Fix deleting repos and images under MySQL

MySQL doesn't handle constraints at the end of transactions, so deleting images currently fails. This removes the constraint and just leaves parent_id as an int

data/database.py

@@ -575,7 +575,7 @@ class Image(BaseModel):
 
   security_indexed = BooleanField(default=False)
   security_indexed_engine = IntegerField(default=-1)
-  parent = ForeignKeyField('self', index=True, null=True, related_name='children')
+  parent_id = IntegerField(index=True, null=True)
 
   class Meta:
     database = db

data/migrations/versions/57dad559ff2d_add_support_for_quay_s_security_indexer.py

@@ -19,14 +19,13 @@ def upgrade(tables):
     op.add_column('image', sa.Column('security_indexed', sa.Boolean(), nullable=False, default=False, server_default=sa.sql.expression.false()))
     op.add_column('image', sa.Column('security_indexed_engine', sa.Integer(), nullable=False, default=-1, server_default="-1"))
     op.create_index('image_parent_id', 'image', ['parent_id'], unique=False)
-    op.create_foreign_key(op.f('fk_image_parent_id_image'), 'image', 'image', ['parent_id'], ['id'])
     ### end Alembic commands ###
+
     op.create_index('image_security_indexed_engine_security_indexed', 'image', ['security_indexed_engine', 'security_indexed'])
 
 def downgrade(tables):
    ### commands auto generated by Alembic - please adjust! ###
     op.drop_index('image_security_indexed_engine_security_indexed', 'image')
-    op.drop_constraint(op.f('fk_image_parent_id_image'), 'image', type_='foreignkey')
     op.drop_index('image_parent_id', table_name='image')
     op.drop_column('image', 'security_indexed')
     op.drop_column('image', 'security_indexed_engine')

data/model/image.py

@@ -303,7 +303,7 @@ def set_image_metadata(docker_image_id, namespace_name, repository_name, created
 
     if parent:
       fetched.ancestors = '%s%s/' % (parent.ancestors, parent.id)
-      fetched.parent = parent
+      fetched.parent_id = parent.id
 
     fetched.save()
     fetched.storage.save()

data/model/repository.py

@@ -131,12 +131,12 @@ def garbage_collect_repo(repo):
     # iterable of tuples containing [(k, v), (k, v), ...]
     all_repo_images = Image.select(Image.id, Image.storage).where(Image.repository == repo).tuples()
     images_to_storages = dict(all_repo_images)
-    to_remove = set(images_to_storages.keys()).difference(referenced_ancestors)
+    to_remove = list(set(images_to_storages.keys()).difference(referenced_ancestors))
 
     if len(to_remove) > 0:
       logger.info('Cleaning up unreferenced images: %s', to_remove)
       storage_id_whitelist = {images_to_storages[to_remove_id] for to_remove_id in to_remove}
-      Image.delete().where(Image.id << list(to_remove)).execute()
+      Image.delete().where(Image.id << to_remove).execute()
 
   if len(to_remove) > 0:
     logger.info('Garbage collecting storage for images: %s', to_remove)