Raise a 409 if we try to insert a tag twice at the same time

Also fixes handling of labels for existing manifests

Fixes #1775

data/model/tag.py

@@ -2,8 +2,9 @@ import logging
 
 from uuid import uuid4
 
+from peewee import IntegrityError
 from data.model import (image, db_transaction, DataModelException, _basequery,
-                        InvalidManifestException)
+                        InvalidManifestException, TagAlreadyCreatedException)
 from data.database import (RepositoryTag, Repository, Image, ImageStorage, Namespace, TagManifest,
                            RepositoryNotification, Label, TagManifestLabel, get_epoch_timestamp,
                            db_for_update)
@@ -96,8 +97,12 @@ def create_or_update_tag(namespace_name, repository_name, tag_name, tag_docker_i
     except Image.DoesNotExist:
       raise DataModelException('Invalid image with id: %s' % tag_docker_image_id)
 
-    return RepositoryTag.create(repository=repo, image=image_obj, name=tag_name,
-                                lifetime_start_ts=now_ts, reversion=reversion)
+    try:
+      return RepositoryTag.create(repository=repo, image=image_obj, name=tag_name,
+                                  lifetime_start_ts=now_ts, reversion=reversion)
+    except IntegrityError:
+      msg = 'Tag with name %s and lifetime start %s under repository %s/%s already exists'
+      raise TagAlreadyCreatedException(msg % (tag_name, now_ts, namespace_name, repository_name))
 
 
 def create_temporary_hidden_tag(repo, image_obj, expiration_s):
@@ -255,19 +260,16 @@ def revert_tag(repo_obj, tag_name, docker_image_id):
 def store_tag_manifest(namespace, repo_name, tag_name, docker_image_id, manifest_digest,
                        manifest_data):
   """ Stores a tag manifest for a specific tag name in the database. Returns the TagManifest
-      object, as well as a boolean indicating whether the TagManifest was created or updated.
+      object, as well as a boolean indicating whether the TagManifest was created.
   """
   with db_transaction():
     tag = create_or_update_tag(namespace, repo_name, tag_name, docker_image_id)
 
     try:
       manifest = TagManifest.get(digest=manifest_digest)
-      if manifest.tag == tag:
-        return manifest, False
-
       manifest.tag = tag
       manifest.save()
-      return manifest, True
+      return manifest, False
     except TagManifest.DoesNotExist:
       return TagManifest.create(tag=tag, digest=manifest_digest, json_data=manifest_data), True