Merge branch 'stable' into devel

* stable: (275 commits)
  Install correct rpm-sign package in RPM builder
  Updating changelog for 3.1 release
  Switch job_type to check from sync when detecting delete_on_update
  use Unicode apostrophes - not single quotes - for French i18n strings
  pin appdirs==1.4.2
  only cancel deps if we can cancel the inv update
  fixing module_name check and adding support for the debug module
  cancel jobs dependent on inv update
  update tests
  CSS tweaks to workflow results panels
  like inventory updates, check if project update deps already processed
  Revert "Merge pull request #5553 from chrismeyersfsu/fix-waiting_blocked"
  Add awx/ui/client/languages to .gitignore
  Delete awx/ui/client/languages/*.json
  refactor based on review
  Add missing permission check.
  Make current_groups a set to easily avoid duplicates, update asgi-amqp requirement
  avoid duplicated related search fields
  Fix workflow audit items
  fixing module name, json blob, and stdout-for-yum-module on host event
  ...

awx/api/metadata.py

@@ -67,7 +67,10 @@ class Metadata(metadata.SimpleMetadata):
         # Indicate if a field has a default value.
         # FIXME: Still isn't showing all default values?
         try:
-            field_info['default'] = field.get_default()
+            default = field.get_default()
+            if field.field_name == 'TOWER_URL_BASE' and default == 'https://towerhost':
+                default = '{}://{}'.format(self.request.scheme, self.request.get_host())
+            field_info['default'] = default
         except serializers.SkipField:
             pass
 
@@ -120,19 +123,20 @@ class Metadata(metadata.SimpleMetadata):
         actions = {}
         for method in {'GET', 'PUT', 'POST'} & set(view.allowed_methods):
             view.request = clone_request(request, method)
+            obj = None
             try:
                 # Test global permissions
                 if hasattr(view, 'check_permissions'):
                     view.check_permissions(view.request)
                 # Test object permissions
                 if method == 'PUT' and hasattr(view, 'get_object'):
-                    view.get_object()
+                    obj = view.get_object()
             except (exceptions.APIException, PermissionDenied, Http404):
                 continue
             else:
                 # If user has appropriate permissions for the view, include
                 # appropriate metadata about the fields that should be supplied.
-                serializer = view.get_serializer()
+                serializer = view.get_serializer(instance=obj)
                 actions[method] = self.get_serializer_info(serializer)
             finally:
                 view.request = request
@@ -167,6 +171,10 @@ class Metadata(metadata.SimpleMetadata):
         return actions
 
     def determine_metadata(self, request, view):
+        # store request on self so we can use it to generate field defaults
+        # (such as TOWER_URL_BASE)
+        self.request = request
+
         metadata = super(Metadata, self).determine_metadata(request, view)
 
         # Add version number in which view was added to Tower.