Refactor of kolla_container_facts

Refactor that prepares kolla_container_facts
module for introducing more actions that will be moved
from kolla_container module and kolla_container_volume_facts.

This change is based on a discussion about adding a new action
to kolla_container module that retrieves all names of the running
containers. It was agreed that kolla-ansible should follow Ansible's
direction of splitting modules between action modules and facts
modules. Because of this, kolla_container_facts needs to be able
to handle different requests for data about containers or volumes.

Change-Id: Ieaec8f64922e4e5a2199db2d6983518b124cb4aa
Signed-off-by: Ivan Halomi <ivan.halomi@tietoevry.com>

1 files changed, 89 insertions, 53 deletions

diff --git a/ansible/library/kolla_container_facts.py b/ansible/library/kolla_container_facts.py
index ef3617db2..7e2254e51 100644
--- a/ansible/library/kolla_container_facts.py
+++ b/ansible/library/kolla_container_facts.py
@@ -12,8 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-
+from abc import ABC
+from abc import abstractmethod
 from ansible.module_utils.basic import AnsibleModule
+from traceback import format_exc
 
 
 DOCUMENTATION = '''
@@ -40,9 +42,9 @@ options:
       - Name or names of the containers
     required: False
     type: str or list
-  container_engine:
+  action:
     description:
-      - Name of container engine to use
+      - The action to perform
     required: True
     type: str
 author: Jeffrey Zhang
@@ -54,6 +56,7 @@ EXAMPLES = '''
     - name: Gather docker facts
       kolla_container_facts:
         container_engine: docker
+      action: get_containers
 
     - name: Gather glance container facts
       kolla_container_facts:
@@ -62,70 +65,103 @@ EXAMPLES = '''
           - glance_api
           - glance_registry
         container_engine: podman
+        action: get_containers
 '''
 
 
-def get_docker_client():
-    import docker
-    return docker.APIClient
-
-
-def use_docker(module, results):
-    client = get_docker_client()(version=module.params.get('api_version'))
-
-    containers = client.containers()
-    names = module.params.get('name')
-    if names and not isinstance(names, list):
-        names = [names]
-    for container in containers:
-        for container_name in container['Names']:
-            # remove '/' prefix character
-            container_name = container_name[1:]
-            if names and container_name not in names:
+class ContainerFactsWorker(ABC):
+    def __init__(self, module):
+        self.module = module
+        self.results = dict(changed=False, _containers=[])
+        self.params = module.params
+
+    @abstractmethod
+    def get_containers(self):
+        pass
+
+
+class DockerFactsWorker(ContainerFactsWorker):
+    def __init__(self, module):
+        super().__init__(module)
+        try:
+            import docker
+        except ImportError:
+            self.module.fail_json(
+                msg="The docker library could not be imported")
+        self.client = docker.APIClient(version=module.params.get(
+                                       'api_version'))
+
+    def get_containers(self):
+        containers = self.client.containers()
+        names = self.params.get('name')
+        if names and not isinstance(names, list):
+            names = [names]
+        for container in containers:
+            for container_name in container['Names']:
+                # remove '/' prefix character
+                container_name = container_name[1:]
+                if names and container_name not in names:
+                    continue
+                self.results['_containers'].append(container)
+                self.results[container_name] = container
+
+
+class PodmanFactsWorker(ContainerFactsWorker):
+    def __init__(self, module):
+        try:
+            import podman.errors as podmanError
+            from podman import PodmanClient
+        except ImportError:
+            self.module.fail_json(
+                msg="The podman library could not be imported")
+        self.podmanError = podmanError
+        super().__init__(module)
+        self.client = PodmanClient(
+            base_url="http+unix:/run/podman/podman.sock")
+
+    def get_containers(self):
+        try:
+            containers = self.client.containers.list(
+                all=True, ignore_removed=True)
+        except self.podmanError.APIError as e:
+            self.module.fail_json(failed=True,
+                                  msg=f"Internal error: {e.explanation}")
+        names = self.params.get('name')
+        if names and not isinstance(names, list):
+            names = [names]
+
+        for container in containers:
+            container.reload()
+            container_name = container.attrs['Name']
+            if container_name not in names:
                 continue
-            results['_containers'].append(container)
-            results[container_name] = container
-
-
-def use_podman(module, results):
-    import podman.errors as pe
-    from podman import PodmanClient
-
-    client = PodmanClient(base_url="http+unix:/run/podman/podman.sock")
-
-    try:
-        containers = client.containers.list(all=True, ignore_removed=True)
-    except pe.APIError as e:
-        module.fail_json(failed=True, msg=f"Internal error: {e.explanation}")
-    names = module.params.get('name')
-    if names and not isinstance(names, list):
-        names = [names]
-
-    for container in containers:
-        container.reload()
-        container_name = container.attrs['Name']
-        if names and container_name not in names:
-            continue
-        results['_containers'].append(container.attrs)
-        results[container_name] = container.attrs
+            self.results['_containers'].append(container.attrs)
+            self.results[container_name] = container.attrs
 
 
 def main():
     argument_spec = dict(
         name=dict(required=False, type='list', default=[]),
         api_version=dict(required=False, type='str', default='auto'),
-        container_engine=dict(required=True, type='str')
+        container_engine=dict(required=True, type='str'),
+        action=dict(required=True, type='str',
+                    choices=['get_containers']),
     )
 
     module = AnsibleModule(argument_spec=argument_spec)
 
-    results = dict(changed=False, _containers=[])
-    if module.params['container_engine'] == 'podman':
-        use_podman(module, results)
-    else:
-        use_docker(module, results)
-
-    module.exit_json(**results)
+    cw: ContainerFactsWorker = None
+    try:
+        if module.params.get('container_engine') == 'docker':
+            cw = DockerFactsWorker(module)
+        else:
+            cw = PodmanFactsWorker(module)
+
+        result = bool(getattr(cw, module.params.get('action'))())
+        module.exit_json(result=result, **cw.results)
+    except Exception:
+        module.fail_json(changed=True, msg=repr(format_exc()),
+                         **getattr(cw, 'result', {}))
 
 
 if __name__ == "__main__":