Merge pull request #685 from coreos-inc/fixmigration

write None if we cannot find the json

util/migrate/backfill_v1_metadata.py

@@ -51,7 +51,11 @@ def backfill_v1_metadata():
           json_path = storage.image_json_path(uuid)
 
           logger.debug('Updating image: %s from: %s', repo_image.id, json_path)
+          try:
             data = storage.get_content(repo_image.storage.locations, json_path)
+          except IOError:
+            data = None
+            logger.exception('failed to find v1 metadata, defaulting to None')
           repo_image.v1_json_metadata = data
           repo_image.save()
         except ImageStoragePlacement.DoesNotExist: