Docker volume fix labels (#48536)

* Add integration test for labels (which fails).

* Changing labels from list to dict.

* Add changelog.

lib/ansible/modules/cloud/docker/docker_volume.py

@@ -25,6 +25,7 @@ options:
     description:
       - Name of the volume to operate on.
     required: true
+    type: dict
     aliases:
       - volume_name
 
@@ -32,15 +33,18 @@ options:
     description:
       - Specify the type of volume. Docker provides the C(local) driver, but 3rd party drivers can also be used.
     default: local
+    type: str
 
   driver_options:
     description:
       - "Dictionary of volume settings. Consult docker docs for valid options and values:
         U(https://docs.docker.com/engine/reference/commandline/volume_create/#driver-specific-options)"
+    type: dict
 
   labels:
     description:
-      - List of labels to set for the volume
+      - Dictionary of label key/values to set for the volume
+    type: dict
 
   force:
     description:
@@ -185,8 +189,7 @@ class DockerVolumeManager(object):
                         differences.append('driver_options.%s' % key)
         if self.parameters.labels:
             existing_labels = self.existing_volume.get('Labels', {})
-            all_labels = set(self.parameters.labels) | set(existing_labels)
-            for label in all_labels:
+            for label in self.parameters.labels:
                 if existing_labels.get(label) != self.parameters.labels.get(label):
                     differences.append('labels.%s' % label)
 
@@ -247,7 +250,7 @@ def main():
         state=dict(type='str', default='present', choices=['present', 'absent']),
         driver=dict(type='str', default='local'),
         driver_options=dict(type='dict', default={}),
-        labels=dict(type='list'),
+        labels=dict(type='dict'),
         force=dict(type='bool', default=False),
         debug=dict(type='bool', default=False)
     )