Merge remote-tracking branch 'origin/spartan'

Conflicts:
	test/data/test.db

data/model.py

@@ -755,6 +755,46 @@ def list_repository_tags(namespace_name, repository_name):
   return with_image.where(Repository.name == repository_name,
                           Repository.namespace == namespace_name)
 
+def delete_tag_and_images(namespace_name, repository_name, tag_name):
+  all_images = get_repository_images(namespace_name, repository_name)
+  all_tags = list_repository_tags(namespace_name, repository_name)
+
+  # Find the tag's information.
+  found_tag = None
+  for tag in all_tags:
+    if tag.name == tag_name:
+      found_tag = tag
+      break
+
+  if not found_tag:
+    return
+
+  # Build the set of database IDs corresponding to the tag's ancestor images, as well as the
+  # tag's image itself.
+  tag_image_ids = set(found_tag.image.ancestors.split('/'))
+  tag_image_ids.add(str(found_tag.image.id))
+
+  # Filter out any images that belong to any other tags.
+  for tag in all_tags:
+    if tag.name != tag_name:
+      # Remove all ancestors of the tag.
+      tag_image_ids = tag_image_ids - set(tag.image.ancestors.split('/'))
+
+      # Remove the current image ID.
+      tag_image_ids.discard(str(tag.image.id))
+
+  # Find all the images that belong to the tag.
+  tag_images = [image for image in all_images if str(image.id) in tag_image_ids]
+
+  # Delete the tag found.
+  found_tag.delete_instance()
+
+  # Delete the images found.
+  for image in tag_images:
+    image.delete_instance()
+
+  # TODO: Delete the image's layer data as well.
+
 
 def get_tag_image(namespace_name, repository_name, tag_name):
   joined = Image.select().join(RepositoryTag).join(Repository)