Add a script for verifying the placements of blobs in storage. If a blob is not present in storage, its placement will be removed.

util/verifyplacements.py

@@ -0,0 +1,76 @@
+"""
+Usage (from the root in the container): venv/bin/python -m util.verifyplacements
+
+This script verifies that if a blob is listed as being in a specific storage location, the file
+actually exists there. If the file is not found in that storage location, the placement entry in
+the database is removed.
+"""
+
+import logging
+import features
+
+from peewee import fn
+
+from app import storage
+from data import model
+from data.database import ImageStorage, ImageStoragePlacement, ImageStorageLocation
+from util.migrate.allocator import yield_random_entries
+
+logger = logging.getLogger(__name__)
+
+LOCATION_MAP = {}
+
+
+def _get_location_row(location):
+  if location in LOCATION_MAP:
+    return LOCATION_MAP[location]
+  
+  location_row = ImageStorageLocation.get(name=location)
+  LOCATION_MAP[location] = location_row
+  return location_row
+
+
+def verify_placements():
+  encountered = set()
+
+  iterator = yield_random_entries(
+    lambda: ImageStorage.select().where(ImageStorage.uploading == False),
+    ImageStorage.id,
+    1000,
+    ImageStorage.select(fn.Max(ImageStorage.id)).scalar(),
+    1,
+  )
+
+  for storage_row, abt, _ in iterator:
+    if storage_row.id in encountered:
+      continue
+
+    encountered.add(storage_row.id)
+
+    logger.info('Checking placements for storage `%s`', storage_row.uuid)
+    try:
+      with_locations = model.storage.get_storage_by_uuid(storage_row.uuid)
+    except model.InvalidImageException:
+      logger.exception('Could not find storage `%s`', storage_row.uuid)
+      continue
+
+    storage_path = model.storage.get_layer_path(storage_row)
+    locations_to_check = set(with_locations.locations)
+    if locations_to_check:
+      logger.info('Checking locations `%s` for storage `%s`', locations_to_check, storage_row.uuid)
+      for location in locations_to_check:
+        logger.info('Checking location `%s` for storage `%s`', location, storage_row.uuid)
+        if not storage.exists([location], storage_path):
+          location_row = _get_location_row(location)
+          logger.info('Location `%s` is missing for storage `%s`; removing', location,
+                      storage_row.uuid)
+          (ImageStoragePlacement
+           .delete()
+           .where(ImageStoragePlacement.storage == storage_row,
+                  ImageStoragePlacement.location == location_row)
+           .execute())
+
+
+if __name__ == '__main__':
+  logging.basicConfig(level=logging.INFO)
+  verify_placements()