Fix idempotency of docker_compose_v2_pull. (#814)

changelogs/fragments/814-docker_compose_v2_pull-idem.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - "docker_compose_v2_pull - fixing idempotence by checking actual pull progress events instead of service-level pull request when ``policy=always``. This stops the module from reporting ``changed=true`` if no actual change happened when pulling. In check mode, it has to assume that a change happens though (https://github.com/ansible-collections/community.docker/issues/813, https://github.com/ansible-collections/community.docker/pull/814)."

plugins/module_utils/compose_v2.py

@@ -409,6 +409,8 @@ def has_changes(events, ignore_service_pull_events=False):
             if ignore_service_pull_events and event.status in DOCKER_STATUS_PULL:
                 continue
             return True
+        if event.resource_type == ResourceType.IMAGE_LAYER and event.status in DOCKER_PULL_PROGRESS_WORKING:
+            return True
     return False
 
 

plugins/modules/docker_compose_v2.py

@@ -31,6 +31,8 @@ extends_documentation_fragment:
 attributes:
   check_mode:
     support: full
+    details:
+      - In check mode, pulling the image does not result in a changed result.
   diff_mode:
     support: none
 

plugins/modules/docker_compose_v2_pull.py

@@ -29,6 +29,10 @@ extends_documentation_fragment:
 attributes:
   check_mode:
     support: full
+    details:
+      - If O(policy=always), the module will always indicate a change.
+        Docker Compose does not give any information whether pulling would
+        update the image or not.
   diff_mode:
     support: none
 
@@ -131,7 +135,7 @@ class PullManager(BaseComposeManager):
         rc, stdout, stderr = self.client.call_cli(*args, cwd=self.project_src)
         events = self.parse_events(stderr, dry_run=self.check_mode)
         self.emit_warnings(events)
-        self.update_result(result, events, stdout, stderr)
+        self.update_result(result, events, stdout, stderr, ignore_service_pull_events=self.policy != 'missing' and not self.check_mode)
         self.update_failed(result, events, args, stdout, stderr, rc)
         self.cleanup_result(result)
         return result

tests/integration/targets/docker_compose_v2_pull/tasks/tests/pull.yml

@@ -105,6 +105,10 @@
             policy: missing
           register: pull_2
 
+        - name: Make sure image is not around
+          docker_image_remove:
+            name: '{{ docker_test_image_alpine }}'
+
         - name: Pull with policy=always (check)
           docker_compose_v2_pull:
             project_src: '{{ project_src }}'
@@ -118,26 +122,35 @@
             policy: always
           register: pull_3
 
+        - name: Pull with policy=always (check, idempotent)
+          docker_compose_v2_pull:
+            project_src: '{{ project_src }}'
+            policy: always
+          check_mode: true
+          register: pull_4_check
+
+        - name: Pull with policy=always (idempotent)
+          docker_compose_v2_pull:
+            project_src: '{{ project_src }}'
+            policy: always
+          register: pull_4
+
         - assert:
             that:
               - pull_1_check is changed
               - pull_1_check.actions | selectattr('status', 'eq', 'Pulling') | first
-              - pull_1_check.actions | selectattr('status', 'eq', 'Creating') | length == 0
-              - pull_1_check.actions | selectattr('status', 'eq', 'Recreating') | length == 0
               - pull_1 is changed
               - pull_1.actions | selectattr('status', 'eq', 'Pulling') | first
-              - pull_1.actions | selectattr('status', 'eq', 'Creating') | length == 0
-              - pull_1.actions | selectattr('status', 'eq', 'Recreating') | length == 0
               - pull_2_check is not changed
               - pull_2 is not changed
               - pull_3_check is changed
               - pull_3_check.actions | selectattr('status', 'eq', 'Pulling') | first
-              - pull_3_check.actions | selectattr('status', 'eq', 'Creating') | length == 0
-              - pull_3_check.actions | selectattr('status', 'eq', 'Recreating') | length == 0
               - pull_3 is changed
               - pull_3.actions | selectattr('status', 'eq', 'Pulling') | first
-              - pull_3.actions | selectattr('status', 'eq', 'Creating') | length == 0
+              - pull_4_check is changed
-              - pull_3.actions | selectattr('status', 'eq', 'Recreating') | length == 0
+              - pull_4_check.actions | selectattr('status', 'eq', 'Pulling') | first
+              - pull_4 is not changed
+              - pull_4.actions | selectattr('status', 'eq', 'Pulling') | first
 
     - when: docker_compose_version is version('2.22.0', '<')
       block:
@@ -171,17 +184,9 @@
             that:
               - pull_1_check is changed
               - pull_1_check.actions | selectattr('status', 'eq', 'Pulling') | first
-              - pull_1_check.actions | selectattr('status', 'eq', 'Creating') | length == 0
-              - pull_1_check.actions | selectattr('status', 'eq', 'Recreating') | length == 0
               - pull_1 is changed
               - pull_1.actions | selectattr('status', 'eq', 'Pulling') | first
-              - pull_1.actions | selectattr('status', 'eq', 'Creating') | length == 0
-              - pull_1.actions | selectattr('status', 'eq', 'Recreating') | length == 0
               - pull_2_check is changed
               - pull_2_check.actions | selectattr('status', 'eq', 'Pulling') | first
-              - pull_2_check.actions | selectattr('status', 'eq', 'Creating') | length == 0
+              - pull_2 is not changed
-              - pull_2_check.actions | selectattr('status', 'eq', 'Recreating') | length == 0
-              - pull_2 is changed
               - pull_2.actions | selectattr('status', 'eq', 'Pulling') | first
-              - pull_2.actions | selectattr('status', 'eq', 'Creating') | length == 0
-              - pull_2.actions | selectattr('status', 'eq', 'Recreating') | length == 0