alternatives: handle absent link, add integration tests (#27967)

* alternatives: add integration tests

* alternatives: handle absent link (fix AttributeError)

Error occurred at least on Debian Stretch and OpenSuse 42.2:
Traceback (most recent call last):
  File "/tmp/ansible_RY6X41/ansible_module_alternatives.py", line 161, in <module>
    main()
  File "/tmp/ansible_RY6X41/ansible_module_alternatives.py", line 113, in main
    current_path = current_path_regex.search(display_output).group(1)
AttributeError: 'NoneType' object has no attribute 'group'

update-alternatives stdout sample:
dummy - manual mode
  link best version is /usr/bin/dummy1
  link currently absent
  link dummy is /usr/bin/dummy

* alternatives: PEP 8 fixes

* alternatives: fix copyright in integration tests

* alternatives: nested loops handle more than 2 items

Thanks to Michael Scherer (@mscherer) for pointing that.

* alternatives: enable integration tests

lib/ansible/modules/system/alternatives.py

@@ -77,11 +77,11 @@ from ansible.module_utils.basic import AnsibleModule
 def main():
 
     module = AnsibleModule(
-        argument_spec = dict(
-            name = dict(required=True),
-            path = dict(required=True, type='path'),
-            link = dict(required=False, type='path'),
-            priority = dict(required=False, type='int',
+        argument_spec=dict(
+            name=dict(required=True),
+            path=dict(required=True, type='path'),
+            link=dict(required=False, type='path'),
+            priority=dict(required=False, type='int',
                           default=50),
         ),
         supports_check_mode=True,
@@ -93,7 +93,7 @@ def main():
     link = params['link']
     priority = params['priority']
 
-    UPDATE_ALTERNATIVES = module.get_bin_path('update-alternatives',True)
+    UPDATE_ALTERNATIVES = module.get_bin_path('update-alternatives', True)
 
     current_path = None
     all_alternatives = []
@@ -111,7 +111,9 @@ def main():
                                         re.MULTILINE)
         alternative_regex = re.compile(r'^(\/.*)\s-\spriority', re.MULTILINE)
 
-        current_path = current_path_regex.search(display_output).group(1)
+        match = current_path_regex.search(display_output)
+        if match:
+            current_path = match.group(1)
         all_alternatives = alternative_regex.findall(display_output)
 
         if not link:

test/integration/targets/alternatives/aliases

@@ -0,0 +1,5 @@
+posix/ci/group3
+destructive
+needs/root
+skip/freebsd
+skip/osx

test/integration/targets/alternatives/tasks/main.yml

@@ -0,0 +1,62 @@
+# Copyright (c) 2017 Pierre-Louis Bonicoli <pierre-louis.bonicoli@libregerbil.fr>
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+- name: 'setup: create a dummy alternative'
+  block:
+  - import_tasks: setup.yml
+
+  ##############
+  # Test parameters:
+  # link parameter present / absent ('with_link' variable)
+  # with / without alternatives defined in alternatives file ('with_alternatives' variable)
+  # auto / manual ('mode' variable)
+
+  - include_tasks: tests.yml
+    with_nested:
+        - [ True, False ] # with_link
+        - [ True, False ] # with_alternatives
+        - [ 'auto', 'manual' ] # mode
+    loop_control:
+      loop_var: test_conf
+
+  ##########
+  # Priority
+  - block:
+    - include_tasks: remove_links.yml
+    - include_tasks: setup_test.yml
+    # at least two iterations again
+    - include_tasks: tests_set_priority.yml
+      with_sequence: start=3 end=4
+    vars:
+      with_alternatives: True
+      mode: auto
+
+  - block:
+    - include_tasks: remove_links.yml
+    - include_tasks: setup_test.yml
+    # at least two iterations again
+    - include_tasks: tests_set_priority.yml
+      with_sequence: start=3 end=4
+    vars:
+      with_alternatives: False
+      mode: auto
+  always:
+    - include_tasks: remove_links.yml
+
+    - file:
+        path: '{{ item }}'
+        state: absent
+      with_items:
+        - '{{ alternatives_dir }}/dummy'
+
+    - file:
+        path: '/usr/bin/dummy{{ item }}'
+        state: absent
+      with_sequence: start=1 end=4
+  # *Disable tests on Fedora 24*
+  # Shippable Fedora 24 image provides chkconfig-1.7-2.fc24.x86_64 but not the
+  # latest available version (chkconfig-1.8-1.fc24.x86_64). update-alternatives
+  # in chkconfig-1.7-2 fails when /etc/alternatives/dummy link is missing,
+  # error is: 'failed to read link /usr/bin/dummy: No such file or directory'.
+  # Moreover Fedora 24 is no longer maintained.
+  when: ansible_distribution != 'Fedora' or ansible_distribution_major_version|int > 24

test/integration/targets/alternatives/tasks/remove_links.yml

@@ -0,0 +1,7 @@
+- name: remove links
+  file:
+    path: '{{ item }}'
+    state: absent
+  with_items:
+    - /etc/alternatives/dummy
+    - /usr/bin/dummy

test/integration/targets/alternatives/tasks/setup.yml

@@ -0,0 +1,14 @@
+- include_vars: '{{ item }}'
+  with_first_found:
+    - files:
+        - '{{ ansible_os_family }}.yml'
+        - 'default.yml'
+      paths: '../vars'
+
+- template:
+    src: dummy_command
+    dest: '/usr/bin/dummy{{ item }}'
+    owner: root
+    group: root
+    mode: 0755
+  with_sequence: start=1 end=4

test/integration/targets/alternatives/tasks/setup_test.yml

@@ -0,0 +1,22 @@
+- template:
+    src: dummy_alternative
+    dest: '{{ alternatives_dir }}/dummy'
+    owner: root
+    group: root
+    mode: 0644
+  when: with_alternatives or ansible_os_family != 'RedHat'
+
+# update-alternatives included in Fedora 26 (1.10) & Red Hat 7.4 (1.8) segfaults
+# when <admindir>/dummy file contains only mode and link. Hence the file is
+# deleted instead of containing only mode and link. The file below works fine with
+# newer version of update-alternatives:
+# """
+# auto
+# /usr/bin/dummy
+#
+#
+# """
+- file:
+    path: '{{ alternatives_dir }}/dummy'
+    state: absent
+  when: not with_alternatives and ansible_os_family == 'RedHat'

test/integration/targets/alternatives/tasks/test.yml

@@ -0,0 +1,53 @@
+- debug:
+    msg: ' with_alternatives: {{ with_alternatives }}, mode: {{ mode }}'
+
+- block:
+  - name: set alternative (using link parameter)
+    alternatives:
+      name: dummy
+      path: '/usr/bin/dummy{{ item }}'
+      link: '/usr/bin/dummy'
+    register: alternative
+
+  - name: check expected command was executed
+    assert:
+      that:
+        - 'alternative|success'
+        - 'alternative|changed'
+  when: with_link
+
+- block:
+  - name: set alternative (without link parameter)
+    alternatives:
+      name: dummy
+      path: '/usr/bin/dummy{{ item }}'
+    register: alternative
+
+  - name: check expected command was executed
+    assert:
+      that:
+        - 'alternative|success'
+        - 'alternative|changed'
+  when: not with_link
+
+- name: execute dummy command
+  shell: dummy
+  register: cmd
+
+- name: check expected command was executed
+  assert:
+    that:
+      - 'cmd.stdout == "dummy" ~ item'
+
+- name: 'check mode (manual: alternatives file existed, it has been updated)'
+  shell: 'head -n1 {{ alternatives_dir }}/dummy | grep "^manual$"'
+  when: ansible_os_family != 'RedHat' or with_alternatives or item != 1
+
+- name: 'check mode (auto: alternatives file didn''t exist, it has been created)'
+  shell: 'head -n1 {{ alternatives_dir }}/dummy | grep "^auto$"'
+  when: ansible_os_family == 'RedHat' and not with_alternatives and item == 1
+
+- name: check that alternative has been updated
+  command: "grep -Pzq '/bin/dummy{{ item }}\\n' '{{ alternatives_dir }}/dummy'"
+  # priority doesn't seem updated
+  #command: "grep -Pzq '/bin/dummy{{ item }}\\n50' '{{ alternatives_dir }}/dummy'"

test/integration/targets/alternatives/tasks/tests.yml

@@ -0,0 +1,15 @@
+- block:
+  - include_tasks: remove_links.yml
+  - include_tasks: setup_test.yml
+  # at least two iterations:
+  # - first will use 'link currently absent',
+  # - second will receive 'link currently points to'
+  - include_tasks: test.yml
+    with_sequence: start=1 end=2
+  vars:
+    with_link: '{{ test_conf[0] }}'
+    with_alternatives: '{{ test_conf[1] }}'
+    mode: '{{ test_conf[2] }}'
+  # update-alternatives included in Fedora 26 (1.10) & Red Hat 7.4 (1.8) doesn't provide
+  # '--query' switch, 'link' is mandatory for these distributions.
+  when: ansible_os_family != 'RedHat' or test_conf[0]

test/integration/targets/alternatives/tasks/tests_set_priority.yml

@@ -0,0 +1,23 @@
+- name: update dummy alternative
+  alternatives:
+    name: dummy
+    path: '/usr/bin/dummy{{ item }}'
+    link: /usr/bin/dummy
+    priority: '{{ 60 + item|int }}'
+  register: alternative
+
+- name: execute dummy command
+  shell: dummy
+  register: cmd
+
+- name: check if link group is in manual mode
+  shell: 'head -n1 {{ alternatives_dir }}/dummy | grep "^manual$"'
+
+- name: check expected command was executed
+  assert:
+    that:
+      - 'alternative|changed'
+      - 'cmd.stdout == "dummy{{ item }}"'
+
+- name: check that alternative has been updated
+  command: "grep -Pzq '/bin/dummy{{ item }}\\n{{ 60 + item|int }}' '{{ alternatives_dir }}/dummy'"

test/integration/targets/alternatives/templates/dummy_alternative

@@ -0,0 +1,12 @@
+{{ mode }}
+/usr/bin/dummy
+
+{% if with_alternatives %}
+/usr/bin/dummy1
+40
+/usr/bin/dummy2
+30
+
+{% else %}
+
+{% endif %}

test/integration/targets/alternatives/templates/dummy_command

@@ -0,0 +1,2 @@
+#!/bin/sh
+echo dummy{{ item }}

test/integration/targets/alternatives/vars/Debian.yml

@@ -0,0 +1,2 @@
+---
+alternatives_dir: /var/lib/dpkg/alternatives/

test/integration/targets/alternatives/vars/Suse.yml

@@ -0,0 +1,2 @@
+---
+alternatives_dir: /var/lib/rpm/alternatives/

test/integration/targets/alternatives/vars/default.yml

@@ -0,0 +1,2 @@
+---
+alternatives_dir: /var/lib/alternatives/

test/sanity/pep8/legacy-files.txt

@@ -431,7 +431,6 @@ lib/ansible/modules/storage/netapp/sf_volume_access_group_manager.py
 lib/ansible/modules/storage/netapp/sf_volume_manager.py
 lib/ansible/modules/storage/zfs/zfs.py
 lib/ansible/modules/system/aix_inittab.py
-lib/ansible/modules/system/alternatives.py
 lib/ansible/modules/system/at.py
 lib/ansible/modules/system/capabilities.py
 lib/ansible/modules/system/cron.py