Add check_files_existing option. (#839)

changelogs/fragments/839-compose_v2-check-file.yml

@@ -0,0 +1,6 @@
+minor_changes:
+  - "docker_compose_v2* - the new option ``check_files_existing`` allows to disable the check for one of the files
+    ``compose.yaml``, ``compose.yml``, ``docker-compose.yaml``, and ``docker-compose.yml`` in ``project_src``
+    if ``files`` is not specified. This is necessary if a non-standard compose filename is specified through other
+    means, like the ``COMPOSE_FILE`` environment variable
+    (https://github.com/ansible-collections/community.docker/issues/838, https://github.com/ansible-collections/community.docker/pull/839)."

plugins/doc_fragments/compose_v2.py

@@ -55,6 +55,17 @@ class ModuleDocFragment(object):
           - Equivalent to C(docker compose --profile).
         type: list
         elements: str
+    check_files_existing:
+        description:
+          - If set to V(false), the module will not check whether one of the files
+            C(compose.yaml), C(compose.yml), C(docker-compose.yaml), or C(docker-compose.yml)
+            exists in O(project_src) if O(files) is not provided.
+          - This can be useful if environment files with C(COMPOSE_FILE) are used to configure a different
+            filename. The module currently does not check for C(COMPOSE_FILE) in environment files or the
+            current environment.
+        type: bool
+        default: true
+        version_added: 3.9.0
 requirements:
   - "PyYAML if O(definition) is used"
 notes:

plugins/module_utils/compose_v2.py

@@ -507,6 +507,7 @@ def common_compose_argspec():
         definition=dict(type='dict'),
         env_files=dict(type='list', elements='path'),
         profiles=dict(type='list', elements='str'),
+        check_files_existing=dict(type='bool', default=True),
     )
 
 
@@ -584,12 +585,13 @@ def __init__(self, client, min_version=MINIMUM_COMPOSE_VERSION):
         if not os.path.isdir(self.project_src):
             self.fail('"{0}" is not a directory'.format(self.project_src))
 
+        self.check_files_existing = parameters['check_files_existing']
         if self.files:
             for file in self.files:
                 path = os.path.join(self.project_src, file)
                 if not os.path.exists(path):
                     self.fail('Cannot find Compose file "{0}" relative to project directory "{1}"'.format(file, self.project_src))
-        elif all(not os.path.exists(os.path.join(self.project_src, f)) for f in DOCKER_COMPOSE_FILES):
+        elif self.check_files_existing and all(not os.path.exists(os.path.join(self.project_src, f)) for f in DOCKER_COMPOSE_FILES):
             filenames = ', '.join(DOCKER_COMPOSE_FILES[:-1])
             self.fail('"{0}" does not contain {1}, or {2}'.format(self.project_src, filenames, DOCKER_COMPOSE_FILES[-1]))