Add worker to backfill the new manifest tables from the tagmanifest table

workers/manifestbackfillworker.py

@@ -0,0 +1,155 @@
+import logging
+import logging.config
+
+from peewee import JOIN, fn, IntegrityError
+
+from app import app
+from data.database import (UseThenDisconnect, TagManifest, TagManifestToManifest, Image,
+                           db_transaction)
+from data.model.tag import populate_manifest
+from image.docker.schema1 import (DockerSchema1Manifest, ManifestException, ManifestInterface,
+                                  DOCKER_SCHEMA1_SIGNED_MANIFEST_CONTENT_TYPE)
+from workers.worker import Worker
+from util.log import logfile_path
+from util.migrate.allocator import yield_random_entries
+
+logger = logging.getLogger(__name__)
+
+class BrokenManifest(ManifestInterface):
+  """ Implementation of the ManifestInterface for "broken" manifests. This allows us to add the
+      new manifest row while not adding any additional rows for it.
+  """
+  def __init__(self, digest, payload):
+    self._digest = digest
+    self._payload = payload
+
+  @property
+  def digest(self):
+    return self._digest
+
+  @property
+  def media_type(self):
+    return DOCKER_SCHEMA1_SIGNED_MANIFEST_CONTENT_TYPE
+
+  @property
+  def manifest_dict(self):
+    return {}
+
+  @property
+  def bytes(self):
+    return self._payload
+
+  @property
+  def layers(self):
+    return []
+
+  @property
+  def leaf_layer_v1_image_id(self):
+    return None
+
+  @property
+  def blob_digests(self):
+    return []
+
+
+class ManifestBackfillWorker(Worker):
+  def __init__(self):
+    super(ManifestBackfillWorker, self).__init__()
+    self.add_operation(self._backfill_manifests, 1)
+
+  def _candidates_to_backfill(self):
+    def missing_tmt_query():
+      return (TagManifest
+              .select()
+              .join(TagManifestToManifest, JOIN.LEFT_OUTER)
+              .where(TagManifestToManifest.id >> None))
+
+    min_id = (TagManifest
+              .select(fn.Min(TagManifest.id))
+              .join(TagManifestToManifest, JOIN.LEFT_OUTER)
+              .where(TagManifestToManifest.id >> None)
+              .scalar())
+    max_id = TagManifest.select(fn.Max(TagManifest.id)).scalar()
+
+    iterator = yield_random_entries(
+      missing_tmt_query,
+      TagManifest.id,
+      100,
+      max_id,
+      min_id,
+    )
+
+    return iterator
+
+  def _backfill_manifests(self):
+    """ Performs garbage collection on repositories. """
+    with UseThenDisconnect(app.config):
+      iterator = self._candidates_to_backfill()
+      if iterator is None:
+        logger.debug('Found no additional images to scan')
+        return None
+
+      for candidate, abt, _ in iterator:
+        if not backfill_manifest(candidate):
+          logger.info('Another worker pre-empted us for manifest: %s', candidate.id)
+          abt.set()
+
+
+def lookup_map_row(tag_manifest):
+  try:
+    TagManifestToManifest.get(tag_manifest=tag_manifest)
+    return True
+  except TagManifestToManifest.DoesNotExist:
+    return False
+
+
+def backfill_manifest(tag_manifest):
+  logger.info('Backfilling manifest %s', tag_manifest.id)
+
+  # Ensure that a mapping row doesn't already exist. If it does, we've been preempted.
+  if lookup_map_row(tag_manifest):
+    return False
+
+  # Parse the manifest. If we cannot parse, then we treat the manifest  as broken and just emit it
+  # without additional rows or data, as it will eventually not be useful.
+  is_broken = False
+  try:
+    manifest = DockerSchema1Manifest(tag_manifest.json_data, validate=False)
+  except ManifestException:
+    logger.exception('Exception when trying to parse manifest %s', tag_manifest.id)
+    manifest = BrokenManifest(tag_manifest.digest, tag_manifest.json_data)
+    is_broken = True
+
+  # Lookup the storages for the digests.
+  root_image = tag_manifest.tag.image
+  storage_id_map = {root_image.storage.content_checksum: root_image.storage.id}
+  for parent_image_id in root_image.ancestor_id_list():
+    storage = Image.get(id=parent_image_id).storage
+    storage_id_map[storage.content_checksum] = storage.id
+
+  with db_transaction():
+    # Re-retrieve the tag manifest to ensure it still exists and we're pointing at the correct tag.
+    try:
+      tag_manifest = TagManifest.get(id=tag_manifest.id)
+    except TagManifest.DoesNotExist:
+      return True
+
+    # Create the new-style rows for the manifest.
+    manifest_row = populate_manifest(tag_manifest.tag.repository, manifest,
+                                     tag_manifest.tag.image, storage_id_map)
+
+    # Create the mapping row. If we find another was created for this tag manifest in the
+    # meantime, then we've been preempted.
+    try:
+      TagManifestToManifest.create(tag_manifest=tag_manifest, manifest=manifest_row,
+                                   broken=is_broken)
+      return True
+    except IntegrityError:
+      return False
+
+
+
+if __name__ == "__main__":
+  logging.config.fileConfig(logfile_path(debug=False), disable_existing_loggers=False)
+  worker = ManifestBackfillWorker()
+  worker.start()