Add ability to revert tags via time machine

data/database.py

@@ -497,6 +497,7 @@ class RepositoryTag(BaseModel):
   lifetime_start_ts = IntegerField(default=get_epoch_timestamp)
   lifetime_end_ts = IntegerField(null=True, index=True)
   hidden = BooleanField(default=False)
+  reversion = BooleanField(default=False)
 
   class Meta:
     database = db

data/migrations/versions/1c3decf6b9c4_add_revert_tag_log_entry_kind.py

@@ -0,0 +1,29 @@
+"""Add revert_tag log entry kind
+
+Revision ID: 1c3decf6b9c4
+Revises: 4ce2169efd3b
+Create Date: 2015-04-16 17:14:11.154856
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '1c3decf6b9c4'
+down_revision = '4ce2169efd3b'
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def upgrade(tables):
+    op.bulk_insert(tables.logentrykind,
+    [
+        {'id': 47, 'name':'revert_tag'},
+    ])
+
+
+def downgrade(tables):
+    op.execute(
+        (tables.logentrykind.delete()
+            .where(tables.logentrykind.c.name == op.inline_literal('revert_tag')))
+
+    )

data/migrations/versions/4ce2169efd3b_add_reversion_column_to_the_tags_table.py

@@ -0,0 +1,26 @@
+"""Add reversion column to the tags table
+
+Revision ID: 4ce2169efd3b
+Revises: 2b4dc0818a5e
+Create Date: 2015-04-16 17:10:16.039835
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '4ce2169efd3b'
+down_revision = '2b4dc0818a5e'
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def upgrade(tables):
+    ### commands auto generated by Alembic - please adjust! ###
+    op.add_column('repositorytag', sa.Column('reversion', sa.Boolean(), nullable=False))
+    ### end Alembic commands ###
+
+
+def downgrade(tables):
+    ### commands auto generated by Alembic - please adjust! ###
+    op.drop_column('repositorytag', 'reversion')
+    ### end Alembic commands ###

data/model/legacy.py

@@ -1762,13 +1762,17 @@ def _tag_alive(query, now_ts=None):
                      (RepositoryTag.lifetime_end_ts > now_ts))
 
 
-def list_repository_tag_history(repository, limit=100):
+def list_repository_tag_history(repository, limit=100, specific_tag=None):
   query = (RepositoryTag
            .select(RepositoryTag, Image)
            .join(Image)
            .where(RepositoryTag.repository == repository)
            .order_by(RepositoryTag.lifetime_start_ts.desc())
            .limit(limit))
+
+  if specific_tag:
+    query = query.where(RepositoryTag.name == specific_tag)
+
   return query
 
 
@@ -1990,7 +1994,7 @@ def get_parent_images(namespace_name, repository_name, image_obj):
 
 
 def create_or_update_tag(namespace_name, repository_name, tag_name,
-                         tag_docker_image_id):
+                         tag_docker_image_id, reversion=False):
   try:
     repo = _get_repository(namespace_name, repository_name)
   except Repository.DoesNotExist:
@@ -2015,7 +2019,7 @@ def create_or_update_tag(namespace_name, repository_name, tag_name,
       raise DataModelException('Invalid image with id: %s' % tag_docker_image_id)
 
     return RepositoryTag.create(repository=repo, image=image, name=tag_name,
-                                lifetime_start_ts=now_ts)
+                                lifetime_start_ts=now_ts, reversion=reversion)
 
 def delete_tag(namespace_name, repository_name, tag_name):
   now_ts = get_epoch_timestamp()
@@ -2823,3 +2827,14 @@ def repository_is_starred(user, repository):
     return True
   except Star.DoesNotExist:
     return False
+
+
+def revert_tag(namespace_name, repository_name, tag_name, docker_image_id):
+  """ Reverts a tag to a specific image ID. """
+  image = get_image_by_id(namespace_name, repository_name, docker_image_id)
+  if image is None:
+    raise DataModelException('Cannot revert to unknown image')
+
+  return create_or_update_tag(namespace_name, repository_name, tag_name, docker_image_id,
+                              reversion=True)
+