ansible/lib/ansible/plugins/lookup/__init__.py
Matt Martz 9773a1f289
Add a Singleton metaclass, use it with Display (#48935)
* Add a Singleton class, use it with Display

* update six import

* Move remaining failes to display singleton

* Fix rebase issues

* Singleton improvements

* Add code-smell for 'from __main__ import display'. ci_complete

* s/self/cls/g

* Add docs for no-main-display

* Address linting issues

* Add changelog fragment. ci_complete

* Implement reentrant lock for class instantiation in Singleton

* Add Display singleton porting guide
2018-11-20 17:06:51 -06:00

125 lines
4.3 KiB
Python

# (c) 2012-2014, Michael DeHaan <michael.dehaan@gmail.com>
#
# This file is part of Ansible
#
# Ansible is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Ansible. If not, see <http://www.gnu.org/licenses/>.
# Make coding more python3-ish
from __future__ import (absolute_import, division, print_function)
__metaclass__ = type
from abc import abstractmethod
from ansible.errors import AnsibleFileNotFound
from ansible.plugins import AnsiblePlugin
from ansible.utils.display import Display
display = Display()
__all__ = ['LookupBase']
class LookupBase(AnsiblePlugin):
def __init__(self, loader=None, templar=None, **kwargs):
super(LookupBase, self).__init__()
self._loader = loader
self._templar = templar
# Backwards compat: self._display isn't really needed, just import the global display and use that.
self._display = display
def get_basedir(self, variables):
if 'role_path' in variables:
return variables['role_path']
else:
return self._loader.get_basedir()
@staticmethod
def _flatten(terms):
ret = []
for term in terms:
if isinstance(term, (list, tuple)):
ret.extend(term)
else:
ret.append(term)
return ret
@staticmethod
def _combine(a, b):
results = []
for x in a:
for y in b:
results.append(LookupBase._flatten([x, y]))
return results
@staticmethod
def _flatten_hash_to_list(terms):
ret = []
for key in terms:
ret.append({'key': key, 'value': terms[key]})
return ret
@abstractmethod
def run(self, terms, variables=None, **kwargs):
"""
When the playbook specifies a lookup, this method is run. The
arguments to the lookup become the arguments to this method. One
additional keyword argument named ``variables`` is added to the method
call. It contains the variables available to ansible at the time the
lookup is templated. For instance::
"{{ lookup('url', 'https://toshio.fedorapeople.org/one.txt', validate_certs=True) }}"
would end up calling the lookup plugin named url's run method like this::
run(['https://toshio.fedorapeople.org/one.txt'], variables=available_variables, validate_certs=True)
Lookup plugins can be used within playbooks for looping. When this
happens, the first argument is a list containing the terms. Lookup
plugins can also be called from within playbooks to return their
values into a variable or parameter. If the user passes a string in
this case, it is converted into a list.
Errors encountered during execution should be returned by raising
AnsibleError() with a message describing the error.
Any strings returned by this method that could ever contain non-ascii
must be converted into python's unicode type as the strings will be run
through jinja2 which has this requirement. You can use::
from ansible.module_utils._text import to_text
result_string = to_text(result_string)
"""
pass
def find_file_in_search_path(self, myvars, subdir, needle, ignore_missing=False):
'''
Return a file (needle) in the task's expected search path.
'''
if 'ansible_search_path' in myvars:
paths = myvars['ansible_search_path']
else:
paths = [self.get_basedir(myvars)]
result = None
try:
result = self._loader.path_dwim_relative_stack(paths, subdir, needle)
except AnsibleFileNotFound:
if not ignore_missing:
self._display.warning("Unable to find '%s' in expected paths (use -vvvvv to see paths)" % needle)
return result