Add ability to revert tags via time machine

endpoints/api/tag.py

@@ -2,7 +2,7 @@ from flask import request, abort
 
 from endpoints.api import (resource, nickname, require_repo_read, require_repo_write,
                            RepositoryParamResource, log_action, NotFound, validate_json_request,
-                           path_param, format_date)
+                           path_param, format_date, parse_args, query_param)
 from endpoints.api.image import image_view
 from data import model
 from auth.auth_context import get_authenticated_user
@@ -17,8 +17,11 @@ class ListRepositoryTags(RepositoryParamResource):
   """ Resource for listing repository tags. """
 
   @require_repo_write
+  @parse_args
+  @query_param('specificTag', 'Filters the tags to the specific tag.', type=str, default='')
+  @query_param('limit', 'Limit to the number of results to return. Max 100.', type=int, default=50)
   @nickname('listRepoTags')
-  def get(self, namespace, repository):
+  def get(self, args, namespace, repository):
     repo = model.get_repository(namespace, repository)
     if not repo:
       abort(404)
@@ -27,6 +30,7 @@ class ListRepositoryTags(RepositoryParamResource):
       tag_info = {
         'name': tag.name,
         'docker_image_id': tag.image.docker_image_id,
+        'reversion': tag.reversion,
       }
 
       if tag.lifetime_start_ts > 0:
@@ -37,7 +41,9 @@ class ListRepositoryTags(RepositoryParamResource):
 
       return tag_info
 
-    tags = model.list_repository_tag_history(repo, limit=100)
+    specific_tag = args.get('specificTag') or None
+    limit = min(100, max(1, args.get('limit', 50)))
+    tags = model.list_repository_tag_history(repo, limit=limit, specific_tag=specific_tag)
     return {'tags': [tag_view(tag) for tag in tags]}
 
 
@@ -134,3 +140,54 @@ class RepositoryTagImages(RepositoryParamResource):
     return {
       'images': [image_view(image, image_map) for image in all_images]
     }
+
+
+
+@resource('/v1/repository/<repopath:repository>/tag/<tag>/revert')
+@path_param('repository', 'The full path of the repository. e.g. namespace/name')
+@path_param('tag', 'The name of the tag')
+class RevertTag(RepositoryParamResource):
+  """ Resource for reverting a repository tag back to a previous image. """
+  schemas = {
+    'RevertTag': {
+      'id': 'RevertTag',
+      'type': 'object',
+      'description': 'Reverts a tag to a specific image',
+      'required': [
+        'image',
+      ],
+      'properties': {
+        'image': {
+          'type': 'string',
+          'description': 'Image identifier to which the tag should point',
+        },
+      },
+    },
+  }
+
+  @require_repo_write
+  @nickname('revertTag')
+  @validate_json_request('RevertTag')
+  def post(self, namespace, repository, tag):
+    """ Reverts a repository tag back to a previous image in the repository. """
+    try:
+      tag_image = model.get_tag_image(namespace, repository, tag)
+    except model.DataModelException:
+      raise NotFound()
+
+    # Revert the tag back to the previous image.
+    image_id = request.get_json()['image']
+    model.revert_tag(namespace, repository, tag, image_id)
+    model.garbage_collect_repository(namespace, repository)
+
+    # Log the reversion.
+    username = get_authenticated_user().username
+    log_action('revert_tag', namespace,
+               {'username': username, 'repo': repository, 'tag': tag,
+                'image': image_id, 'original_image': tag_image.docker_image_id},
+                repo=model.get_repository(namespace, repository))
+
+    return {
+      'image_id': image_id,
+      'original_image_id': tag_image.docker_image_id
+    }