 @@
   command: 'ansible-galaxy collection install git+file://{{ galaxy_dir }}/development/ansible_test/.git#/collection_1/'
   register: installed
 
-- assert:
+- name: SCM collections don't have a concrete artifact version so the collection should always be reinstalled
+  assert:
     that:
-      - "'Skipping' in installed.stdout"
+      - "'Created collection for ansible_test.collection_1' in installed.stdout"
-      - "'Created' not in installed.stdout"
+      - "'Created collection for ansible_test.collection_2' in installed.stdout"
 
-- name: Only reinstall the collection
+- name: The collection should also be reinstalled when --force flag is used
   command: 'ansible-galaxy collection install git+file://{{ galaxy_dir }}/development/ansible_test/.git#/collection_1/ --force'
   register: installed
 
 - assert:
     that:
       - "'Created collection for ansible_test.collection_1' in installed.stdout"
-      - "'Created collection for ansible_test.collection_2' not in installed.stdout"
+      # The dependency is also an SCM collection, so it should also be reinstalled
-      - "'Skipping' in installed.stdout"
+      - "'Created collection for ansible_test.collection_2' in installed.stdout"
 
-- name: Reinstall the collection and dependency
+- name: The collection should also be reinstalled when --force-with-deps is used
   command: 'ansible-galaxy collection install git+file://{{ galaxy_dir }}/development/ansible_test/.git#/collection_1/ --force-with-deps'
   register: installed
 
@@ -25,7 +26,6 @@
     that:
       - "'Created collection for ansible_test.collection_1' in installed.stdout"
       - "'Created collection for ansible_test.collection_2' in installed.stdout"
-      - "'Skipping' not in installed.stdout"
 
 - include_tasks: ./empty_installed_collections.yml
   when: cleanup

test/integration/targets/ansible-galaxy-collection-scm/tasks/requirements.yml

@@ -25,7 +25,13 @@
 - assert:
     that:
       - result.failed
-      - '"ERROR! Collections requirement entry should contain the key name." in result.stderr'
+      - >-
+        "ERROR! Neither the collection requirement entry key 'name',
+        nor 'source' point to a concrete resolvable collection artifact.
+        Also 'name' is not an FQCN. A valid collection name must be in
+        the format <namespace>.<collection>. Please make sure that the
+        namespace and the collection name  contain characters from
+        [a-zA-Z0-9_] only." in result.stderr
 
 - name: test source is not a git repo even if name is provided
   command: 'ansible-galaxy collection install -r source_and_name.yml'
@@ -37,7 +43,10 @@
 - assert:
     that:
       - result.failed
-      - '"ERROR! Unknown error when attempting to call Galaxy" in result.stderr'
+      - >-
+        result.stderr is search("ERROR! Collections requirement 'source'
+        entry should contain a valid Galaxy API URL but it does not:
+        git\+file:///.*/amazon.aws/.git is not an HTTP URL.")
 
 - name: test source is not a git repo even if name and type is provided
   command: 'ansible-galaxy collection install -r source_and_name_and_type.yml'
@@ -49,7 +58,12 @@
 - assert:
     that:
       - result.failed
-      - 'result.stderr is search("ERROR! - command /.*/git clone ansible.nope ansible.nope failed")'
+      - >-
+        result.stderr is search("ERROR! Failed to clone a Git repository
+        from `file:///.*/.git`.")
+      - >-
+        result.stderr is search("fatal: '/.*/amazon.aws/.git' does not
+        appear to be a git repository")
 
 - name: test using name as a git repo without git+ prefix
   command: 'ansible-galaxy collection install -r name_without_type.yml'

test/integration/targets/ansible-galaxy-collection-scm/tasks/scm_dependency_deduplication.yml

@@ -4,16 +4,35 @@
 
 - assert:
     that:
-      - command.stdout_lines | length == 9
+      - command.stdout_lines | length == 12
-      - command.stdout_lines[0] == "Starting galaxy collection install process"
+      - >-
-      - command.stdout_lines[1] == "Process install dependency map"
+        'Starting galaxy collection install process'
-      - command.stdout_lines[2] == "Starting collection install process"
+        in command.stdout_lines
-      - "'namespace_1.collection_1' in command.stdout_lines[3]"
+      - >-
-      - "'namespace_1.collection_1' in command.stdout_lines[4]"
+        'Starting collection install process'
-      - "'namespace_1.collection_1' in command.stdout_lines[5]"
+        in command.stdout_lines
-      - "'namespace_2.collection_2' in command.stdout_lines[6]"
+      - >-
-      - "'namespace_2.collection_2' in command.stdout_lines[7]"
+        "Installing 'namespace_1.collection_1:1.0.0' to
-      - "'namespace_2.collection_2' in command.stdout_lines[8]"
+        '{{ galaxy_dir }}/ansible_collections/namespace_1/collection_1'"
+        in command.stdout_lines
+      - >-
+        'Created collection for namespace_1.collection_1:1.0.0 at
+        {{ galaxy_dir }}/ansible_collections/namespace_1/collection_1'
+        in command.stdout_lines
+      - >-
+        'namespace_1.collection_1:1.0.0 was installed successfully'
+        in command.stdout_lines
+      - >-
+        "Installing 'namespace_2.collection_2:1.0.0' to
+        '{{ galaxy_dir }}/ansible_collections/namespace_2/collection_2'"
+        in command.stdout_lines
+      - >-
+        'Created collection for namespace_2.collection_2:1.0.0 at
+        {{ galaxy_dir }}/ansible_collections/namespace_2/collection_2'
+        in command.stdout_lines
+      - >-
+        'namespace_2.collection_2:1.0.0 was installed successfully'
+        in command.stdout_lines
 
 - name: list installed collections
   command: 'ansible-galaxy collection list'
@@ -30,16 +49,35 @@
 
 - assert:
     that:
-      - command.stdout_lines | length == 9
+      - command.stdout_lines | length == 12
-      - command.stdout_lines[0] == "Starting galaxy collection install process"
+      - >-
-      - command.stdout_lines[1] == "Process install dependency map"
+        'Starting galaxy collection install process'
-      - command.stdout_lines[2] == "Starting collection install process"
+        in command.stdout_lines
-      - "'namespace_1.collection_1' in command.stdout_lines[3]"
+      - >-
-      - "'namespace_1.collection_1' in command.stdout_lines[4]"
+        'Starting collection install process'
-      - "'namespace_1.collection_1' in command.stdout_lines[5]"
+        in command.stdout_lines
-      - "'namespace_2.collection_2' in command.stdout_lines[6]"
+      - >-
-      - "'namespace_2.collection_2' in command.stdout_lines[7]"
+        "Installing 'namespace_1.collection_1:1.0.0' to
-      - "'namespace_2.collection_2' in command.stdout_lines[8]"
+        '{{ galaxy_dir }}/ansible_collections/namespace_1/collection_1'"
+        in command.stdout_lines
+      - >-
+        'Created collection for namespace_1.collection_1:1.0.0 at
+        {{ galaxy_dir }}/ansible_collections/namespace_1/collection_1'
+        in command.stdout_lines
+      - >-
+        'namespace_1.collection_1:1.0.0 was installed successfully'
+        in command.stdout_lines
+      - >-
+        "Installing 'namespace_2.collection_2:1.0.0' to
+        '{{ galaxy_dir }}/ansible_collections/namespace_2/collection_2'"
+        in command.stdout_lines
+      - >-
+        'Created collection for namespace_2.collection_2:1.0.0 at
+        {{ galaxy_dir }}/ansible_collections/namespace_2/collection_2'
+        in command.stdout_lines
+      - >-
+        'namespace_2.collection_2:1.0.0 was installed successfully'
+        in command.stdout_lines
 
 - name: list installed collections
   command: 'ansible-galaxy collection list'

test/integration/targets/ansible-galaxy-collection/tasks/download.yml

@@ -16,12 +16,18 @@
     file_type: file
   register: download_collection_actual
 
-- name: assert download collection with multiple dependencies
+- name: assert download collection with multiple dependencies --no-deps
   assert:
     that:
-    - '"Downloading collection ''parent_dep.parent_collection'' to" in download_collection.stdout'
+    - >-
-    - 'not "Downloading collection ''child_dep.child_collection'' to" in download_collection.stdout'
+      "Downloading collection 'parent_dep.parent_collection:1.0.0' to '/tmp/"
-    - 'not "Downloading collection ''child_dep.child_dep2'' to" in download_collection.stdout'
+      in download_collection.stdout
+    - >-
+      "Downloading collection 'child_dep.child_collection"
+      not in download_collection.stdout
+    - >-
+      "Downloading collection 'child_dep.child_dep2"
+      not in download_collection.stdout
     - download_collection_actual.examined == 2
     - download_collection_actual.matched == 2
     - (download_collection_actual.files[0].path | basename) in ['requirements.yml', 'parent_dep-parent_collection-1.0.0.tar.gz']
@@ -42,9 +48,9 @@
 - name: assert download collection with multiple dependencies
   assert:
     that:
-    - '"Downloading collection ''parent_dep.parent_collection'' to" in download_collection.stdout'
+    - '"Downloading collection ''parent_dep.parent_collection:1.0.0'' to" in download_collection.stdout'
-    - '"Downloading collection ''child_dep.child_collection'' to" in download_collection.stdout'
+    - '"Downloading collection ''child_dep.child_collection:0.9.9'' to" in download_collection.stdout'
-    - '"Downloading collection ''child_dep.child_dep2'' to" in download_collection.stdout'
+    - '"Downloading collection ''child_dep.child_dep2:1.2.2'' to" in download_collection.stdout'
     - download_collection_actual.examined == 4
     - download_collection_actual.matched == 4
     - (download_collection_actual.files[0].path | basename) in ['requirements.yml', 'child_dep-child_dep2-1.2.2.tar.gz', 'child_dep-child_collection-0.9.9.tar.gz', 'parent_dep-parent_collection-1.0.0.tar.gz']
@@ -104,7 +110,7 @@
 - name: assert download collection with multiple dependencies
   assert:
     that:
-    - '"Downloading collection ''namespace1.name1'' to" in download_req_custom_path.stdout'
+    - '"Downloading collection ''namespace1.name1:1.1.0-beta.1'' to" in download_req_custom_path.stdout'
     - download_req_custom_path_actual.examined == 2
     - download_req_custom_path_actual.matched == 2
     - (download_req_custom_path_actual.files[0].path | basename) in ['requirements.yml', 'namespace1-name1-1.1.0-beta.1.tar.gz']
@@ -161,5 +167,5 @@
 
     - assert:
         that:
-        - '"Downloading collection ''ansible_test.my_collection'' to" in download_collection.stdout'
+        - '"Downloading collection ''ansible_test.my_collection:1.0.0'' to" in download_collection.stdout'
         - download_collection_actual.stat.exists

test/integration/targets/ansible-galaxy-collection/tasks/install.yml

@@ -40,7 +40,7 @@
 - name: assert install existing without --force - {{ test_name }}
   assert:
     that:
-    - '"Skipping ''namespace1.name1'' as it is already installed" in install_existing_no_force.stdout'
+    - '"Nothing to do. All requested collections are already installed" in install_existing_no_force.stdout'
 
 - name: install existing with --force - {{ test_name }}
   command: ansible-galaxy collection install namespace1.name1 -s '{{ test_name }}' --force {{ galaxy_verbosity }}
@@ -129,7 +129,9 @@
 - name: expect failure with dep resolution failure
   command:  ansible-galaxy collection install fail_namespace.fail_collection -s {{ test_name }} {{ galaxy_verbosity }}
   register: fail_dep_mismatch
-  failed_when: '"Cannot meet dependency requirement ''fail_dep2.name:<0.0.5'' for collection fail_namespace.fail_collection" not in fail_dep_mismatch.stderr'
+  failed_when:
+  - '"Could not satisfy the following requirements" not in fail_dep_mismatch.stderr'
+  - '" fail_dep2.name:<0.0.5 (dependency of fail_namespace.fail_collection:2.1.2)" not in fail_dep_mismatch.stderr'
 
 - name: Find artifact url for namespace3.name
   uri:

test/integration/targets/ansible-galaxy-collection/tasks/list.yml

@@ -0,0 +1,55 @@
+- name: initialize collection structure
+  command: ansible-galaxy collection init {{ item }} --init-path "{{ galaxy_dir }}/dev/ansible_collections" {{ galaxy_verbosity }}
+  loop:
+    - 'dev.collection1'
+    - 'dev.collection2'
+    - 'dev.collection3'
+
+- name: replace the default version of the collections
+  lineinfile:
+    path: "{{ galaxy_dir }}/dev/ansible_collections/dev/{{ item.name }}/galaxy.yml"
+    line: "{{ item.version }}"
+    regexp: "version: .*"
+  loop:
+    - name: "collection1"
+      version: "version: null"
+    - name: "collection2"
+      version: "version: placeholder"
+    - name: "collection3"
+      version: "version: ''"
+
+- name: list collections in development without semver versions
+  command: ansible-galaxy collection list {{ galaxy_verbosity }}
+  register: list_result
+  environment:
+    ANSIBLE_COLLECTIONS_PATH: "{{ galaxy_dir }}/dev:{{ galaxy_dir }}/prod"
+
+- assert:
+    that:
+      - "'dev.collection1 *' in list_result.stdout"
+      # Note the version displayed is the 'placeholder' string rather than "*" since it is not falsey
+      - "'dev.collection2 placeholder' in list_result.stdout"
+      - "'dev.collection3 *' in list_result.stdout"
+
+- name: install an artifact to the second collections path
+  command: ansible-galaxy collection install namespace1.name1 -s galaxy_ng {{ galaxy_verbosity }} -p "{{ galaxy_dir }}/prod"
+  environment:
+    ANSIBLE_CONFIG: '{{ galaxy_dir }}/ansible.cfg'
+
+- name: replace the artifact version
+  lineinfile:
+    path: "{{ galaxy_dir }}/prod/ansible_collections/namespace1/name1/MANIFEST.json"
+    line: '  "version": null,'
+    regexp: '  "version": .*'
+
+- name: test listing collections in all paths
+  command: ansible-galaxy collection list {{ galaxy_verbosity }}
+  register: list_result
+  ignore_errors: True
+  environment:
+    ANSIBLE_COLLECTIONS_PATH: "{{ galaxy_dir }}/dev:{{ galaxy_dir }}/prod"
+
+- assert:
+    that:
+      - list_result is failed
+      - "'is expected to have a valid SemVer version value but got None' in list_result.stderr"

test/integration/targets/ansible-galaxy-collection/tasks/main.yml

@@ -144,34 +144,24 @@
 - name: assert result of install collection with dep on another server
   assert:
     that:
-    - '"''secondary.name'' obtained from server secondary" in install_cross_dep.stdout'
+    - >-
+      "'secondary.name:1.0.0' obtained from server secondary"
+      in install_cross_dep.stdout
     # pulp_v2 is highest in the list so it will find it there first
-    - '"''parent_dep.parent_collection'' obtained from server pulp_v2" in install_cross_dep.stdout'
+    - >-
-    - '"''child_dep.child_collection'' obtained from server pulp_v2" in install_cross_dep.stdout'
+      "'parent_dep.parent_collection:1.0.0' obtained from server pulp_v2"
-    - '"''child_dep.child_dep2'' obtained from server pulp_v2" in install_cross_dep.stdout'
+      in install_cross_dep.stdout
+    - >-
+      "'child_dep.child_collection:0.9.9' obtained from server pulp_v2"
+      in install_cross_dep.stdout
+    - >-
+      "'child_dep.child_dep2:1.2.2' obtained from server pulp_v2"
+      in install_cross_dep.stdout
     - (install_cross_dep_actual.results[0].content | b64decode | from_json).collection_info.version == '1.0.0'
     - (install_cross_dep_actual.results[1].content | b64decode | from_json).collection_info.version == '1.0.0'
     - (install_cross_dep_actual.results[2].content | b64decode | from_json).collection_info.version == '0.9.9'
     - (install_cross_dep_actual.results[3].content | b64decode | from_json).collection_info.version == '1.2.2'
 
-# fake.fake does not exist but we check the output to ensure it checked all 3
-# servers defined in the config. We hardcode to -vvv as that's what level the
-# message is shown
-- name: test install fallback on server list
-  command: ansible-galaxy collection install fake.fake -vvv
-  ignore_errors: yes
-  environment:
-    ANSIBLE_CONFIG: '{{ galaxy_dir }}/ansible.cfg'
-  register: missing_fallback
-
-- name: assert test install fallback on server list
-  assert:
-    that:
-    - missing_fallback.rc == 1
-    - '"Collection ''fake.fake'' is not available from server pulp_v2" in missing_fallback.stdout'
-    - '"Collection ''fake.fake'' is not available from server pulp_v3" in missing_fallback.stdout'
-    - '"Collection ''fake.fake'' is not available from server galaxy_ng" in missing_fallback.stdout'
-
 - name: run ansible-galaxy collection download tests
   include_tasks: download.yml
   args:
@@ -189,3 +179,6 @@
     test_name: 'galaxy_ng'
     test_server: '{{ galaxy_ng_server }}'
     vX: "v3/"
+
+- name: run ansible-galaxy collection list tests
+  include_tasks: list.yml

test/integration/targets/ansible-galaxy-collection/tasks/verify.yml

@@ -21,7 +21,8 @@
 - assert:
     that:
       - verify.failed
-      - "'The format namespace.name is expected' in verify.stderr"
+      - >-
+        "ERROR! 'file' type is not supported. The format namespace.name is expected." in verify.stderr
 
 - name: install the collection from the server
   command: ansible-galaxy collection install ansible_test.verify:1.0.0
@@ -39,6 +40,11 @@
       - verify is success
       - "'Collection ansible_test.verify contains modified content' not in verify.stdout"
 
+- name: verify the installed collection against the server, with unspecified version in CLI
+  command: ansible-galaxy collection verify ansible_test.verify
+  environment:
+    ANSIBLE_COLLECTIONS_PATH: '{{ galaxy_dir }}'
+
 - name: verify a collection that doesn't appear to be installed
   command: ansible-galaxy collection verify ansible_test.verify:1.0.0
   register: verify

test/lib/ansible_test/_data/requirements/constraints.txt

@@ -1,3 +1,4 @@
+resolvelib >= 0.5.3, < 0.6.0  # keep in sync with `requirements.txt`
 coverage >= 4.5.1, < 5.0.0 ; python_version <  '3.7' # coverage 4.4 required for "disable_warnings" support but 4.5.1 needed for bug fixes, coverage 5.0+ incompatible
 coverage >= 4.5.2, < 5.0.0 ; python_version == '3.7' # coverage 4.5.2 fixes bugs in support for python 3.7, coverage 5.0+ incompatible
 coverage >= 4.5.4, < 5.0.0 ; python_version >  '3.7' # coverage had a bug in < 4.5.4 that would cause unit tests to hang in Python 3.8, coverage 5.0+ incompatible

test/lib/ansible_test/_data/requirements/integration.txt

@@ -4,3 +4,4 @@ junit-xml
 ordereddict ; python_version < '2.7'
 packaging
 pyyaml
+resolvelib

test/lib/ansible_test/_data/requirements/units.txt

@@ -5,3 +5,4 @@ pytest
 pytest-mock
 pytest-xdist
 pyyaml
+resolvelib

test/sanity/code-smell/docs-build.requirements.txt

@@ -1,5 +1,6 @@
 jinja2
 pyyaml
+resolvelib
 sphinx
 sphinx-notfound-page
 straight.plugin

test/sanity/code-smell/package-data.requirements.txt

@@ -2,6 +2,7 @@ docutils
 jinja2
 packaging
 pyyaml  # ansible-core requirement
+resolvelib  # ansible-core requirement
 rstcheck
 setuptools > 39.2
 straight.plugin

test/sanity/ignore.txt

@@ -41,7 +41,11 @@ lib/ansible/executor/powershell/async_watchdog.ps1 pslint:PSCustomUseLiteralPath
 lib/ansible/executor/powershell/async_wrapper.ps1 pslint:PSCustomUseLiteralPath
 lib/ansible/executor/powershell/exec_wrapper.ps1 pslint:PSCustomUseLiteralPath
 lib/ansible/executor/task_queue_manager.py pylint:blacklisted-name
+lib/ansible/cli/galaxy.py compile-2.6!skip  # 'ansible-galaxy collection' requires 2.7+
 lib/ansible/galaxy/collection/__init__.py compile-2.6!skip # 'ansible-galaxy collection' requires 2.7+
+lib/ansible/galaxy/collection/galaxy_api_proxy.py compile-2.6!skip  # 'ansible-galaxy collection' requires 2.7+
+lib/ansible/galaxy/dependency_resolution/dataclasses.py compile-2.6!skip  # 'ansible-galaxy collection' requires 2.7+
+lib/ansible/galaxy/dependency_resolution/providers.py compile-2.6!skip  # 'ansible-galaxy collection' requires 2.7+
 lib/ansible/module_utils/compat/_selectors2.py future-import-boilerplate # ignore bundled
 lib/ansible/module_utils/compat/_selectors2.py metaclass-boilerplate # ignore bundled
 lib/ansible/module_utils/compat/_selectors2.py pylint:blacklisted-name

test/units/cli/galaxy/test_display_collection.py

@@ -8,14 +8,13 @@ __metaclass__ = type
 import pytest
 
 from ansible.cli.galaxy import _display_collection
+from ansible.galaxy.dependency_resolution.dataclasses import Requirement
 
 
 @pytest.fixture
-def collection_object(mocker):
+def collection_object():
     def _cobj(fqcn='sandwiches.ham'):
-        cobj = mocker.MagicMock(latest_version='1.5.0')
+        return Requirement(fqcn, '1.5.0', None, 'galaxy')
-        cobj.__str__.return_value = fqcn
-        return cobj
     return _cobj
 
 

test/units/cli/galaxy/test_execute_list_collection.py

@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 # Copyright (c) 2020 Ansible Project
 # GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
 
@@ -9,7 +10,8 @@ import pytest
 from ansible import context
 from ansible.cli.galaxy import GalaxyCLI
 from ansible.errors import AnsibleError, AnsibleOptionsError
-from ansible.galaxy.collection import CollectionRequirement
+from ansible.galaxy import collection
+from ansible.galaxy.dependency_resolution.dataclasses import Requirement
 from ansible.module_utils._text import to_native
 
 
@@ -48,47 +50,39 @@ def mock_collection_objects(mocker):
     mocker.patch('ansible.cli.galaxy.validate_collection_path',
                  side_effect=['/root/.ansible/collections/ansible_collections', '/usr/share/ansible/collections/ansible_collections'])
 
-    collection_args = (
+    collection_args_1 = (
         (
-            'sandwiches',
+            'sandwiches.pbj',
-            'pbj',
-            b'/usr/share/ansible/collections/ansible_collections/sandwiches/pbj',
-            mocker.Mock(),
-            ['1.0.0', '1.5.0'],
-            '1.0.0',
-            False,
-        ),
-        (
-            'sandwiches',
-            'pbj',
-            b'/root/.ansible/collections/ansible_collections/sandwiches/pbj',
-            mocker.Mock(),
-            ['1.0.0', '1.5.0'],
             '1.5.0',
-            False,
+            None,
+            'dir',
         ),
         (
-            'sandwiches',
+            'sandwiches.reuben',
-            'ham',
-            b'/usr/share/ansible/collections/ansible_collections/sandwiches/ham',
-            mocker.Mock(),
-            ['1.0.0'],
-            '1.0.0',
-            False,
-        ),
-        (
-            'sandwiches',
-            'reuben',
-            b'/root/.ansible/collections/ansible_collections/sandwiches/reuben',
-            mocker.Mock(),
-            ['1.0.0', '2.5.0'],
             '2.5.0',
-            False,
+            None,
+            'dir',
         ),
     )
 
-    collections_path_1 = [CollectionRequirement(*cargs) for cargs in collection_args if to_native(cargs[2]).startswith('/root')]
+    collection_args_2 = (
-    collections_path_2 = [CollectionRequirement(*cargs) for cargs in collection_args if to_native(cargs[2]).startswith('/usr/share')]
+        (
+            'sandwiches.pbj',
+            '1.0.0',
+            None,
+            'dir',
+        ),
+        (
+            'sandwiches.ham',
+            '1.0.0',
+            None,
+            'dir',
+        ),
+    )
+
+    collections_path_1 = [Requirement(*cargs) for cargs in collection_args_1]
+    collections_path_2 = [Requirement(*cargs) for cargs in collection_args_2]
+
     mocker.patch('ansible.cli.galaxy.find_existing_collections', side_effect=[collections_path_1, collections_path_2])
 
 
@@ -98,44 +92,35 @@ def mock_from_path(mocker):
         collection_args = {
             'sandwiches.pbj': (
                 (
-                    'sandwiches',
+                    'sandwiches.pbj',
-                    'pbj',
-                    b'/root/.ansible/collections/ansible_collections/sandwiches/pbj',
-                    mocker.Mock(),
-                    ['1.0.0', '1.5.0'],
                     '1.5.0',
-                    False,
+                    None,
+                    'dir',
                 ),
                 (
-                    'sandwiches',
+                    'sandwiches.pbj',
-                    'pbj',
-                    b'/usr/share/ansible/collections/ansible_collections/sandwiches/pbj',
-                    mocker.Mock(),
-                    ['1.0.0', '1.5.0'],
                     '1.0.0',
-                    False,
+                    None,
+                    'dir',
                 ),
             ),
             'sandwiches.ham': (
                 (
-                    'sandwiches',
+                    'sandwiches.ham',
-                    'ham',
-                    b'/usr/share/ansible/collections/ansible_collections/sandwiches/ham',
-                    mocker.Mock(),
-                    ['1.0.0'],
                     '1.0.0',
-                    False,
+                    None,
+                    'dir',
                 ),
             ),
         }
 
-        from_path_objects = [CollectionRequirement(*args) for args in collection_args[collection_name]]
+        from_path_objects = [Requirement(*args) for args in collection_args[collection_name]]
-        mocker.patch('ansible.galaxy.collection.CollectionRequirement.from_path', side_effect=from_path_objects)
+        mocker.patch('ansible.cli.galaxy.Requirement.from_dir_path_as_unknown', side_effect=from_path_objects)
 
     return _from_path
 
 
-def test_execute_list_collection_all(mocker, capsys, mock_collection_objects):
+def test_execute_list_collection_all(mocker, capsys, mock_collection_objects, tmp_path_factory):
     """Test listing all collections from multiple paths"""
 
     cliargs()
@@ -143,7 +128,9 @@ def test_execute_list_collection_all(mocker, capsys, mock_collection_objects):
     mocker.patch('os.path.exists', return_value=True)
     mocker.patch('os.path.isdir', return_value=True)
     gc = GalaxyCLI(['ansible-galaxy', 'collection', 'list'])
-    gc.execute_list_collection()
+    tmp_path = tmp_path_factory.mktemp('test-ÅÑŚÌβŁÈ Collections')
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(tmp_path, validate_certs=False)
+    gc.execute_list_collection(artifacts_manager=concrete_artifact_cm)
 
     out, err = capsys.readouterr()
     out_lines = out.splitlines()
@@ -163,7 +150,7 @@ def test_execute_list_collection_all(mocker, capsys, mock_collection_objects):
     assert out_lines[11] == 'sandwiches.pbj 1.0.0  '
 
 
-def test_execute_list_collection_specific(mocker, capsys, mock_collection_objects, mock_from_path):
+def test_execute_list_collection_specific(mocker, capsys, mock_collection_objects, mock_from_path, tmp_path_factory):
     """Test listing a specific collection"""
 
     collection_name = 'sandwiches.ham'
@@ -176,7 +163,9 @@ def test_execute_list_collection_specific(mocker, capsys, mock_collection_object
     mocker.patch('ansible.cli.galaxy._get_collection_widths', return_value=(14, 5))
 
     gc = GalaxyCLI(['ansible-galaxy', 'collection', 'list', collection_name])
-    gc.execute_list_collection()
+    tmp_path = tmp_path_factory.mktemp('test-ÅÑŚÌβŁÈ Collections')
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(tmp_path, validate_certs=False)
+    gc.execute_list_collection(artifacts_manager=concrete_artifact_cm)
 
     out, err = capsys.readouterr()
     out_lines = out.splitlines()
@@ -189,7 +178,7 @@ def test_execute_list_collection_specific(mocker, capsys, mock_collection_object
     assert out_lines[4] == 'sandwiches.ham 1.0.0  '
 
 
-def test_execute_list_collection_specific_duplicate(mocker, capsys, mock_collection_objects, mock_from_path):
+def test_execute_list_collection_specific_duplicate(mocker, capsys, mock_collection_objects, mock_from_path, tmp_path_factory):
     """Test listing a specific collection that exists at multiple paths"""
 
     collection_name = 'sandwiches.pbj'
@@ -201,7 +190,9 @@ def test_execute_list_collection_specific_duplicate(mocker, capsys, mock_collect
     mocker.patch('ansible.galaxy.collection.validate_collection_name', collection_name)
 
     gc = GalaxyCLI(['ansible-galaxy', 'collection', 'list', collection_name])
-    gc.execute_list_collection()
+    tmp_path = tmp_path_factory.mktemp('test-ÅÑŚÌβŁÈ Collections')
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(tmp_path, validate_certs=False)
+    gc.execute_list_collection(artifacts_manager=concrete_artifact_cm)
 
     out, err = capsys.readouterr()
     out_lines = out.splitlines()
@@ -219,7 +210,7 @@ def test_execute_list_collection_specific_duplicate(mocker, capsys, mock_collect
     assert out_lines[9] == 'sandwiches.pbj 1.0.0  '
 
 
-def test_execute_list_collection_specific_invalid_fqcn(mocker):
+def test_execute_list_collection_specific_invalid_fqcn(mocker, tmp_path_factory):
     """Test an invalid fully qualified collection name (FQCN)"""
 
     collection_name = 'no.good.name'
@@ -229,11 +220,13 @@ def test_execute_list_collection_specific_invalid_fqcn(mocker):
     mocker.patch('os.path.isdir', return_value=True)
 
     gc = GalaxyCLI(['ansible-galaxy', 'collection', 'list', collection_name])
+    tmp_path = tmp_path_factory.mktemp('test-ÅÑŚÌβŁÈ Collections')
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(tmp_path, validate_certs=False)
     with pytest.raises(AnsibleError, match='Invalid collection name'):
-        gc.execute_list_collection()
+        gc.execute_list_collection(artifacts_manager=concrete_artifact_cm)
 
 
-def test_execute_list_collection_no_valid_paths(mocker, capsys):
+def test_execute_list_collection_no_valid_paths(mocker, capsys, tmp_path_factory):
     """Test listing collections when no valid paths are given"""
 
     cliargs()
@@ -244,8 +237,11 @@ def test_execute_list_collection_no_valid_paths(mocker, capsys):
     mocker.patch('ansible.cli.galaxy.display.columns', 79)
     gc = GalaxyCLI(['ansible-galaxy', 'collection', 'list'])
 
+    tmp_path = tmp_path_factory.mktemp('test-ÅÑŚÌβŁÈ Collections')
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(tmp_path, validate_certs=False)
+
     with pytest.raises(AnsibleOptionsError, match=r'None of the provided paths were usable.'):
-        gc.execute_list_collection()
+        gc.execute_list_collection(artifacts_manager=concrete_artifact_cm)
 
     out, err = capsys.readouterr()
 
@@ -253,7 +249,7 @@ def test_execute_list_collection_no_valid_paths(mocker, capsys):
     assert 'exists, but it\nis not a directory.' in err
 
 
-def test_execute_list_collection_one_invalid_path(mocker, capsys, mock_collection_objects):
+def test_execute_list_collection_one_invalid_path(mocker, capsys, mock_collection_objects, tmp_path_factory):
     """Test listing all collections when one invalid path is given"""
 
     cliargs()
@@ -263,7 +259,9 @@ def test_execute_list_collection_one_invalid_path(mocker, capsys, mock_collectio
     mocker.patch('ansible.utils.color.ANSIBLE_COLOR', False)
 
     gc = GalaxyCLI(['ansible-galaxy', 'collection', 'list', '-p', 'nope'])
-    gc.execute_list_collection()
+    tmp_path = tmp_path_factory.mktemp('test-ÅÑŚÌβŁÈ Collections')
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(tmp_path, validate_certs=False)
+    gc.execute_list_collection(artifacts_manager=concrete_artifact_cm)
 
     out, err = capsys.readouterr()
     out_lines = out.splitlines()

test/units/cli/galaxy/test_get_collection_widths.py

@@ -8,18 +8,16 @@ __metaclass__ = type
 import pytest
 
 from ansible.cli.galaxy import _get_collection_widths
+from ansible.galaxy.dependency_resolution.dataclasses import Requirement
 
 
 @pytest.fixture
-def collection_objects(mocker):
+def collection_objects():
-    collection_ham = mocker.MagicMock(latest_version='1.5.0')
+    collection_ham = Requirement('sandwiches.ham', '1.5.0', None, 'galaxy')
-    collection_ham.__str__.return_value = 'sandwiches.ham'
 
-    collection_pbj = mocker.MagicMock(latest_version='2.5')
+    collection_pbj = Requirement('sandwiches.pbj', '2.5', None, 'galaxy')
-    collection_pbj.__str__.return_value = 'sandwiches.pbj'
 
-    collection_reuben = mocker.MagicMock(latest_version='4')
+    collection_reuben = Requirement('sandwiches.reuben', '4', None, 'galaxy')
-    collection_reuben.__str__.return_value = 'sandwiches.reuben'
 
     return [collection_ham, collection_pbj, collection_reuben]
 
@@ -29,8 +27,7 @@ def test_get_collection_widths(collection_objects):
 
 
 def test_get_collection_widths_single_collection(mocker):
-    mocked_collection = mocker.MagicMock(latest_version='3.0.0')
+    mocked_collection = Requirement('sandwiches.club', '3.0.0', None, 'galaxy')
-    mocked_collection.__str__.return_value = 'sandwiches.club'
     # Make this look like it is not iterable
     mocker.patch('ansible.cli.galaxy.is_iterable', return_value=False)
 

test/units/cli/test_galaxy.py

@@ -21,6 +21,7 @@ from __future__ import (absolute_import, division, print_function)
 __metaclass__ = type
 
 import ansible
+from io import BytesIO
 import json
 import os
 import pytest
@@ -33,6 +34,7 @@ import yaml
 import ansible.constants as C
 from ansible import context
 from ansible.cli.galaxy import GalaxyCLI
+from ansible.galaxy import collection
 from ansible.galaxy.api import GalaxyAPI
 from ansible.errors import AnsibleError
 from ansible.module_utils._text import to_bytes, to_native, to_text
@@ -630,7 +632,12 @@ def test_invalid_collection_name_init(name):
 ])
 def test_invalid_collection_name_install(name, expected, tmp_path_factory):
     install_path = to_text(tmp_path_factory.mktemp('test-ÅÑŚÌβŁÈ Collections'))
-    expected = "Invalid collection name '%s', name must be in the format <namespace>.<collection>" % expected
+
+    # FIXME: we should add the collection name in the error message
+    # Used to be: expected = "Invalid collection name '%s', name must be in the format <namespace>.<collection>" % expected
+    expected = "Neither the collection requirement entry key 'name', nor 'source' point to a concrete resolvable collection artifact. "
+    expected += r"Also 'name' is not an FQCN\. A valid collection name must be in the format <namespace>\.<collection>\. "
+    expected += r"Please make sure that the namespace and the collection name  contain characters from \[a\-zA\-Z0\-9_\] only\."
 
     gc = GalaxyCLI(args=['ansible-galaxy', 'collection', 'install', name, '-p', os.path.join(install_path, 'install')])
     with pytest.raises(AnsibleError, match=expected):
@@ -758,17 +765,17 @@ def test_collection_install_with_names(collection_install):
         in mock_warning.call_args[0][0]
 
     assert mock_install.call_count == 1
-    assert mock_install.call_args[0][0] == [('namespace.collection', '*', None, None),
+    requirements = [('%s.%s' % (r.namespace, r.name), r.ver, r.src, r.type,) for r in mock_install.call_args[0][0]]
-                                            ('namespace2.collection', '1.0.1', None, None)]
+    assert requirements == [('namespace.collection', '*', None, 'galaxy'),
+                            ('namespace2.collection', '1.0.1', None, 'galaxy')]
     assert mock_install.call_args[0][1] == collection_path
     assert len(mock_install.call_args[0][2]) == 1
     assert mock_install.call_args[0][2][0].api_server == 'https://galaxy.ansible.com'
     assert mock_install.call_args[0][2][0].validate_certs is True
-    assert mock_install.call_args[0][3] is True
+    assert mock_install.call_args[0][3] is False  # ignore_errors
-    assert mock_install.call_args[0][4] is False
+    assert mock_install.call_args[0][4] is False  # no_deps
-    assert mock_install.call_args[0][5] is False
+    assert mock_install.call_args[0][5] is False  # force
-    assert mock_install.call_args[0][6] is False
+    assert mock_install.call_args[0][6] is False  # force_deps
-    assert mock_install.call_args[0][7] is False
 
 
 def test_collection_install_with_requirements_file(collection_install):
@@ -795,17 +802,16 @@ collections:
         in mock_warning.call_args[0][0]
 
     assert mock_install.call_count == 1
-    assert mock_install.call_args[0][0] == [('namespace.coll', '*', None, None),
+    requirements = [('%s.%s' % (r.namespace, r.name), r.ver, r.src, r.type,) for r in mock_install.call_args[0][0]]
-                                            ('namespace2.coll', '>2.0.1', None, None)]
+    assert requirements == [('namespace.coll', '*', None, 'galaxy'),
+                            ('namespace2.coll', '>2.0.1', None, 'galaxy')]
     assert mock_install.call_args[0][1] == collection_path
-    assert len(mock_install.call_args[0][2]) == 1
     assert mock_install.call_args[0][2][0].api_server == 'https://galaxy.ansible.com'
     assert mock_install.call_args[0][2][0].validate_certs is True
-    assert mock_install.call_args[0][3] is True
+    assert mock_install.call_args[0][3] is False  # ignore_errors
-    assert mock_install.call_args[0][4] is False
+    assert mock_install.call_args[0][4] is False  # no_deps
-    assert mock_install.call_args[0][5] is False
+    assert mock_install.call_args[0][5] is False  # force
-    assert mock_install.call_args[0][6] is False
+    assert mock_install.call_args[0][6] is False  # force_deps
-    assert mock_install.call_args[0][7] is False
 
 
 def test_collection_install_with_relative_path(collection_install, monkeypatch):
@@ -829,11 +835,10 @@ def test_collection_install_with_relative_path(collection_install, monkeypatch):
     assert len(mock_install.call_args[0][2]) == 1
     assert mock_install.call_args[0][2][0].api_server == 'https://galaxy.ansible.com'
     assert mock_install.call_args[0][2][0].validate_certs is True
-    assert mock_install.call_args[0][3] is True
+    assert mock_install.call_args[0][3] is False  # ignore_errors
-    assert mock_install.call_args[0][4] is False
+    assert mock_install.call_args[0][4] is False  # no_deps
-    assert mock_install.call_args[0][5] is False
+    assert mock_install.call_args[0][5] is False  # force
-    assert mock_install.call_args[0][6] is False
+    assert mock_install.call_args[0][6] is False  # force_deps
-    assert mock_install.call_args[0][7] is False
 
     assert mock_req.call_count == 1
     assert mock_req.call_args[0][0] == os.path.abspath(requirements_file)
@@ -860,11 +865,10 @@ def test_collection_install_with_unexpanded_path(collection_install, monkeypatch
     assert len(mock_install.call_args[0][2]) == 1
     assert mock_install.call_args[0][2][0].api_server == 'https://galaxy.ansible.com'
     assert mock_install.call_args[0][2][0].validate_certs is True
-    assert mock_install.call_args[0][3] is True
+    assert mock_install.call_args[0][3] is False  # ignore_errors
-    assert mock_install.call_args[0][4] is False
+    assert mock_install.call_args[0][4] is False  # no_deps
-    assert mock_install.call_args[0][5] is False
+    assert mock_install.call_args[0][5] is False  # force
-    assert mock_install.call_args[0][6] is False
+    assert mock_install.call_args[0][6] is False  # force_deps
-    assert mock_install.call_args[0][7] is False
 
     assert mock_req.call_count == 1
     assert mock_req.call_args[0][0] == os.path.expanduser(os.path.expandvars(requirements_file))
@@ -882,22 +886,28 @@ def test_collection_install_in_collection_dir(collection_install, monkeypatch):
     assert mock_warning.call_count == 0
 
     assert mock_install.call_count == 1
-    assert mock_install.call_args[0][0] == [('namespace.collection', '*', None, None),
+    requirements = [('%s.%s' % (r.namespace, r.name), r.ver, r.src, r.type,) for r in mock_install.call_args[0][0]]
-                                            ('namespace2.collection', '1.0.1', None, None)]
+    assert requirements == [('namespace.collection', '*', None, 'galaxy'),
+                            ('namespace2.collection', '1.0.1', None, 'galaxy')]
     assert mock_install.call_args[0][1] == os.path.join(collections_path, 'ansible_collections')
     assert len(mock_install.call_args[0][2]) == 1
     assert mock_install.call_args[0][2][0].api_server == 'https://galaxy.ansible.com'
     assert mock_install.call_args[0][2][0].validate_certs is True
-    assert mock_install.call_args[0][3] is True
+    assert mock_install.call_args[0][3] is False  # ignore_errors
-    assert mock_install.call_args[0][4] is False
+    assert mock_install.call_args[0][4] is False  # no_deps
-    assert mock_install.call_args[0][5] is False
+    assert mock_install.call_args[0][5] is False  # force
-    assert mock_install.call_args[0][6] is False
+    assert mock_install.call_args[0][6] is False  # force_deps
-    assert mock_install.call_args[0][7] is False
 
 
-def test_collection_install_with_url(collection_install):
+def test_collection_install_with_url(monkeypatch, collection_install):
     mock_install, dummy, output_dir = collection_install
 
+    mock_open = MagicMock(return_value=BytesIO())
+    monkeypatch.setattr(collection.concrete_artifact_manager, 'open_url', mock_open)
+
+    mock_metadata = MagicMock(return_value={'namespace': 'foo', 'name': 'bar', 'version': 'v1.0.0'})
+    monkeypatch.setattr(collection.concrete_artifact_manager, '_get_meta_from_tar', mock_metadata)
+
     galaxy_args = ['ansible-galaxy', 'collection', 'install', 'https://foo/bar/foo-bar-v1.0.0.tar.gz',
                    '--collections-path', output_dir]
     GalaxyCLI(args=galaxy_args).run()
@@ -906,16 +916,16 @@ def test_collection_install_with_url(collection_install):
     assert os.path.isdir(collection_path)
 
     assert mock_install.call_count == 1
-    assert mock_install.call_args[0][0] == [('https://foo/bar/foo-bar-v1.0.0.tar.gz', '*', None, None)]
+    requirements = [('%s.%s' % (r.namespace, r.name), r.ver, r.src, r.type,) for r in mock_install.call_args[0][0]]
+    assert requirements == [('foo.bar', 'v1.0.0', 'https://foo/bar/foo-bar-v1.0.0.tar.gz', 'url')]
     assert mock_install.call_args[0][1] == collection_path
     assert len(mock_install.call_args[0][2]) == 1
     assert mock_install.call_args[0][2][0].api_server == 'https://galaxy.ansible.com'
     assert mock_install.call_args[0][2][0].validate_certs is True
-    assert mock_install.call_args[0][3] is True
+    assert mock_install.call_args[0][3] is False  # ignore_errors
-    assert mock_install.call_args[0][4] is False
+    assert mock_install.call_args[0][4] is False  # no_deps
-    assert mock_install.call_args[0][5] is False
+    assert mock_install.call_args[0][5] is False  # force
-    assert mock_install.call_args[0][6] is False
+    assert mock_install.call_args[0][6] is False  # force_deps
-    assert mock_install.call_args[0][7] is False
 
 
 def test_collection_install_name_and_requirements_fail(collection_install):
@@ -951,17 +961,17 @@ def test_collection_install_path_with_ansible_collections(collection_install):
         % collection_path in mock_warning.call_args[0][0]
 
     assert mock_install.call_count == 1
-    assert mock_install.call_args[0][0] == [('namespace.collection', '*', None, None),
+    requirements = [('%s.%s' % (r.namespace, r.name), r.ver, r.src, r.type,) for r in mock_install.call_args[0][0]]
-                                            ('namespace2.collection', '1.0.1', None, None)]
+    assert requirements == [('namespace.collection', '*', None, 'galaxy'),
+                            ('namespace2.collection', '1.0.1', None, 'galaxy')]
     assert mock_install.call_args[0][1] == collection_path
     assert len(mock_install.call_args[0][2]) == 1
     assert mock_install.call_args[0][2][0].api_server == 'https://galaxy.ansible.com'
     assert mock_install.call_args[0][2][0].validate_certs is True
-    assert mock_install.call_args[0][3] is True
+    assert mock_install.call_args[0][3] is False  # ignore_errors
-    assert mock_install.call_args[0][4] is False
+    assert mock_install.call_args[0][4] is False  # no_deps
-    assert mock_install.call_args[0][5] is False
+    assert mock_install.call_args[0][5] is False  # force
-    assert mock_install.call_args[0][6] is False
+    assert mock_install.call_args[0][6] is False  # force_deps
-    assert mock_install.call_args[0][7] is False
 
 
 def test_collection_install_ignore_certs(collection_install):
@@ -981,7 +991,8 @@ def test_collection_install_force(collection_install):
                    '--force']
     GalaxyCLI(args=galaxy_args).run()
 
-    assert mock_install.call_args[0][6] is True
+    # mock_install args: collections, output_path, apis, ignore_errors, no_deps, force, force_deps
+    assert mock_install.call_args[0][5] is True
 
 
 def test_collection_install_force_deps(collection_install):
@@ -991,7 +1002,8 @@ def test_collection_install_force_deps(collection_install):
                    '--force-with-deps']
     GalaxyCLI(args=galaxy_args).run()
 
-    assert mock_install.call_args[0][7] is True
+    # mock_install args: collections, output_path, apis, ignore_errors, no_deps, force, force_deps
+    assert mock_install.call_args[0][6] is True
 
 
 def test_collection_install_no_deps(collection_install):
@@ -1001,7 +1013,8 @@ def test_collection_install_no_deps(collection_install):
                    '--no-deps']
     GalaxyCLI(args=galaxy_args).run()
 
-    assert mock_install.call_args[0][5] is True
+    # mock_install args: collections, output_path, apis, ignore_errors, no_deps, force, force_deps
+    assert mock_install.call_args[0][4] is True
 
 
 def test_collection_install_ignore(collection_install):
@@ -1011,7 +1024,8 @@ def test_collection_install_ignore(collection_install):
                    '--ignore-errors']
     GalaxyCLI(args=galaxy_args).run()
 
-    assert mock_install.call_args[0][4] is True
+    # mock_install args: collections, output_path, apis, ignore_errors, no_deps, force, force_deps
+    assert mock_install.call_args[0][3] is True
 
 
 def test_collection_install_custom_server(collection_install):
@@ -1080,7 +1094,13 @@ collections:
 - version: 1.0.0
 '''], indirect=True)
 def test_parse_requirements_without_mandatory_name_key(requirements_cli, requirements_file):
-    expected = "Collections requirement entry should contain the key name."
+    # Used to be "Collections requirement entry should contain the key name."
+    # Should we check that either source or name is provided before using the dep resolver?
+
+    expected = "Neither the collection requirement entry key 'name', nor 'source' point to a concrete resolvable collection artifact. "
+    expected += r"Also 'name' is not an FQCN\. A valid collection name must be in the format <namespace>\.<collection>\. "
+    expected += r"Please make sure that the namespace and the collection name  contain characters from \[a\-zA\-Z0\-9_\] only\."
+
     with pytest.raises(AnsibleError, match=expected):
         requirements_cli._parse_requirements_file(requirements_file)
 
@@ -1097,9 +1117,10 @@ collections:
 def test_parse_requirements(requirements_cli, requirements_file):
     expected = {
         'roles': [],
-        'collections': [('namespace.collection1', '*', None, None), ('namespace.collection2', '*', None, None)]
+        'collections': [('namespace.collection1', '*', None, 'galaxy'), ('namespace.collection2', '*', None, 'galaxy')]
     }
     actual = requirements_cli._parse_requirements_file(requirements_file)
+    actual['collections'] = [('%s.%s' % (r.namespace, r.name), r.ver, r.src, r.type,) for r in actual.get('collections', [])]
 
     assert actual == expected
 
@@ -1112,19 +1133,15 @@ collections:
 - namespace.collection2'''], indirect=True)
 def test_parse_requirements_with_extra_info(requirements_cli, requirements_file):
     actual = requirements_cli._parse_requirements_file(requirements_file)
+    actual['collections'] = [('%s.%s' % (r.namespace, r.name), r.ver, r.src, r.type,) for r in actual.get('collections', [])]
 
     assert len(actual['roles']) == 0
     assert len(actual['collections']) == 2
     assert actual['collections'][0][0] == 'namespace.collection1'
     assert actual['collections'][0][1] == '>=1.0.0,<=2.0.0'
     assert actual['collections'][0][2].api_server == 'https://galaxy-dev.ansible.com'
-    assert actual['collections'][0][2].name == 'explicit_requirement_namespace.collection1'
-    assert actual['collections'][0][2].token is None
-    assert actual['collections'][0][2].username is None
-    assert actual['collections'][0][2].password is None
-    assert actual['collections'][0][2].validate_certs is True
 
-    assert actual['collections'][1] == ('namespace.collection2', '*', None, None)
+    assert actual['collections'][1] == ('namespace.collection2', '*', None, 'galaxy')
 
 
 @pytest.mark.parametrize('requirements_file', ['''
@@ -1139,6 +1156,7 @@ collections:
 '''], indirect=True)
 def test_parse_requirements_with_roles_and_collections(requirements_cli, requirements_file):
     actual = requirements_cli._parse_requirements_file(requirements_file)
+    actual['collections'] = [('%s.%s' % (r.namespace, r.name), r.ver, r.src, r.type,) for r in actual.get('collections', [])]
 
     assert len(actual['roles']) == 3
     assert actual['roles'][0].name == 'username.role_name'
@@ -1147,7 +1165,7 @@ def test_parse_requirements_with_roles_and_collections(requirements_cli, require
     assert actual['roles'][2].src == 'ssh://github.com/user/repo'
 
     assert len(actual['collections']) == 1
-    assert actual['collections'][0] == ('namespace.collection2', '*', None, None)
+    assert actual['collections'][0] == ('namespace.collection2', '*', None, 'galaxy')
 
 
 @pytest.mark.parametrize('requirements_file', ['''
@@ -1163,18 +1181,19 @@ def test_parse_requirements_with_collection_source(requirements_cli, requirement
     requirements_cli.api_servers.append(galaxy_api)
 
     actual = requirements_cli._parse_requirements_file(requirements_file)
+    actual['collections'] = [('%s.%s' % (r.namespace, r.name), r.ver, r.src, r.type,) for r in actual.get('collections', [])]
 
     assert actual['roles'] == []
     assert len(actual['collections']) == 3
-    assert actual['collections'][0] == ('namespace.collection', '*', None, None)
+    assert actual['collections'][0] == ('namespace.collection', '*', None, 'galaxy')
 
     assert actual['collections'][1][0] == 'namespace2.collection2'
     assert actual['collections'][1][1] == '*'
     assert actual['collections'][1][2].api_server == 'https://galaxy-dev.ansible.com/'
-    assert actual['collections'][1][2].name == 'explicit_requirement_namespace2.collection2'
-    assert actual['collections'][1][2].token is None
 
-    assert actual['collections'][2] == ('namespace3.collection3', '*', galaxy_api, None)
+    assert actual['collections'][2][0] == 'namespace3.collection3'
+    assert actual['collections'][2][1] == '*'
+    assert actual['collections'][2][2].api_server == 'https://config-server'
 
 
 @pytest.mark.parametrize('requirements_file', ['''
@@ -1230,7 +1249,8 @@ def test_install_implicit_role_with_collections(requirements_file, monkeypatch):
     cli.run()
 
     assert mock_collection_install.call_count == 1
-    assert mock_collection_install.call_args[0][0] == [('namespace.name', '*', None, None)]
+    requirements = [('%s.%s' % (r.namespace, r.name), r.ver, r.src, r.type,) for r in mock_collection_install.call_args[0][0]]
+    assert requirements == [('namespace.name', '*', None, 'galaxy')]
     assert mock_collection_install.call_args[0][1] == cli._get_default_collection_path()
 
     assert mock_role_install.call_count == 1
@@ -1328,8 +1348,8 @@ def test_install_collection_with_roles(requirements_file, monkeypatch):
     cli.run()
 
     assert mock_collection_install.call_count == 1
-    assert mock_collection_install.call_args[0][0] == [('namespace.name', '*', None, None)]
+    requirements = [('%s.%s' % (r.namespace, r.name), r.ver, r.src, r.type,) for r in mock_collection_install.call_args[0][0]]
-    assert mock_collection_install.call_args[0][1] == cli._get_default_collection_path()
+    assert requirements == [('namespace.name', '*', None, 'galaxy')]
 
     assert mock_role_install.call_count == 0
 

test/units/galaxy/test_collection.py

@@ -56,7 +56,7 @@ def collection_input(tmp_path_factory):
 def collection_artifact(monkeypatch, tmp_path_factory):
     ''' Creates a temp collection artifact and mocked open_url instance for publishing tests '''
     mock_open = MagicMock()
-    monkeypatch.setattr(collection, 'open_url', mock_open)
+    monkeypatch.setattr(collection.concrete_artifact_manager, 'open_url', mock_open)
 
     mock_uuid = MagicMock()
     mock_uuid.return_value.hex = 'uuid'
@@ -76,13 +76,13 @@ def collection_artifact(monkeypatch, tmp_path_factory):
 
 
 @pytest.fixture()
-def galaxy_yml(request, tmp_path_factory):
+def galaxy_yml_dir(request, tmp_path_factory):
     b_test_dir = to_bytes(tmp_path_factory.mktemp('test-ÅÑŚÌβŁÈ Collections'))
     b_galaxy_yml = os.path.join(b_test_dir, b'galaxy.yml')
     with open(b_galaxy_yml, 'wb') as galaxy_obj:
         galaxy_obj.write(to_bytes(request.param))
 
-    yield b_galaxy_yml
+    yield b_test_dir
 
 
 @pytest.fixture()
@@ -198,31 +198,12 @@ def manifest(manifest_info):
             yield fake_file, sha256(b_data).hexdigest()
 
 
-@pytest.fixture()
-def mock_collection(galaxy_server):
-    def create_mock_collection(namespace='ansible_namespace', name='collection', version='0.1.0', local=True, local_installed=True):
-        b_path = None
-        force = False
-
-        if local:
-            mock_collection = collection.CollectionRequirement(namespace, name, b_path, galaxy_server, [version], version, force, skip=local_installed)
-        else:
-            download_url = 'https://galaxy.ansible.com/download/{0}-{1}-{2}.tar.gz'.format(namespace, name, version)
-            digest = '19415a6a6df831df61cffde4a09d1d89ac8d8ca5c0586e85bea0b106d6dff29a'
-            dependencies = {}
-            metadata = api.CollectionVersionMetadata(namespace, name, version, download_url, digest, dependencies)
-            mock_collection = collection.CollectionRequirement(namespace, name, b_path, galaxy_server, [version], version, force, metadata=metadata)
-
-        return mock_collection
-    return create_mock_collection
-
-
 def test_build_collection_no_galaxy_yaml():
     fake_path = u'/fake/ÅÑŚÌβŁÈ/path'
     expected = to_native("The collection galaxy.yml path '%s/galaxy.yml' does not exist." % fake_path)
 
     with pytest.raises(AnsibleError, match=expected):
-        collection.build_collection(fake_path, 'output', False)
+        collection.build_collection(fake_path, u'output', False)
 
 
 def test_build_existing_output_file(collection_input):
@@ -234,7 +215,7 @@ def test_build_existing_output_file(collection_input):
     expected = "The output collection artifact '%s' already exists, but is a directory - aborting" \
                % to_native(existing_output_dir)
     with pytest.raises(AnsibleError, match=expected):
-        collection.build_collection(input_dir, output_dir, False)
+        collection.build_collection(to_text(input_dir, errors='surrogate_or_strict'), to_text(output_dir, errors='surrogate_or_strict'), False)
 
 
 def test_build_existing_output_without_force(collection_input):
@@ -248,7 +229,7 @@ def test_build_existing_output_without_force(collection_input):
     expected = "The file '%s' already exists. You can use --force to re-create the collection artifact." \
                % to_native(existing_output)
     with pytest.raises(AnsibleError, match=expected):
-        collection.build_collection(input_dir, output_dir, False)
+        collection.build_collection(to_text(input_dir, errors='surrogate_or_strict'), to_text(output_dir, errors='surrogate_or_strict'), False)
 
 
 def test_build_existing_output_with_force(collection_input):
@@ -259,55 +240,57 @@ def test_build_existing_output_with_force(collection_input):
         out_file.write("random garbage")
         out_file.flush()
 
-    collection.build_collection(input_dir, output_dir, True)
+    collection.build_collection(to_text(input_dir, errors='surrogate_or_strict'), to_text(output_dir, errors='surrogate_or_strict'), True)
 
     # Verify the file was replaced with an actual tar file
     assert tarfile.is_tarfile(existing_output)
 
 
-@pytest.mark.parametrize('galaxy_yml', [b'namespace: value: broken'], indirect=True)
+@pytest.mark.parametrize('galaxy_yml_dir', [b'namespace: value: broken'], indirect=True)
-def test_invalid_yaml_galaxy_file(galaxy_yml):
+def test_invalid_yaml_galaxy_file(galaxy_yml_dir):
-    expected = to_native(b"Failed to parse the galaxy.yml at '%s' with the following error:" % galaxy_yml)
+    galaxy_file = os.path.join(galaxy_yml_dir, b'galaxy.yml')
+    expected = to_native(b"Failed to parse the galaxy.yml at '%s' with the following error:" % galaxy_file)
 
     with pytest.raises(AnsibleError, match=expected):
-        collection._get_galaxy_yml(galaxy_yml)
+        collection.concrete_artifact_manager._get_meta_from_src_dir(galaxy_yml_dir)
 
 
-@pytest.mark.parametrize('galaxy_yml', [b'namespace: test_namespace'], indirect=True)
+@pytest.mark.parametrize('galaxy_yml_dir', [b'namespace: test_namespace'], indirect=True)
-def test_missing_required_galaxy_key(galaxy_yml):
+def test_missing_required_galaxy_key(galaxy_yml_dir):
+    galaxy_file = os.path.join(galaxy_yml_dir, b'galaxy.yml')
     expected = "The collection galaxy.yml at '%s' is missing the following mandatory keys: authors, name, " \
-               "readme, version" % to_native(galaxy_yml)
+               "readme, version" % to_native(galaxy_file)
 
     with pytest.raises(AnsibleError, match=expected):
-        collection._get_galaxy_yml(galaxy_yml)
+        collection.concrete_artifact_manager._get_meta_from_src_dir(galaxy_yml_dir)
 
 
-@pytest.mark.parametrize('galaxy_yml', [b"""
+@pytest.mark.parametrize('galaxy_yml_dir', [b"""
 namespace: namespace
 name: collection
 authors: Jordan
 version: 0.1.0
 readme: README.md
 invalid: value"""], indirect=True)
-def test_warning_extra_keys(galaxy_yml, monkeypatch):
+def test_warning_extra_keys(galaxy_yml_dir, monkeypatch):
     display_mock = MagicMock()
     monkeypatch.setattr(Display, 'warning', display_mock)
 
-    collection._get_galaxy_yml(galaxy_yml)
+    collection.concrete_artifact_manager._get_meta_from_src_dir(galaxy_yml_dir)
 
     assert display_mock.call_count == 1
-    assert display_mock.call_args[0][0] == "Found unknown keys in collection galaxy.yml at '%s': invalid"\
+    assert display_mock.call_args[0][0] == "Found unknown keys in collection galaxy.yml at '%s/galaxy.yml': invalid"\
-        % to_text(galaxy_yml)
+        % to_text(galaxy_yml_dir)
 
 
-@pytest.mark.parametrize('galaxy_yml', [b"""
+@pytest.mark.parametrize('galaxy_yml_dir', [b"""
 namespace: namespace
 name: collection
 authors: Jordan
 version: 0.1.0
 readme: README.md"""], indirect=True)
-def test_defaults_galaxy_yml(galaxy_yml):
+def test_defaults_galaxy_yml(galaxy_yml_dir):
-    actual = collection._get_galaxy_yml(galaxy_yml)
+    actual = collection.concrete_artifact_manager._get_meta_from_src_dir(galaxy_yml_dir)
 
     assert actual['namespace'] == 'namespace'
     assert actual['name'] == 'collection'
@@ -321,10 +304,10 @@ def test_defaults_galaxy_yml(galaxy_yml):
     assert actual['issues'] is None
     assert actual['tags'] == []
     assert actual['dependencies'] == {}
-    assert actual['license_ids'] == []
+    assert actual['license'] == []
 
 
-@pytest.mark.parametrize('galaxy_yml', [(b"""
+@pytest.mark.parametrize('galaxy_yml_dir', [(b"""
 namespace: namespace
 name: collection
 authors: Jordan
@@ -338,9 +321,9 @@ version: 0.1.0
 readme: README.md
 license:
 - MIT""")], indirect=True)
-def test_galaxy_yml_list_value(galaxy_yml):
+def test_galaxy_yml_list_value(galaxy_yml_dir):
-    actual = collection._get_galaxy_yml(galaxy_yml)
+    actual = collection.concrete_artifact_manager._get_meta_from_src_dir(galaxy_yml_dir)
-    assert actual['license_ids'] == ['MIT']
+    assert actual['license'] == ['MIT']
 
 
 def test_build_ignore_files_and_folders(collection_input, monkeypatch):
@@ -529,7 +512,7 @@ def test_build_with_symlink_inside_collection(collection_input):
     os.symlink(roles_target, roles_link)
     os.symlink(os.path.join(input_dir, 'README.md'), file_link)
 
-    collection.build_collection(input_dir, output_dir, False)
+    collection.build_collection(to_text(input_dir, errors='surrogate_or_strict'), to_text(output_dir, errors='surrogate_or_strict'), False)
 
     output_artifact = os.path.join(output_dir, 'ansible_namespace-collection-0.1.0.tar.gz')
     assert tarfile.is_tarfile(output_artifact)
@@ -603,6 +586,7 @@ def test_publish_with_wait(galaxy_server, collection_artifact, monkeypatch):
 
 def test_find_existing_collections(tmp_path_factory, monkeypatch):
     test_dir = to_text(tmp_path_factory.mktemp('test-ÅÑŚÌβŁÈ Collections'))
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(test_dir, validate_certs=False)
     collection1 = os.path.join(test_dir, 'namespace1', 'collection1')
     collection2 = os.path.join(test_dir, 'namespace2', 'collection2')
     fake_collection1 = os.path.join(test_dir, 'namespace3', 'collection3')
@@ -631,32 +615,24 @@ def test_find_existing_collections(tmp_path_factory, monkeypatch):
     mock_warning = MagicMock()
     monkeypatch.setattr(Display, 'warning', mock_warning)
 
-    actual = collection.find_existing_collections(test_dir)
+    actual = list(collection.find_existing_collections(test_dir, artifacts_manager=concrete_artifact_cm))
 
     assert len(actual) == 2
     for actual_collection in actual:
-        assert actual_collection.skip is True
+        if '%s.%s' % (actual_collection.namespace, actual_collection.name) == 'namespace1.collection1':
-
-        if str(actual_collection) == 'namespace1.collection1':
             assert actual_collection.namespace == 'namespace1'
             assert actual_collection.name == 'collection1'
-            assert actual_collection.b_path == to_bytes(collection1)
+            assert actual_collection.ver == '1.2.3'
-            assert actual_collection.api is None
+            assert to_text(actual_collection.src) == collection1
-            assert actual_collection.versions == set(['1.2.3'])
-            assert actual_collection.latest_version == '1.2.3'
-            assert actual_collection.dependencies == {}
         else:
             assert actual_collection.namespace == 'namespace2'
             assert actual_collection.name == 'collection2'
-            assert actual_collection.b_path == to_bytes(collection2)
+            assert actual_collection.ver == '*'
-            assert actual_collection.api is None
+            assert to_text(actual_collection.src) == collection2
-            assert actual_collection.versions == set(['*'])
-            assert actual_collection.latest_version == '*'
-            assert actual_collection.dependencies == {}
 
     assert mock_warning.call_count == 1
-    assert mock_warning.mock_calls[0][1][0] == "Collection at '%s' does not have a MANIFEST.json file, cannot " \
+    assert mock_warning.mock_calls[0][1][0] == "Collection at '%s' does not have a MANIFEST.json file, nor has it galaxy.yml: " \
-                                               "detect version." % to_text(collection2)
+                                               "cannot detect version." % to_text(collection2)
 
 
 def test_download_file(tmp_path_factory, monkeypatch):
@@ -668,9 +644,9 @@ def test_download_file(tmp_path_factory, monkeypatch):
 
     mock_open = MagicMock()
     mock_open.return_value = BytesIO(data)
-    monkeypatch.setattr(collection, 'open_url', mock_open)
+    monkeypatch.setattr(collection.concrete_artifact_manager, 'open_url', mock_open)
 
-    expected = os.path.join(temp_dir, b'file')
+    expected = temp_dir
     actual = collection._download_file('http://google.com/file', temp_dir, sha256_hash.hexdigest(), True)
 
     assert actual.startswith(expected)
@@ -689,7 +665,7 @@ def test_download_file_hash_mismatch(tmp_path_factory, monkeypatch):
 
     mock_open = MagicMock()
     mock_open.return_value = BytesIO(data)
-    monkeypatch.setattr(collection, 'open_url', mock_open)
+    monkeypatch.setattr(collection.concrete_artifact_manager, 'open_url', mock_open)
 
     expected = "Mismatch artifact hash with downloaded file"
     with pytest.raises(AnsibleError, match=expected):
@@ -772,7 +748,8 @@ def test_require_one_of_collections_requirements_with_collections():
 
     requirements = cli._require_one_of_collections_requirements(collections, '')['collections']
 
-    assert requirements == [('namespace1.collection1', '*', None, None), ('namespace2.collection1', '1.0.0', None, None)]
+    req_tuples = [('%s.%s' % (req.namespace, req.name), req.ver, req.src, req.type,) for req in requirements]
+    assert req_tuples == [('namespace1.collection1', '*', None, 'galaxy'), ('namespace2.collection1', '1.0.0', None, 'galaxy')]
 
 
 @patch('ansible.cli.galaxy.GalaxyCLI._parse_requirements_file')
@@ -821,13 +798,13 @@ def test_execute_verify_with_defaults(mock_verify_collections):
 
     assert mock_verify_collections.call_count == 1
 
-    requirements, search_paths, galaxy_apis, validate, ignore_errors = mock_verify_collections.call_args[0]
+    print("Call args {0}".format(mock_verify_collections.call_args[0]))
+    requirements, search_paths, galaxy_apis, ignore_errors = mock_verify_collections.call_args[0]
 
-    assert requirements == [('namespace.collection', '1.0.4', None, None)]
+    assert [('%s.%s' % (r.namespace, r.name), r.ver, r.src, r.type) for r in requirements] == [('namespace.collection', '1.0.4', None, 'galaxy')]
     for install_path in search_paths:
         assert install_path.endswith('ansible_collections')
     assert galaxy_apis[0].api_server == 'https://galaxy.ansible.com'
-    assert validate is True
     assert ignore_errors is False
 
 
@@ -840,13 +817,12 @@ def test_execute_verify(mock_verify_collections):
 
     assert mock_verify_collections.call_count == 1
 
-    requirements, search_paths, galaxy_apis, validate, ignore_errors = mock_verify_collections.call_args[0]
+    requirements, search_paths, galaxy_apis, ignore_errors = mock_verify_collections.call_args[0]
 
-    assert requirements == [('namespace.collection', '1.0.4', None, None)]
+    assert [('%s.%s' % (r.namespace, r.name), r.ver, r.src, r.type) for r in requirements] == [('namespace.collection', '1.0.4', None, 'galaxy')]
     for install_path in search_paths:
         assert install_path.endswith('ansible_collections')
     assert galaxy_apis[0].api_server == 'http://galaxy-dev.com'
-    assert validate is False
     assert ignore_errors is True
 
 
@@ -863,8 +839,7 @@ def test_verify_file_hash_deleted_file(manifest_info):
 
     with patch.object(builtins, 'open', mock_open(read_data=data)) as m:
         with patch.object(collection.os.path, 'isfile', MagicMock(return_value=False)) as mock_isfile:
-            collection_req = collection.CollectionRequirement(namespace, name, './', server, [version], version, False)
+            collection._verify_file_hash(b'path/', 'file', digest, error_queue)
-            collection_req._verify_file_hash(b'path/', 'file', digest, error_queue)
 
             assert mock_isfile.called_once
 
@@ -887,8 +862,7 @@ def test_verify_file_hash_matching_hash(manifest_info):
 
     with patch.object(builtins, 'open', mock_open(read_data=data)) as m:
         with patch.object(collection.os.path, 'isfile', MagicMock(return_value=True)) as mock_isfile:
-            collection_req = collection.CollectionRequirement(namespace, name, './', server, [version], version, False)
+            collection._verify_file_hash(b'path/', 'file', digest, error_queue)
-            collection_req._verify_file_hash(b'path/', 'file', digest, error_queue)
 
             assert mock_isfile.called_once
 
@@ -910,8 +884,7 @@ def test_verify_file_hash_mismatching_hash(manifest_info):
 
     with patch.object(builtins, 'open', mock_open(read_data=data)) as m:
         with patch.object(collection.os.path, 'isfile', MagicMock(return_value=True)) as mock_isfile:
-            collection_req = collection.CollectionRequirement(namespace, name, './', server, [version], version, False)
+            collection._verify_file_hash(b'path/', 'file', different_digest, error_queue)
-            collection_req._verify_file_hash(b'path/', 'file', different_digest, error_queue)
 
             assert mock_isfile.called_once
 
@@ -972,355 +945,3 @@ def test_get_json_from_tar_file(tmp_tarfile):
     data = collection._get_json_from_tar_file(tfile.name, 'MANIFEST.json')
 
     assert isinstance(data, dict)
-
-
-def test_verify_collection_not_installed(mock_collection):
-
-    local_collection = mock_collection(local_installed=False)
-    remote_collection = mock_collection(local=False)
-
-    with patch.object(collection.display, 'display') as mocked_display:
-        local_collection.verify(remote_collection, './', './')
-
-        assert mocked_display.called
-        assert mocked_display.call_args[0][0] == "'%s.%s' has not been installed, nothing to verify" % (local_collection.namespace, local_collection.name)
-
-
-def test_verify_successful_debug_info(monkeypatch, mock_collection):
-    local_collection = mock_collection()
-    remote_collection = mock_collection(local=False)
-
-    monkeypatch.setattr(collection, '_get_tar_file_hash', MagicMock())
-    monkeypatch.setattr(collection.CollectionRequirement, '_verify_file_hash', MagicMock())
-    monkeypatch.setattr(collection, '_get_json_from_tar_file', MagicMock())
-
-    with patch.object(collection.display, 'vvv') as mock_display:
-        local_collection.verify(remote_collection, './', './')
-
-        namespace = local_collection.namespace
-        name = local_collection.name
-        version = local_collection.latest_version
-
-        assert mock_display.call_count == 4
-        assert mock_display.call_args_list[0][0][0] == "Verifying '%s.%s:%s'." % (namespace, name, version)
-        assert mock_display.call_args_list[1][0][0] == "Installed collection found at './%s/%s'" % (namespace, name)
-        located = "Remote collection found at 'https://galaxy.ansible.com/download/%s-%s-%s.tar.gz'" % (namespace, name, version)
-        assert mock_display.call_args_list[2][0][0] == located
-        verified = "Successfully verified that checksums for '%s.%s:%s' match the remote collection" % (namespace, name, version)
-        assert mock_display.call_args_list[3][0][0] == verified
-
-
-def test_verify_different_versions(mock_collection):
-
-    local_collection = mock_collection(version='0.1.0')
-    remote_collection = mock_collection(local=False, version='3.0.0')
-
-    with patch.object(collection.display, 'display') as mock_display:
-        local_collection.verify(remote_collection, './', './')
-
-        namespace = local_collection.namespace
-        name = local_collection.name
-        installed_version = local_collection.latest_version
-        compared_version = remote_collection.latest_version
-
-        msg = "%s.%s has the version '%s' but is being compared to '%s'" % (namespace, name, installed_version, compared_version)
-
-        assert mock_display.call_count == 1
-        assert mock_display.call_args[0][0] == msg
-
-
-@patch.object(builtins, 'open', mock_open())
-def test_verify_modified_manifest(monkeypatch, mock_collection, manifest_info):
-    local_collection = mock_collection()
-    remote_collection = mock_collection(local=False)
-
-    monkeypatch.setattr(collection, '_get_tar_file_hash', MagicMock(side_effect=['manifest_checksum']))
-    monkeypatch.setattr(collection, '_consume_file', MagicMock(side_effect=['manifest_checksum_modified', 'files_manifest_checksum']))
-    monkeypatch.setattr(collection, '_get_json_from_tar_file', MagicMock(side_effect=[manifest_info, {'files': []}]))
-    monkeypatch.setattr(collection.os.path, 'isfile', MagicMock(return_value=True))
-
-    with patch.object(collection.display, 'display') as mock_display:
-        with patch.object(collection.display, 'vvv') as mock_debug:
-            local_collection.verify(remote_collection, './', './')
-
-            namespace = local_collection.namespace
-            name = local_collection.name
-
-            assert mock_display.call_count == 3
-            assert mock_display.call_args_list[0][0][0] == 'Collection %s.%s contains modified content in the following files:' % (namespace, name)
-            assert mock_display.call_args_list[1][0][0] == '%s.%s' % (namespace, name)
-            assert mock_display.call_args_list[2][0][0] == '    MANIFEST.json'
-
-            # The -vvv output should show details (the checksums do not match)
-            assert mock_debug.call_count == 5
-            assert mock_debug.call_args_list[-1][0][0] == '    Expected: manifest_checksum\n    Found: manifest_checksum_modified'
-
-
-@patch.object(builtins, 'open', mock_open())
-def test_verify_modified_files_manifest(monkeypatch, mock_collection, manifest_info):
-    local_collection = mock_collection()
-    remote_collection = mock_collection(local=False)
-
-    monkeypatch.setattr(collection, '_get_tar_file_hash', MagicMock(side_effect=['manifest_checksum']))
-    monkeypatch.setattr(collection, '_consume_file', MagicMock(side_effect=['manifest_checksum', 'files_manifest_checksum_modified']))
-    monkeypatch.setattr(collection, '_get_json_from_tar_file', MagicMock(side_effect=[manifest_info, {'files': []}]))
-    monkeypatch.setattr(collection.os.path, 'isfile', MagicMock(return_value=True))
-
-    with patch.object(collection.display, 'display') as mock_display:
-        with patch.object(collection.display, 'vvv') as mock_debug:
-            local_collection.verify(remote_collection, './', './')
-
-            namespace = local_collection.namespace
-            name = local_collection.name
-
-            assert mock_display.call_count == 3
-            assert mock_display.call_args_list[0][0][0] == 'Collection %s.%s contains modified content in the following files:' % (namespace, name)
-            assert mock_display.call_args_list[1][0][0] == '%s.%s' % (namespace, name)
-            assert mock_display.call_args_list[2][0][0] == '    FILES.json'
-
-            # The -vvv output should show details (the checksums do not match)
-            assert mock_debug.call_count == 5
-            assert mock_debug.call_args_list[-1][0][0] == '    Expected: files_manifest_checksum\n    Found: files_manifest_checksum_modified'
-
-
-@patch.object(builtins, 'open', mock_open())
-def test_verify_modified_files(monkeypatch, mock_collection, manifest_info, files_manifest_info):
-
-    local_collection = mock_collection()
-    remote_collection = mock_collection(local=False)
-
-    monkeypatch.setattr(collection, '_get_tar_file_hash', MagicMock(side_effect=['manifest_checksum']))
-    fakehashes = ['manifest_checksum', 'files_manifest_checksum', 'individual_file_checksum_modified']
-    monkeypatch.setattr(collection, '_consume_file', MagicMock(side_effect=fakehashes))
-    monkeypatch.setattr(collection, '_get_json_from_tar_file', MagicMock(side_effect=[manifest_info, files_manifest_info]))
-    monkeypatch.setattr(collection.os.path, 'isfile', MagicMock(return_value=True))
-
-    with patch.object(collection.display, 'display') as mock_display:
-        with patch.object(collection.display, 'vvv') as mock_debug:
-            local_collection.verify(remote_collection, './', './')
-
-            namespace = local_collection.namespace
-            name = local_collection.name
-
-            assert mock_display.call_count == 3
-            assert mock_display.call_args_list[0][0][0] == 'Collection %s.%s contains modified content in the following files:' % (namespace, name)
-            assert mock_display.call_args_list[1][0][0] == '%s.%s' % (namespace, name)
-            assert mock_display.call_args_list[2][0][0] == '    README.md'
-
-            # The -vvv output should show details (the checksums do not match)
-            assert mock_debug.call_count == 5
-            assert mock_debug.call_args_list[-1][0][0] == '    Expected: individual_file_checksum\n    Found: individual_file_checksum_modified'
-
-
-@patch.object(builtins, 'open', mock_open())
-def test_verify_identical(monkeypatch, mock_collection, manifest_info, files_manifest_info):
-
-    local_collection = mock_collection()
-    remote_collection = mock_collection(local=False)
-
-    monkeypatch.setattr(collection, '_get_tar_file_hash', MagicMock(side_effect=['manifest_checksum']))
-    monkeypatch.setattr(collection, '_consume_file', MagicMock(side_effect=['manifest_checksum', 'files_manifest_checksum', 'individual_file_checksum']))
-    monkeypatch.setattr(collection, '_get_json_from_tar_file', MagicMock(side_effect=[manifest_info, files_manifest_info]))
-    monkeypatch.setattr(collection.os.path, 'isfile', MagicMock(return_value=True))
-
-    with patch.object(collection.display, 'display') as mock_display:
-        with patch.object(collection.display, 'vvv') as mock_debug:
-            local_collection.verify(remote_collection, './', './')
-
-            # Successful verification is quiet
-            assert mock_display.call_count == 0
-
-            # The -vvv output should show the checksums not matching
-            namespace = local_collection.namespace
-            name = local_collection.name
-            version = local_collection.latest_version
-            success_msg = "Successfully verified that checksums for '%s.%s:%s' match the remote collection" % (namespace, name, version)
-
-            assert mock_debug.call_count == 4
-            assert mock_debug.call_args_list[-1][0][0] == success_msg
-
-
-@patch.object(os.path, 'isdir', return_value=True)
-def test_verify_collections_no_version(mock_isdir, mock_collection, monkeypatch):
-    namespace = 'ansible_namespace'
-    name = 'collection'
-    version = '*'  # Occurs if MANIFEST.json does not exist
-
-    local_collection = mock_collection(namespace=namespace, name=name, version=version)
-    monkeypatch.setattr(collection.CollectionRequirement, 'from_path', MagicMock(return_value=local_collection))
-
-    collections = [('%s.%s' % (namespace, name), version, None)]
-
-    with pytest.raises(AnsibleError) as err:
-        collection.verify_collections(collections, './', local_collection.api, False, False)
-
-    err_msg = 'Collection %s.%s does not appear to have a MANIFEST.json. ' % (namespace, name)
-    err_msg += 'A MANIFEST.json is expected if the collection has been built and installed via ansible-galaxy.'
-    assert err.value.message == err_msg
-
-
-@patch.object(collection.CollectionRequirement, 'verify')
-def test_verify_collections_not_installed(mock_verify, mock_collection, monkeypatch):
-    namespace = 'ansible_namespace'
-    name = 'collection'
-    version = '1.0.0'
-
-    local_collection = mock_collection(local_installed=False)
-
-    found_remote = MagicMock(return_value=mock_collection(local=False))
-    monkeypatch.setattr(collection.CollectionRequirement, 'from_name', found_remote)
-
-    collections = [('%s.%s' % (namespace, name), version, None, None)]
-    search_path = './'
-    validate_certs = False
-    ignore_errors = False
-    apis = [local_collection.api]
-
-    with patch.object(collection, '_download_file') as mock_download_file:
-        with pytest.raises(AnsibleError) as err:
-            collection.verify_collections(collections, search_path, apis, validate_certs, ignore_errors)
-
-    assert err.value.message == "Collection %s.%s is not installed in any of the collection paths." % (namespace, name)
-
-
-@patch.object(collection.CollectionRequirement, 'verify')
-def test_verify_collections_not_installed_ignore_errors(mock_verify, mock_collection, monkeypatch):
-    namespace = 'ansible_namespace'
-    name = 'collection'
-    version = '1.0.0'
-
-    local_collection = mock_collection(local_installed=False)
-
-    found_remote = MagicMock(return_value=mock_collection(local=False))
-    monkeypatch.setattr(collection.CollectionRequirement, 'from_name', found_remote)
-
-    collections = [('%s.%s' % (namespace, name), version, None)]
-    search_path = './'
-    validate_certs = False
-    ignore_errors = True
-    apis = [local_collection.api]
-
-    with patch.object(collection, '_download_file') as mock_download_file:
-        with patch.object(Display, 'warning') as mock_warning:
-            collection.verify_collections(collections, search_path, apis, validate_certs, ignore_errors)
-
-            skip_message = "Failed to verify collection %s.%s but skipping due to --ignore-errors being set." % (namespace, name)
-            original_err = "Error: Collection %s.%s is not installed in any of the collection paths." % (namespace, name)
-
-            assert mock_warning.called
-            assert mock_warning.call_args[0][0] == skip_message + " " + original_err
-
-
-@patch.object(os.path, 'isdir', return_value=True)
-@patch.object(collection.CollectionRequirement, 'verify')
-def test_verify_collections_no_remote(mock_verify, mock_isdir, mock_collection, monkeypatch):
-    namespace = 'ansible_namespace'
-    name = 'collection'
-    version = '1.0.0'
-
-    monkeypatch.setattr(os.path, 'isfile', MagicMock(side_effect=[False, True]))
-    monkeypatch.setattr(collection.CollectionRequirement, 'from_path', MagicMock(return_value=mock_collection()))
-
-    collections = [('%s.%s' % (namespace, name), version, None)]
-    search_path = './'
-    validate_certs = False
-    ignore_errors = False
-    apis = []
-
-    with pytest.raises(AnsibleError) as err:
-        collection.verify_collections(collections, search_path, apis, validate_certs, ignore_errors)
-
-    assert err.value.message == "Failed to find remote collection %s.%s:%s on any of the galaxy servers" % (namespace, name, version)
-
-
-@patch.object(os.path, 'isdir', return_value=True)
-@patch.object(collection.CollectionRequirement, 'verify')
-def test_verify_collections_no_remote_ignore_errors(mock_verify, mock_isdir, mock_collection, monkeypatch):
-    namespace = 'ansible_namespace'
-    name = 'collection'
-    version = '1.0.0'
-
-    monkeypatch.setattr(os.path, 'isfile', MagicMock(side_effect=[False, True]))
-    monkeypatch.setattr(collection.CollectionRequirement, 'from_path', MagicMock(return_value=mock_collection()))
-
-    collections = [('%s.%s' % (namespace, name), version, None)]
-    search_path = './'
-    validate_certs = False
-    ignore_errors = True
-    apis = []
-
-    with patch.object(Display, 'warning') as mock_warning:
-        collection.verify_collections(collections, search_path, apis, validate_certs, ignore_errors)
-
-        skip_message = "Failed to verify collection %s.%s but skipping due to --ignore-errors being set." % (namespace, name)
-        original_err = "Error: Failed to find remote collection %s.%s:%s on any of the galaxy servers" % (namespace, name, version)
-
-        assert mock_warning.called
-        assert mock_warning.call_args[0][0] == skip_message + " " + original_err
-
-
-def test_verify_collections_tarfile(monkeypatch):
-
-    monkeypatch.setattr(os.path, 'isfile', MagicMock(return_value=True))
-
-    invalid_format = 'ansible_namespace-collection-0.1.0.tar.gz'
-    collections = [(invalid_format, '*', None)]
-
-    with pytest.raises(AnsibleError) as err:
-        collection.verify_collections(collections, './', [], False, False)
-
-    msg = "'%s' is not a valid collection name. The format namespace.name is expected." % invalid_format
-    assert err.value.message == msg
-
-
-def test_verify_collections_path(monkeypatch):
-
-    monkeypatch.setattr(os.path, 'isfile', MagicMock(return_value=False))
-
-    invalid_format = 'collections/collection_namespace/collection_name'
-    collections = [(invalid_format, '*', None)]
-
-    with pytest.raises(AnsibleError) as err:
-        collection.verify_collections(collections, './', [], False, False)
-
-    msg = "'%s' is not a valid collection name. The format namespace.name is expected." % invalid_format
-    assert err.value.message == msg
-
-
-def test_verify_collections_url(monkeypatch):
-
-    monkeypatch.setattr(os.path, 'isfile', MagicMock(return_value=False))
-
-    invalid_format = 'https://galaxy.ansible.com/download/ansible_namespace-collection-0.1.0.tar.gz'
-    collections = [(invalid_format, '*', None)]
-
-    with pytest.raises(AnsibleError) as err:
-        collection.verify_collections(collections, './', [], False, False)
-
-    msg = "'%s' is not a valid collection name. The format namespace.name is expected." % invalid_format
-    assert err.value.message == msg
-
-
-@patch.object(os.path, 'isdir', return_value=True)
-@patch.object(collection.CollectionRequirement, 'verify')
-def test_verify_collections_name(mock_verify, mock_isdir, mock_collection, monkeypatch):
-    local_collection = mock_collection()
-    monkeypatch.setattr(collection.CollectionRequirement, 'from_path', MagicMock(return_value=local_collection))
-
-    monkeypatch.setattr(os.path, 'isfile', MagicMock(side_effect=[False, True, False]))
-
-    located_remote_from_name = MagicMock(return_value=mock_collection(local=False))
-    monkeypatch.setattr(collection.CollectionRequirement, 'from_name', located_remote_from_name)
-
-    with patch.object(collection, '_download_file') as mock_download_file:
-
-        collections = [('%s.%s' % (local_collection.namespace, local_collection.name), '%s' % local_collection.latest_version, None)]
-        search_path = './'
-        validate_certs = False
-        ignore_errors = False
-        apis = [local_collection.api]
-
-        collection.verify_collections(collections, search_path, apis, validate_certs, ignore_errors)
-
-        assert mock_download_file.call_count == 1
-        assert located_remote_from_name.call_count == 1

test/units/galaxy/test_collection_install.py

@@ -24,12 +24,24 @@ import ansible.module_utils.six.moves.urllib.error as urllib_error
 from ansible import context
 from ansible.cli.galaxy import GalaxyCLI
 from ansible.errors import AnsibleError
-from ansible.galaxy import collection, api
+from ansible.galaxy import collection, api, dependency_resolution
+from ansible.galaxy.dependency_resolution.dataclasses import Candidate, Requirement
 from ansible.module_utils._text import to_bytes, to_native, to_text
 from ansible.utils import context_objects as co
 from ansible.utils.display import Display
 
 
+class RequirementCandidates():
+    def __init__(self):
+        self.candidates = []
+
+    def func_wrapper(self, func):
+        def run(*args, **kwargs):
+            self.candidates = func(*args, **kwargs)
+            return self.candidates
+        return run
+
+
 def call_galaxy_cli(args):
     orig = co.GlobalCLIArgs._Singleton__instance
     co.GlobalCLIArgs._Singleton__instance = None
@@ -160,16 +172,14 @@ def galaxy_server():
 
 
 def test_build_requirement_from_path(collection_artifact):
-    actual = collection.CollectionRequirement.from_path(collection_artifact[0], True)
+    tmp_path = os.path.join(os.path.split(collection_artifact[1])[0], b'temp')
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(tmp_path, validate_certs=False)
+    actual = Requirement.from_dir_path_as_unknown(collection_artifact[0], concrete_artifact_cm)
 
     assert actual.namespace == u'ansible_namespace'
     assert actual.name == u'collection'
-    assert actual.b_path == collection_artifact[0]
+    assert actual.src == collection_artifact[0]
-    assert actual.api is None
+    assert actual.ver == u'0.1.0'
-    assert actual.skip is True
-    assert actual.versions == set([u'*'])
-    assert actual.latest_version == u'*'
-    assert actual.dependencies == {}
 
 
 @pytest.mark.parametrize('version', ['1.1.1', '1.1.0', '1.0.0'])
@@ -188,17 +198,15 @@ def test_build_requirement_from_path_with_manifest(version, collection_artifact)
     with open(manifest_path, 'wb') as manifest_obj:
         manifest_obj.write(to_bytes(manifest_value))
 
-    actual = collection.CollectionRequirement.from_path(collection_artifact[0], True)
+    tmp_path = os.path.join(os.path.split(collection_artifact[1])[0], b'temp')
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(tmp_path, validate_certs=False)
+    actual = Requirement.from_dir_path_as_unknown(collection_artifact[0], concrete_artifact_cm)
 
     # While the folder name suggests a different collection, we treat MANIFEST.json as the source of truth.
     assert actual.namespace == u'namespace'
     assert actual.name == u'name'
-    assert actual.b_path == collection_artifact[0]
+    assert actual.src == collection_artifact[0]
-    assert actual.api is None
+    assert actual.ver == to_text(version)
-    assert actual.skip is True
-    assert actual.versions == set([to_text(version)])
-    assert actual.latest_version == to_text(version)
-    assert actual.dependencies == {'ansible_namespace.collection': '*'}
 
 
 def test_build_requirement_from_path_invalid_manifest(collection_artifact):
@@ -206,12 +214,19 @@ def test_build_requirement_from_path_invalid_manifest(collection_artifact):
     with open(manifest_path, 'wb') as manifest_obj:
         manifest_obj.write(b"not json")
 
-    expected = "Collection file at '%s' does not contain a valid json string." % to_native(manifest_path)
+    tmp_path = os.path.join(os.path.split(collection_artifact[1])[0], b'temp')
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(tmp_path, validate_certs=False)
+
+    expected = "Collection tar file member MANIFEST.json does not contain a valid json string."
     with pytest.raises(AnsibleError, match=expected):
-        collection.CollectionRequirement.from_path(collection_artifact[0], True)
+        Requirement.from_dir_path_as_unknown(collection_artifact[0], concrete_artifact_cm)
 
 
-def test_build_requirement_from_path_no_version(collection_artifact, monkeypatch):
+def test_build_artifact_from_path_no_version(collection_artifact, monkeypatch):
+    mock_display = MagicMock()
+    monkeypatch.setattr(Display, 'display', mock_display)
+
+    # a collection artifact should always contain a valid version
     manifest_path = os.path.join(collection_artifact[0], b'MANIFEST.json')
     manifest_value = json.dumps({
         'collection_info': {
@@ -224,40 +239,56 @@ def test_build_requirement_from_path_no_version(collection_artifact, monkeypatch
     with open(manifest_path, 'wb') as manifest_obj:
         manifest_obj.write(to_bytes(manifest_value))
 
+    tmp_path = os.path.join(os.path.split(collection_artifact[1])[0], b'temp')
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(tmp_path, validate_certs=False)
+
+    expected = (
+        '^Collection metadata file at `.*` is expected to have a valid SemVer '
+        'version value but got {empty_unicode_string!r}$'.
+        format(empty_unicode_string=u'')
+    )
+    with pytest.raises(AnsibleError, match=expected):
+        Requirement.from_dir_path_as_unknown(collection_artifact[0], concrete_artifact_cm)
+
+
+def test_build_requirement_from_path_no_version(collection_artifact, monkeypatch):
     mock_display = MagicMock()
     monkeypatch.setattr(Display, 'display', mock_display)
 
-    actual = collection.CollectionRequirement.from_path(collection_artifact[0], True)
+    # version may be falsey/arbitrary strings for collections in development
+    manifest_path = os.path.join(collection_artifact[0], b'galaxy.yml')
+    metadata = {
+        'authors': ['Ansible'],
+        'readme': 'README.md',
+        'namespace': 'namespace',
+        'name': 'name',
+        'version': '',
+        'dependencies': {},
+    }
+    with open(manifest_path, 'wb') as manifest_obj:
+        manifest_obj.write(to_bytes(yaml.safe_dump(metadata)))
+
+    tmp_path = os.path.join(os.path.split(collection_artifact[1])[0], b'temp')
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(tmp_path, validate_certs=False)
+    actual = Requirement.from_dir_path_as_unknown(collection_artifact[0], concrete_artifact_cm)
 
     # While the folder name suggests a different collection, we treat MANIFEST.json as the source of truth.
     assert actual.namespace == u'namespace'
     assert actual.name == u'name'
-    assert actual.b_path == collection_artifact[0]
+    assert actual.src == collection_artifact[0]
-    assert actual.api is None
+    assert actual.ver == u'*'
-    assert actual.skip is True
-    assert actual.versions == set(['*'])
-    assert actual.latest_version == u'*'
-    assert actual.dependencies == {}
-
-    assert mock_display.call_count == 1
-
-    actual_warn = ' '.join(mock_display.mock_calls[0][1][0].split('\n'))
-    expected_warn = "Collection at '%s' does not have a valid version set, falling back to '*'. Found version: ''" \
-        % to_text(collection_artifact[0])
-    assert expected_warn in actual_warn
 
 
 def test_build_requirement_from_tar(collection_artifact):
-    actual = collection.CollectionRequirement.from_tar(collection_artifact[1], True, True)
+    tmp_path = os.path.join(os.path.split(collection_artifact[1])[0], b'temp')
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(tmp_path, validate_certs=False)
+
+    actual = Requirement.from_requirement_dict({'name': to_text(collection_artifact[1])}, concrete_artifact_cm)
 
     assert actual.namespace == u'ansible_namespace'
     assert actual.name == u'collection'
-    assert actual.b_path == collection_artifact[1]
+    assert actual.src == to_text(collection_artifact[1])
-    assert actual.api is None
+    assert actual.ver == u'0.1.0'
-    assert actual.skip is False
-    assert actual.versions == set([u'0.1.0'])
-    assert actual.latest_version == u'0.1.0'
-    assert actual.dependencies == {}
 
 
 def test_build_requirement_from_tar_fail_not_tar(tmp_path_factory):
@@ -266,9 +297,11 @@ def test_build_requirement_from_tar_fail_not_tar(tmp_path_factory):
     with open(test_file, 'wb') as test_obj:
         test_obj.write(b"\x00\x01\x02\x03")
 
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(test_dir, validate_certs=False)
+
     expected = "Collection artifact at '%s' is not a valid tar file." % to_native(test_file)
     with pytest.raises(AnsibleError, match=expected):
-        collection.CollectionRequirement.from_tar(test_file, True, True)
+        Requirement.from_requirement_dict({'name': to_text(test_file)}, concrete_artifact_cm)
 
 
 def test_build_requirement_from_tar_no_manifest(tmp_path_factory):
@@ -289,9 +322,11 @@ def test_build_requirement_from_tar_no_manifest(tmp_path_factory):
         tar_info.mode = 0o0644
         tfile.addfile(tarinfo=tar_info, fileobj=b_io)
 
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(test_dir, validate_certs=False)
+
     expected = "Collection at '%s' does not contain the required file MANIFEST.json." % to_native(tar_path)
     with pytest.raises(AnsibleError, match=expected):
-        collection.CollectionRequirement.from_tar(tar_path, True, True)
+        Requirement.from_requirement_dict({'name': to_text(tar_path)}, concrete_artifact_cm)
 
 
 def test_build_requirement_from_tar_no_files(tmp_path_factory):
@@ -311,9 +346,9 @@ def test_build_requirement_from_tar_no_files(tmp_path_factory):
         tar_info.mode = 0o0644
         tfile.addfile(tarinfo=tar_info, fileobj=b_io)
 
-    expected = "Collection at '%s' does not contain the required file FILES.json." % to_native(tar_path)
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(test_dir, validate_certs=False)
-    with pytest.raises(AnsibleError, match=expected):
+    with pytest.raises(KeyError, match='namespace'):
-        collection.CollectionRequirement.from_tar(tar_path, True, True)
+        Requirement.from_requirement_dict({'name': to_text(tar_path)}, concrete_artifact_cm)
 
 
 def test_build_requirement_from_tar_invalid_manifest(tmp_path_factory):
@@ -329,95 +364,128 @@ def test_build_requirement_from_tar_invalid_manifest(tmp_path_factory):
         tar_info.mode = 0o0644
         tfile.addfile(tarinfo=tar_info, fileobj=b_io)
 
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(test_dir, validate_certs=False)
+
     expected = "Collection tar file member MANIFEST.json does not contain a valid json string."
     with pytest.raises(AnsibleError, match=expected):
-        collection.CollectionRequirement.from_tar(tar_path, True, True)
+        Requirement.from_requirement_dict({'name': to_text(tar_path)}, concrete_artifact_cm)
 
 
-def test_build_requirement_from_name(galaxy_server, monkeypatch):
+def test_build_requirement_from_name(galaxy_server, monkeypatch, tmp_path_factory):
     mock_get_versions = MagicMock()
     mock_get_versions.return_value = ['2.1.9', '2.1.10']
     monkeypatch.setattr(galaxy_server, 'get_collection_versions', mock_get_versions)
 
-    actual = collection.CollectionRequirement.from_name('namespace.collection', [galaxy_server], '*', True, True)
+    mock_version_metadata = MagicMock(
+        namespace='namespace', name='collection',
+        version='2.1.10', artifact_sha256='', dependencies={}
+    )
+    monkeypatch.setattr(api.GalaxyAPI, 'get_collection_version_metadata', mock_version_metadata)
+
+    test_dir = to_bytes(tmp_path_factory.mktemp('test-ÅÑŚÌβŁÈ Collections Input'))
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(test_dir, validate_certs=False)
+
+    collections = ['namespace.collection']
+    requirements_file = None
+
+    cli = GalaxyCLI(args=['ansible-galaxy', 'collection', 'install', collections[0]])
+    requirements = cli._require_one_of_collections_requirements(
+        collections, requirements_file, artifacts_manager=concrete_artifact_cm
+    )['collections']
+    actual = collection._resolve_depenency_map(requirements, [galaxy_server], concrete_artifact_cm, None, True, False)['namespace.collection']
 
     assert actual.namespace == u'namespace'
     assert actual.name == u'collection'
-    assert actual.b_path is None
+    assert actual.ver == u'2.1.10'
-    assert actual.api == galaxy_server
+    assert actual.src == galaxy_server
-    assert actual.skip is False
-    assert actual.versions == set([u'2.1.9', u'2.1.10'])
-    assert actual.latest_version == u'2.1.10'
-    assert actual.dependencies == {}
 
     assert mock_get_versions.call_count == 1
     assert mock_get_versions.mock_calls[0][1] == ('namespace', 'collection')
 
 
-def test_build_requirement_from_name_with_prerelease(galaxy_server, monkeypatch):
+def test_build_requirement_from_name_with_prerelease(galaxy_server, monkeypatch, tmp_path_factory):
     mock_get_versions = MagicMock()
     mock_get_versions.return_value = ['1.0.1', '2.0.1-beta.1', '2.0.1']
     monkeypatch.setattr(galaxy_server, 'get_collection_versions', mock_get_versions)
 
-    actual = collection.CollectionRequirement.from_name('namespace.collection', [galaxy_server], '*', True, True)
+    mock_get_info = MagicMock()
+    mock_get_info.return_value = api.CollectionVersionMetadata('namespace', 'collection', '2.0.1', None, None, {})
+    monkeypatch.setattr(galaxy_server, 'get_collection_version_metadata', mock_get_info)
+
+    test_dir = to_bytes(tmp_path_factory.mktemp('test-ÅÑŚÌβŁÈ Collections Input'))
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(test_dir, validate_certs=False)
+
+    cli = GalaxyCLI(args=['ansible-galaxy', 'collection', 'install', 'namespace.collection'])
+    requirements = cli._require_one_of_collections_requirements(
+        ['namespace.collection'], None, artifacts_manager=concrete_artifact_cm
+    )['collections']
+    actual = collection._resolve_depenency_map(requirements, [galaxy_server], concrete_artifact_cm, None, True, False)['namespace.collection']
 
     assert actual.namespace == u'namespace'
     assert actual.name == u'collection'
-    assert actual.b_path is None
+    assert actual.src == galaxy_server
-    assert actual.api == galaxy_server
+    assert actual.ver == u'2.0.1'
-    assert actual.skip is False
-    assert actual.versions == set([u'1.0.1', u'2.0.1'])
-    assert actual.latest_version == u'2.0.1'
-    assert actual.dependencies == {}
 
     assert mock_get_versions.call_count == 1
     assert mock_get_versions.mock_calls[0][1] == ('namespace', 'collection')
 
 
-def test_build_requirment_from_name_with_prerelease_explicit(galaxy_server, monkeypatch):
+def test_build_requirment_from_name_with_prerelease_explicit(galaxy_server, monkeypatch, tmp_path_factory):
+    mock_get_versions = MagicMock()
+    mock_get_versions.return_value = ['1.0.1', '2.0.1-beta.1', '2.0.1']
+    monkeypatch.setattr(galaxy_server, 'get_collection_versions', mock_get_versions)
+
     mock_get_info = MagicMock()
     mock_get_info.return_value = api.CollectionVersionMetadata('namespace', 'collection', '2.0.1-beta.1', None, None,
                                                                {})
     monkeypatch.setattr(galaxy_server, 'get_collection_version_metadata', mock_get_info)
 
-    actual = collection.CollectionRequirement.from_name('namespace.collection', [galaxy_server], '2.0.1-beta.1', True,
+    test_dir = to_bytes(tmp_path_factory.mktemp('test-ÅÑŚÌβŁÈ Collections Input'))
-                                                        True)
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(test_dir, validate_certs=False)
+
+    cli = GalaxyCLI(args=['ansible-galaxy', 'collection', 'install', 'namespace.collection:2.0.1-beta.1'])
+    requirements = cli._require_one_of_collections_requirements(
+        ['namespace.collection:2.0.1-beta.1'], None, artifacts_manager=concrete_artifact_cm
+    )['collections']
+    actual = collection._resolve_depenency_map(requirements, [galaxy_server], concrete_artifact_cm, None, True, False)['namespace.collection']
 
     assert actual.namespace == u'namespace'
     assert actual.name == u'collection'
-    assert actual.b_path is None
+    assert actual.src == galaxy_server
-    assert actual.api == galaxy_server
+    assert actual.ver == u'2.0.1-beta.1'
-    assert actual.skip is False
-    assert actual.versions == set([u'2.0.1-beta.1'])
-    assert actual.latest_version == u'2.0.1-beta.1'
-    assert actual.dependencies == {}
 
     assert mock_get_info.call_count == 1
     assert mock_get_info.mock_calls[0][1] == ('namespace', 'collection', '2.0.1-beta.1')
 
 
-def test_build_requirement_from_name_second_server(galaxy_server, monkeypatch):
+def test_build_requirement_from_name_second_server(galaxy_server, monkeypatch, tmp_path_factory):
     mock_get_versions = MagicMock()
     mock_get_versions.return_value = ['1.0.1', '1.0.2', '1.0.3']
     monkeypatch.setattr(galaxy_server, 'get_collection_versions', mock_get_versions)
 
+    mock_get_info = MagicMock()
+    mock_get_info.return_value = api.CollectionVersionMetadata('namespace', 'collection', '1.0.3', None, None, {})
+    monkeypatch.setattr(galaxy_server, 'get_collection_version_metadata', mock_get_info)
+
     broken_server = copy.copy(galaxy_server)
     broken_server.api_server = 'https://broken.com/'
     mock_version_list = MagicMock()
     mock_version_list.return_value = []
     monkeypatch.setattr(broken_server, 'get_collection_versions', mock_version_list)
 
-    actual = collection.CollectionRequirement.from_name('namespace.collection', [broken_server, galaxy_server],
+    test_dir = to_bytes(tmp_path_factory.mktemp('test-ÅÑŚÌβŁÈ Collections Input'))
-                                                        '>1.0.1', False, True)
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(test_dir, validate_certs=False)
+
+    cli = GalaxyCLI(args=['ansible-galaxy', 'collection', 'install', 'namespace.collection:>1.0.1'])
+    requirements = cli._require_one_of_collections_requirements(
+        ['namespace.collection:>1.0.1'], None, artifacts_manager=concrete_artifact_cm
+    )['collections']
+    actual = collection._resolve_depenency_map(requirements, [broken_server, galaxy_server], concrete_artifact_cm, None, True, False)['namespace.collection']
 
     assert actual.namespace == u'namespace'
     assert actual.name == u'collection'
-    assert actual.b_path is None
+    assert actual.src == galaxy_server
-    # assert actual.api == galaxy_server
+    assert actual.ver == u'1.0.3'
-    assert actual.skip is False
-    assert actual.versions == set([u'1.0.2', u'1.0.3'])
-    assert actual.latest_version == u'1.0.3'
-    assert actual.dependencies == {}
 
     assert mock_version_list.call_count == 1
     assert mock_version_list.mock_calls[0][1] == ('namespace', 'collection')
@@ -426,53 +494,91 @@ def test_build_requirement_from_name_second_server(galaxy_server, monkeypatch):
     assert mock_get_versions.mock_calls[0][1] == ('namespace', 'collection')
 
 
-def test_build_requirement_from_name_missing(galaxy_server, monkeypatch):
+def test_build_requirement_from_name_missing(galaxy_server, monkeypatch, tmp_path_factory):
     mock_open = MagicMock()
     mock_open.return_value = []
 
     monkeypatch.setattr(galaxy_server, 'get_collection_versions', mock_open)
 
-    expected = "Failed to find collection namespace.collection:*"
+    test_dir = to_bytes(tmp_path_factory.mktemp('test-ÅÑŚÌβŁÈ Collections Input'))
-    with pytest.raises(AnsibleError, match=expected):
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(test_dir, validate_certs=False)
-        collection.CollectionRequirement.from_name('namespace.collection', [galaxy_server, galaxy_server], '*', False,
+
-                                                   True)
+    cli = GalaxyCLI(args=['ansible-galaxy', 'collection', 'install', 'namespace.collection:>1.0.1'])
+    requirements = cli._require_one_of_collections_requirements(
+        ['namespace.collection'], None, artifacts_manager=concrete_artifact_cm
+    )['collections']
+
+    expected = "Failed to resolve the requested dependencies map. Could not satisfy the following requirements:\n* namespace.collection:* (direct request)"
+    with pytest.raises(AnsibleError, match=re.escape(expected)):
+        collection._resolve_depenency_map(requirements, [galaxy_server, galaxy_server], concrete_artifact_cm, None, False, True)
 
 
-def test_build_requirement_from_name_401_unauthorized(galaxy_server, monkeypatch):
+def test_build_requirement_from_name_401_unauthorized(galaxy_server, monkeypatch, tmp_path_factory):
     mock_open = MagicMock()
     mock_open.side_effect = api.GalaxyError(urllib_error.HTTPError('https://galaxy.server.com', 401, 'msg', {},
                                                                    StringIO()), "error")
 
     monkeypatch.setattr(galaxy_server, 'get_collection_versions', mock_open)
 
+    test_dir = to_bytes(tmp_path_factory.mktemp('test-ÅÑŚÌβŁÈ Collections Input'))
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(test_dir, validate_certs=False)
+
+    cli = GalaxyCLI(args=['ansible-galaxy', 'collection', 'install', 'namespace.collection:>1.0.1'])
+    requirements = cli._require_one_of_collections_requirements(
+        ['namespace.collection'], None, artifacts_manager=concrete_artifact_cm
+    )['collections']
+
     expected = "error (HTTP Code: 401, Message: msg)"
     with pytest.raises(api.GalaxyError, match=re.escape(expected)):
-        collection.CollectionRequirement.from_name('namespace.collection', [galaxy_server, galaxy_server], '*', False)
+        collection._resolve_depenency_map(requirements, [galaxy_server, galaxy_server], concrete_artifact_cm, None, False, False)
 
 
-def test_build_requirement_from_name_single_version(galaxy_server, monkeypatch):
+def test_build_requirement_from_name_single_version(galaxy_server, monkeypatch, tmp_path_factory):
+    test_dir = to_bytes(tmp_path_factory.mktemp('test-ÅÑŚÌβŁÈ Collections Input'))
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(test_dir, validate_certs=False)
+    multi_api_proxy = collection.galaxy_api_proxy.MultiGalaxyAPIProxy([galaxy_server], concrete_artifact_cm)
+    dep_provider = dependency_resolution.providers.CollectionDependencyProvider(apis=multi_api_proxy, concrete_artifacts_manager=concrete_artifact_cm)
+
+    matches = RequirementCandidates()
+    mock_find_matches = MagicMock(side_effect=matches.func_wrapper(dep_provider.find_matches), autospec=True)
+    monkeypatch.setattr(dependency_resolution.providers.CollectionDependencyProvider, 'find_matches', mock_find_matches)
+
+    mock_get_versions = MagicMock()
+    mock_get_versions.return_value = ['2.0.0']
+    monkeypatch.setattr(galaxy_server, 'get_collection_versions', mock_get_versions)
+
     mock_get_info = MagicMock()
     mock_get_info.return_value = api.CollectionVersionMetadata('namespace', 'collection', '2.0.0', None, None,
                                                                {})
     monkeypatch.setattr(galaxy_server, 'get_collection_version_metadata', mock_get_info)
 
-    actual = collection.CollectionRequirement.from_name('namespace.collection', [galaxy_server], '2.0.0', True,
+    cli = GalaxyCLI(args=['ansible-galaxy', 'collection', 'install', 'namespace.collection:==2.0.0'])
-                                                        True)
+    requirements = cli._require_one_of_collections_requirements(
+        ['namespace.collection:==2.0.0'], None, artifacts_manager=concrete_artifact_cm
+    )['collections']
+
+    actual = collection._resolve_depenency_map(requirements, [galaxy_server], concrete_artifact_cm, None, False, True)['namespace.collection']
 
     assert actual.namespace == u'namespace'
     assert actual.name == u'collection'
-    assert actual.b_path is None
+    assert actual.src == galaxy_server
-    assert actual.api == galaxy_server
+    assert actual.ver == u'2.0.0'
-    assert actual.skip is False
+    assert [c.ver for c in matches.candidates] == [u'2.0.0']
-    assert actual.versions == set([u'2.0.0'])
-    assert actual.latest_version == u'2.0.0'
-    assert actual.dependencies == {}
 
     assert mock_get_info.call_count == 1
     assert mock_get_info.mock_calls[0][1] == ('namespace', 'collection', '2.0.0')
 
 
-def test_build_requirement_from_name_multiple_versions_one_match(galaxy_server, monkeypatch):
+def test_build_requirement_from_name_multiple_versions_one_match(galaxy_server, monkeypatch, tmp_path_factory):
+    test_dir = to_bytes(tmp_path_factory.mktemp('test-ÅÑŚÌβŁÈ Collections Input'))
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(test_dir, validate_certs=False)
+    multi_api_proxy = collection.galaxy_api_proxy.MultiGalaxyAPIProxy([galaxy_server], concrete_artifact_cm)
+    dep_provider = dependency_resolution.providers.CollectionDependencyProvider(apis=multi_api_proxy, concrete_artifacts_manager=concrete_artifact_cm)
+
+    matches = RequirementCandidates()
+    mock_find_matches = MagicMock(side_effect=matches.func_wrapper(dep_provider.find_matches), autospec=True)
+    monkeypatch.setattr(dependency_resolution.providers.CollectionDependencyProvider, 'find_matches', mock_find_matches)
+
     mock_get_versions = MagicMock()
     mock_get_versions.return_value = ['2.0.0', '2.0.1', '2.0.2']
     monkeypatch.setattr(galaxy_server, 'get_collection_versions', mock_get_versions)
@@ -482,17 +588,18 @@ def test_build_requirement_from_name_multiple_versions_one_match(galaxy_server,
                                                                {})
     monkeypatch.setattr(galaxy_server, 'get_collection_version_metadata', mock_get_info)
 
-    actual = collection.CollectionRequirement.from_name('namespace.collection', [galaxy_server], '>=2.0.1,<2.0.2',
+    cli = GalaxyCLI(args=['ansible-galaxy', 'collection', 'install', 'namespace.collection:>=2.0.1,<2.0.2'])
-                                                        True, True)
+    requirements = cli._require_one_of_collections_requirements(
+        ['namespace.collection:>=2.0.1,<2.0.2'], None, artifacts_manager=concrete_artifact_cm
+    )['collections']
+
+    actual = collection._resolve_depenency_map(requirements, [galaxy_server], concrete_artifact_cm, None, False, True)['namespace.collection']
 
     assert actual.namespace == u'namespace'
     assert actual.name == u'collection'
-    assert actual.b_path is None
+    assert actual.src == galaxy_server
-    assert actual.api == galaxy_server
+    assert actual.ver == u'2.0.1'
-    assert actual.skip is False
+    assert [c.ver for c in matches.candidates] == [u'2.0.1']
-    assert actual.versions == set([u'2.0.1'])
-    assert actual.latest_version == u'2.0.1'
-    assert actual.dependencies == {}
 
     assert mock_get_versions.call_count == 1
     assert mock_get_versions.mock_calls[0][1] == ('namespace', 'collection')
@@ -501,122 +608,118 @@ def test_build_requirement_from_name_multiple_versions_one_match(galaxy_server,
     assert mock_get_info.mock_calls[0][1] == ('namespace', 'collection', '2.0.1')
 
 
-def test_build_requirement_from_name_multiple_version_results(galaxy_server, monkeypatch):
+def test_build_requirement_from_name_multiple_version_results(galaxy_server, monkeypatch, tmp_path_factory):
+    test_dir = to_bytes(tmp_path_factory.mktemp('test-ÅÑŚÌβŁÈ Collections Input'))
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(test_dir, validate_certs=False)
+    multi_api_proxy = collection.galaxy_api_proxy.MultiGalaxyAPIProxy([galaxy_server], concrete_artifact_cm)
+    dep_provider = dependency_resolution.providers.CollectionDependencyProvider(apis=multi_api_proxy, concrete_artifacts_manager=concrete_artifact_cm)
+
+    matches = RequirementCandidates()
+    mock_find_matches = MagicMock(side_effect=matches.func_wrapper(dep_provider.find_matches), autospec=True)
+    monkeypatch.setattr(dependency_resolution.providers.CollectionDependencyProvider, 'find_matches', mock_find_matches)
+
+    mock_get_info = MagicMock()
+    mock_get_info.return_value = api.CollectionVersionMetadata('namespace', 'collection', '2.0.5', None, None, {})
+    monkeypatch.setattr(galaxy_server, 'get_collection_version_metadata', mock_get_info)
+
     mock_get_versions = MagicMock()
+    mock_get_versions.return_value = ['1.0.1', '1.0.2', '1.0.3']
+    monkeypatch.setattr(galaxy_server, 'get_collection_versions', mock_get_versions)
+
     mock_get_versions.return_value = ['2.0.0', '2.0.1', '2.0.2', '2.0.3', '2.0.4', '2.0.5']
     monkeypatch.setattr(galaxy_server, 'get_collection_versions', mock_get_versions)
 
-    actual = collection.CollectionRequirement.from_name('namespace.collection', [galaxy_server], '!=2.0.2',
+    cli = GalaxyCLI(args=['ansible-galaxy', 'collection', 'install', 'namespace.collection:!=2.0.2'])
-                                                        True, True)
+    requirements = cli._require_one_of_collections_requirements(
+        ['namespace.collection:!=2.0.2'], None, artifacts_manager=concrete_artifact_cm
+    )['collections']
+
+    actual = collection._resolve_depenency_map(requirements, [galaxy_server], concrete_artifact_cm, None, False, True)['namespace.collection']
 
     assert actual.namespace == u'namespace'
     assert actual.name == u'collection'
-    assert actual.b_path is None
+    assert actual.src == galaxy_server
-    assert actual.api == galaxy_server
+    assert actual.ver == u'2.0.5'
-    assert actual.skip is False
+    # should be ordered latest to earliest
-    assert actual.versions == set([u'2.0.0', u'2.0.1', u'2.0.3', u'2.0.4', u'2.0.5'])
+    assert [c.ver for c in matches.candidates] == [u'2.0.5', u'2.0.4', u'2.0.3', u'2.0.1', u'2.0.0']
-    assert actual.latest_version == u'2.0.5'
-    assert actual.dependencies == {}
 
     assert mock_get_versions.call_count == 1
     assert mock_get_versions.mock_calls[0][1] == ('namespace', 'collection')
 
 
-@pytest.mark.parametrize('versions, requirement, expected_filter, expected_latest', [
+def test_candidate_with_conflict(monkeypatch, tmp_path_factory, galaxy_server):
-    [['1.0.0', '1.0.1'], '*', ['1.0.0', '1.0.1'], '1.0.1'],
+
-    [['1.0.0', '1.0.5', '1.1.0'], '>1.0.0,<1.1.0', ['1.0.5'], '1.0.5'],
+    test_dir = to_bytes(tmp_path_factory.mktemp('test-ÅÑŚÌβŁÈ Collections Input'))
-    [['1.0.0', '1.0.5', '1.1.0'], '>1.0.0,<=1.0.5', ['1.0.5'], '1.0.5'],
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(test_dir, validate_certs=False)
-    [['1.0.0', '1.0.5', '1.1.0'], '>=1.1.0', ['1.1.0'], '1.1.0'],
+
-    [['1.0.0', '1.0.5', '1.1.0'], '!=1.1.0', ['1.0.0', '1.0.5'], '1.0.5'],
+    mock_get_info = MagicMock()
-    [['1.0.0', '1.0.5', '1.1.0'], '==1.0.5', ['1.0.5'], '1.0.5'],
+    mock_get_info.return_value = api.CollectionVersionMetadata('namespace', 'collection', '2.0.5', None, None, {})
-    [['1.0.0', '1.0.5', '1.1.0'], '1.0.5', ['1.0.5'], '1.0.5'],
+    monkeypatch.setattr(galaxy_server, 'get_collection_version_metadata', mock_get_info)
-    [['1.0.0', '2.0.0', '3.0.0'], '>=2', ['2.0.0', '3.0.0'], '3.0.0'],
+
-])
+    mock_get_versions = MagicMock()
-def test_add_collection_requirements(versions, requirement, expected_filter, expected_latest):
+    mock_get_versions.return_value = ['2.0.5']
-    req = collection.CollectionRequirement('namespace', 'name', None, 'https://galaxy.com', versions, requirement,
+    monkeypatch.setattr(galaxy_server, 'get_collection_versions', mock_get_versions)
-                                           False)
+
-    assert req.versions == set(expected_filter)
+    cli = GalaxyCLI(args=['ansible-galaxy', 'collection', 'install', 'namespace.collection:!=2.0.5'])
-    assert req.latest_version == expected_latest
+    requirements = cli._require_one_of_collections_requirements(
+        ['namespace.collection:!=2.0.5'], None, artifacts_manager=concrete_artifact_cm
+    )['collections']
+
+    expected = "Failed to resolve the requested dependencies map. Could not satisfy the following requirements:\n"
+    expected += "* namespace.collection:!=2.0.5 (direct request)"
+    with pytest.raises(AnsibleError, match=re.escape(expected)):
+        collection._resolve_depenency_map(requirements, [galaxy_server], concrete_artifact_cm, None, False, True)
 
 
-def test_add_collection_requirement_to_unknown_installed_version(monkeypatch):
+def test_dep_candidate_with_conflict(monkeypatch, tmp_path_factory, galaxy_server):
+    test_dir = to_bytes(tmp_path_factory.mktemp('test-ÅÑŚÌβŁÈ Collections Input'))
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(test_dir, validate_certs=False)
+
+    mock_get_info_return = [
+        api.CollectionVersionMetadata('parent', 'collection', '2.0.5', None, None, {'namespace.collection': '!=1.0.0'}),
+        api.CollectionVersionMetadata('namespace', 'collection', '1.0.0', None, None, {}),
+    ]
+    mock_get_info = MagicMock(side_effect=mock_get_info_return)
+    monkeypatch.setattr(galaxy_server, 'get_collection_version_metadata', mock_get_info)
+
+    mock_get_versions = MagicMock(side_effect=[['2.0.5'], ['1.0.0']])
+    monkeypatch.setattr(galaxy_server, 'get_collection_versions', mock_get_versions)
+
+    cli = GalaxyCLI(args=['ansible-galaxy', 'collection', 'install', 'parent.collection:2.0.5'])
+    requirements = cli._require_one_of_collections_requirements(
+        ['parent.collection:2.0.5'], None, artifacts_manager=concrete_artifact_cm
+    )['collections']
+
+    expected = "Failed to resolve the requested dependencies map. Could not satisfy the following requirements:\n"
+    expected += "* namespace.collection:!=1.0.0 (dependency of parent.collection:2.0.5)"
+    with pytest.raises(AnsibleError, match=re.escape(expected)):
+        collection._resolve_depenency_map(requirements, [galaxy_server], concrete_artifact_cm, None, False, True)
+
+
+def test_install_installed_collection(monkeypatch, tmp_path_factory, galaxy_server):
+
+    mock_installed_collections = MagicMock(return_value=[Candidate('namespace.collection', '1.2.3', None, 'dir')])
+
+    monkeypatch.setattr(collection, 'find_existing_collections', mock_installed_collections)
+
+    test_dir = to_text(tmp_path_factory.mktemp('test-ÅÑŚÌβŁÈ Collections'))
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(test_dir, validate_certs=False)
+
     mock_display = MagicMock()
     monkeypatch.setattr(Display, 'display', mock_display)
 
-    req = collection.CollectionRequirement('namespace', 'name', None, 'https://galaxy.com', ['*'], '*', False,
+    mock_get_info = MagicMock()
-                                           skip=True)
+    mock_get_info.return_value = api.CollectionVersionMetadata('namespace', 'collection', '1.2.3', None, None, {})
+    monkeypatch.setattr(galaxy_server, 'get_collection_version_metadata', mock_get_info)
 
-    req.add_requirement('parent.collection', '1.0.0')
+    mock_get_versions = MagicMock(return_value=['1.2.3', '1.3.0'])
-    assert req.latest_version == '*'
+    monkeypatch.setattr(galaxy_server, 'get_collection_versions', mock_get_versions)
 
-    assert mock_display.call_count == 1
+    cli = GalaxyCLI(args=['ansible-galaxy', 'collection', 'install', 'namespace.collection'])
+    cli.run()
 
-    actual_warn = ' '.join(mock_display.mock_calls[0][1][0].split('\n'))
+    expected = "Nothing to do. All requested collections are already installed. If you want to reinstall them, consider using `--force`."
-    assert "Failed to validate the collection requirement 'namespace.name:1.0.0' for parent.collection" in actual_warn
+    assert mock_display.mock_calls[1][1][0] == expected
-
-
-def test_add_collection_wildcard_requirement_to_unknown_installed_version():
-    req = collection.CollectionRequirement('namespace', 'name', None, 'https://galaxy.com', ['*'], '*', False,
-                                           skip=True)
-    req.add_requirement(str(req), '*')
-
-    assert req.versions == set('*')
-    assert req.latest_version == '*'
-
-
-def test_add_collection_requirement_with_conflict(galaxy_server):
-    expected = "Cannot meet requirement ==1.0.2 for dependency namespace.name from source '%s'. Available versions " \
-               "before last requirement added: 1.0.0, 1.0.1\n" \
-               "Requirements from:\n" \
-               "\tbase - 'namespace.name:==1.0.2'" % galaxy_server.api_server
-    with pytest.raises(AnsibleError, match=expected):
-        collection.CollectionRequirement('namespace', 'name', None, galaxy_server, ['1.0.0', '1.0.1'], '==1.0.2',
-                                         False)
-
-
-def test_add_requirement_to_existing_collection_with_conflict(galaxy_server):
-    req = collection.CollectionRequirement('namespace', 'name', None, galaxy_server, ['1.0.0', '1.0.1'], '*', False)
-
-    expected = "Cannot meet dependency requirement 'namespace.name:1.0.2' for collection namespace.collection2 from " \
-               "source '%s'. Available versions before last requirement added: 1.0.0, 1.0.1\n" \
-               "Requirements from:\n" \
-               "\tbase - 'namespace.name:*'\n" \
-               "\tnamespace.collection2 - 'namespace.name:1.0.2'" % galaxy_server.api_server
-    with pytest.raises(AnsibleError, match=re.escape(expected)):
-        req.add_requirement('namespace.collection2', '1.0.2')
-
-
-def test_add_requirement_to_installed_collection_with_conflict():
-    source = 'https://galaxy.ansible.com'
-    req = collection.CollectionRequirement('namespace', 'name', None, source, ['1.0.0', '1.0.1'], '*', False,
-                                           skip=True)
-
-    expected = "Cannot meet requirement namespace.name:1.0.2 as it is already installed at version '1.0.1'. " \
-               "Use --force to overwrite"
-    with pytest.raises(AnsibleError, match=re.escape(expected)):
-        req.add_requirement(None, '1.0.2')
-
-
-def test_add_requirement_to_installed_collection_with_conflict_as_dep():
-    source = 'https://galaxy.ansible.com'
-    req = collection.CollectionRequirement('namespace', 'name', None, source, ['1.0.0', '1.0.1'], '*', False,
-                                           skip=True)
-
-    expected = "Cannot meet requirement namespace.name:1.0.2 as it is already installed at version '1.0.1'. " \
-               "Use --force-with-deps to overwrite"
-    with pytest.raises(AnsibleError, match=re.escape(expected)):
-        req.add_requirement('namespace.collection2', '1.0.2')
-
-
-def test_install_skipped_collection(monkeypatch):
-    mock_display = MagicMock()
-    monkeypatch.setattr(Display, 'display', mock_display)
-
-    req = collection.CollectionRequirement('namespace', 'name', None, 'source', ['1.0.0'], '*', False, skip=True)
-    req.install(None, None)
-
-    assert mock_display.call_count == 1
-    assert mock_display.mock_calls[0][1][0] == "Skipping 'namespace.name' as it is already installed"
 
 
 def test_install_collection(collection_artifact, monkeypatch):
@@ -624,15 +727,17 @@ def test_install_collection(collection_artifact, monkeypatch):
     monkeypatch.setattr(Display, 'display', mock_display)
 
     collection_tar = collection_artifact[1]
-    output_path = os.path.join(os.path.split(collection_tar)[0], b'output')
-    collection_path = os.path.join(output_path, b'ansible_namespace', b'collection')
-    os.makedirs(os.path.join(collection_path, b'delete_me'))  # Create a folder to verify the install cleans out the dir
 
     temp_path = os.path.join(os.path.split(collection_tar)[0], b'temp')
     os.makedirs(temp_path)
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(temp_path, validate_certs=False)
 
-    req = collection.CollectionRequirement.from_tar(collection_tar, True, True)
+    output_path = os.path.join(os.path.split(collection_tar)[0])
-    req.install(to_text(output_path), temp_path)
+    collection_path = os.path.join(output_path, b'ansible_namespace', b'collection')
+    os.makedirs(os.path.join(collection_path, b'delete_me'))  # Create a folder to verify the install cleans out the dir
+
+    candidate = Candidate('ansible_namespace.collection', '0.1.0', to_text(collection_tar), 'file')
+    collection.install(candidate, to_text(output_path), concrete_artifact_cm)
 
     # Ensure the temp directory is empty, nothing is left behind
     assert os.listdir(temp_path) == []
@@ -649,33 +754,29 @@ def test_install_collection(collection_artifact, monkeypatch):
     assert mock_display.call_count == 2
     assert mock_display.mock_calls[0][1][0] == "Installing 'ansible_namespace.collection:0.1.0' to '%s'" \
         % to_text(collection_path)
-    assert mock_display.mock_calls[1][1][0] == "ansible_namespace.collection (0.1.0) was installed successfully"
+    assert mock_display.mock_calls[1][1][0] == "ansible_namespace.collection:0.1.0 was installed successfully"
 
 
 def test_install_collection_with_download(galaxy_server, collection_artifact, monkeypatch):
-    collection_tar = collection_artifact[1]
+    collection_path, collection_tar = collection_artifact
-    output_path = os.path.join(os.path.split(collection_tar)[0], b'output')
+    shutil.rmtree(collection_path)
-    collection_path = os.path.join(output_path, b'ansible_namespace', b'collection')
+
+    collections_dir = ('%s' % os.path.sep).join(to_text(collection_path).split('%s' % os.path.sep)[:-2])
+
+    temp_path = os.path.join(os.path.split(collection_tar)[0], b'temp')
+    os.makedirs(temp_path)
 
     mock_display = MagicMock()
     monkeypatch.setattr(Display, 'display', mock_display)
 
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(temp_path, validate_certs=False)
+
     mock_download = MagicMock()
     mock_download.return_value = collection_tar
-    monkeypatch.setattr(collection, '_download_file', mock_download)
+    monkeypatch.setattr(concrete_artifact_cm, 'get_galaxy_artifact_path', mock_download)
 
-    monkeypatch.setattr(galaxy_server, '_available_api_versions', {'v2': 'v2/'})
+    req = Requirement('ansible_namespace.collection', '0.1.0', 'https://downloadme.com', 'galaxy')
-    temp_path = os.path.join(os.path.split(collection_tar)[0], b'temp')
+    collection.install(req, to_text(collections_dir), concrete_artifact_cm)
-    os.makedirs(temp_path)
-
-    meta = api.CollectionVersionMetadata('ansible_namespace', 'collection', '0.1.0', 'https://downloadme.com',
-                                         'myhash', {})
-    req = collection.CollectionRequirement('ansible_namespace', 'collection', None, galaxy_server,
-                                           ['0.1.0'], '*', False, metadata=meta)
-    req.install(to_text(output_path), temp_path)
-
-    # Ensure the temp directory is empty, nothing is left behind
-    assert os.listdir(temp_path) == []
 
     actual_files = os.listdir(collection_path)
     actual_files.sort()
@@ -685,13 +786,11 @@ def test_install_collection_with_download(galaxy_server, collection_artifact, mo
     assert mock_display.call_count == 2
     assert mock_display.mock_calls[0][1][0] == "Installing 'ansible_namespace.collection:0.1.0' to '%s'" \
         % to_text(collection_path)
-    assert mock_display.mock_calls[1][1][0] == "ansible_namespace.collection (0.1.0) was installed successfully"
+    assert mock_display.mock_calls[1][1][0] == "ansible_namespace.collection:0.1.0 was installed successfully"
 
     assert mock_download.call_count == 1
-    assert mock_download.mock_calls[0][1][0] == 'https://downloadme.com'
+    assert mock_download.mock_calls[0][1][0].src == 'https://downloadme.com'
-    assert mock_download.mock_calls[0][1][1] == temp_path
+    assert mock_download.mock_calls[0][1][0].type == 'galaxy'
-    assert mock_download.mock_calls[0][1][2] == 'myhash'
-    assert mock_download.mock_calls[0][1][3] is True
 
 
 def test_install_collections_from_tar(collection_artifact, monkeypatch):
@@ -702,8 +801,10 @@ def test_install_collections_from_tar(collection_artifact, monkeypatch):
     mock_display = MagicMock()
     monkeypatch.setattr(Display, 'display', mock_display)
 
-    collection.install_collections([(to_text(collection_tar), '*', None, None)], to_text(temp_path),
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(temp_path, validate_certs=False)
-                                   [u'https://galaxy.ansible.com'], True, False, False, False, False)
+
+    requirements = [Requirement('ansible_namespace.collection', '0.1.0', to_text(collection_tar), 'file')]
+    collection.install_collections(requirements, to_text(temp_path), [], False, False, False, False, False, concrete_artifact_cm)
 
     assert os.path.isdir(collection_path)
 
@@ -734,9 +835,12 @@ def test_install_collections_existing_without_force(collection_artifact, monkeyp
     mock_display = MagicMock()
     monkeypatch.setattr(Display, 'display', mock_display)
 
-    # If we don't delete collection_path it will think the original build skeleton is installed so we expect a skip
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(temp_path, validate_certs=False)
-    collection.install_collections([(to_text(collection_tar), '*', None, None)], to_text(temp_path),
+
-                                   [u'https://galaxy.ansible.com'], True, False, False, False, False)
+    assert os.path.isdir(collection_path)
+
+    requirements = [Requirement('ansible_namespace.collection', '0.1.0', to_text(collection_tar), 'file')]
+    collection.install_collections(requirements, to_text(temp_path), [], False, False, False, False, False, concrete_artifact_cm)
 
     assert os.path.isdir(collection_path)
 
@@ -746,11 +850,9 @@ def test_install_collections_existing_without_force(collection_artifact, monkeyp
 
     # Filter out the progress cursor display calls.
     display_msgs = [m[1][0] for m in mock_display.mock_calls if 'newline' not in m[2] and len(m[1]) == 1]
-    assert len(display_msgs) == 3
+    assert len(display_msgs) == 1
 
-    assert display_msgs[0] == "Process install dependency map"
+    assert display_msgs[0] == 'Nothing to do. All requested collections are already installed. If you want to reinstall them, consider using `--force`.'
-    assert display_msgs[1] == "Starting collection install process"
-    assert display_msgs[2] == "Skipping 'ansible_namespace.collection' as it is already installed"
 
     for msg in display_msgs:
         assert 'WARNING' not in msg
@@ -768,8 +870,9 @@ def test_install_missing_metadata_warning(collection_artifact, monkeypatch):
         if os.path.isfile(b_path):
             os.unlink(b_path)
 
-    collection.install_collections([(to_text(collection_tar), '*', None, None)], to_text(temp_path),
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(temp_path, validate_certs=False)
-                                   [u'https://galaxy.ansible.com'], True, False, False, False, False)
+    requirements = [Requirement('ansible_namespace.collection', '0.1.0', to_text(collection_tar), 'file')]
+    collection.install_collections(requirements, to_text(temp_path), [], False, False, False, False, False, concrete_artifact_cm)
 
     display_msgs = [m[1][0] for m in mock_display.mock_calls if 'newline' not in m[2] and len(m[1]) == 1]
 
@@ -788,8 +891,9 @@ def test_install_collection_with_circular_dependency(collection_artifact, monkey
     mock_display = MagicMock()
     monkeypatch.setattr(Display, 'display', mock_display)
 
-    collection.install_collections([(to_text(collection_tar), '*', None, None)], to_text(temp_path),
+    concrete_artifact_cm = collection.concrete_artifact_manager.ConcreteArtifactsManager(temp_path, validate_certs=False)
-                                   [u'https://galaxy.ansible.com'], True, False, False, False, False)
+    requirements = [Requirement('ansible_namespace.collection', '0.1.0', to_text(collection_tar), 'file')]
+    collection.install_collections(requirements, to_text(temp_path), [], False, False, False, False, False, concrete_artifact_cm)
 
     assert os.path.isdir(collection_path)
 
@@ -811,4 +915,4 @@ def test_install_collection_with_circular_dependency(collection_artifact, monkey
     assert display_msgs[0] == "Process install dependency map"
     assert display_msgs[1] == "Starting collection install process"
     assert display_msgs[2] == "Installing 'ansible_namespace.collection:0.1.0' to '%s'" % to_text(collection_path)
-    assert display_msgs[3] == "ansible_namespace.collection (0.1.0) was installed successfully"
+    assert display_msgs[3] == "ansible_namespace.collection:0.1.0 was installed successfully"