quay/util/migrate/backfill_content_checksums_and_torrent_pieces.py

import logging

from peewee import (JOIN_LEFT_OUTER, CharField, BigIntegerField, BooleanField, ForeignKeyField,
                    IntegerField, IntegrityError, fn)

from data.database import BaseModel, CloseForLongOperation
from data.fields import Base64BinaryField
from app import app, storage
from digest import checksums
from util.migrate.allocator import yield_random_entries
from util.registry.torrent import PieceHasher
from util.registry.filelike import wrap_with_handler


BATCH_SIZE = 1000


logger = logging.getLogger(__name__)


# Vendor the information from tables we will be writing to at the time of this migration
class ImageStorage(BaseModel):
  uuid = CharField(index=True, unique=True)
  checksum = CharField(null=True)
  image_size = BigIntegerField(null=True)
  uncompressed_size = BigIntegerField(null=True)
  uploading = BooleanField(default=True, null=True)
  cas_path = BooleanField(default=True)
  content_checksum = CharField(null=True, index=True)


class ImageStorageLocation(BaseModel):
  name = CharField(unique=True, index=True)


class ImageStoragePlacement(BaseModel):
  storage = ForeignKeyField(ImageStorage)
  location = ForeignKeyField(ImageStorageLocation)


class TorrentInfo(BaseModel):
  storage = ForeignKeyField(ImageStorage)
  piece_length = IntegerField()
  pieces = Base64BinaryField()


def _get_image_storage_locations(storage_id):
  placements_query = (ImageStoragePlacement
                      .select(ImageStoragePlacement, ImageStorageLocation)
                      .join(ImageStorageLocation)
                      .switch(ImageStoragePlacement)
                      .join(ImageStorage, JOIN_LEFT_OUTER)
                      .where(ImageStorage.id == storage_id))

  locations = set()
  for placement in placements_query:
    locations.add(placement.location.name)

  return locations


def _get_layer_path(storage_record):
  """ Returns the path in the storage engine to the layer data referenced by the storage row. """
  if not storage_record.cas_path:
    logger.debug('Serving layer from legacy v1 path: %s', storage_record.uuid)
    return storage.v1_image_layer_path(storage_record.uuid)
  return storage.blob_path(storage_record.content_checksum)


def backfill_content_checksums_and_torrent_pieces(piece_length):
  """ Hashes the entire file for the content associated with an imagestorage. """
  logger.debug('Began execution')
  logger.debug('This may be a long operation!')

  def batch_query():
    return (ImageStorage
            .select(ImageStorage.id, ImageStorage.uuid, ImageStorage.content_checksum,
                    ImageStorage.cas_path)
            .join(TorrentInfo, JOIN_LEFT_OUTER, on=((TorrentInfo.storage == ImageStorage.id) &
                                                    (TorrentInfo.piece_length == piece_length)))
            .where((TorrentInfo.id >> None) | (ImageStorage.content_checksum >> None)))

  max_id = ImageStorage.select(fn.Max(ImageStorage.id)).scalar()

  checksums_written = 0
  pieces_written = 0
  for candidate_storage, abort in yield_random_entries(batch_query, ImageStorage.id, BATCH_SIZE,
                                                       max_id):
    locations = _get_image_storage_locations(candidate_storage.id)

    checksum = ImageStorage.content_checksum
    torrent_pieces = ''
    with CloseForLongOperation(app.config):
      try:
        # Compute the checksum
        layer_path = _get_layer_path(candidate_storage)
        with storage.stream_read_file(locations, layer_path) as layer_data_handle:
          hasher = PieceHasher(piece_length)
          wrapped = wrap_with_handler(layer_data_handle, hasher.update)
          checksum = 'sha256:{0}'.format(checksums.sha256_file(wrapped))
          torrent_pieces = hasher.final_piece_hashes()
      except Exception as exc:
        logger.exception('Unable to compute hashes for storage: %s', candidate_storage.uuid)

        # Create a fallback value for the checksum
        if checksum is None:
          checksum = 'unknown:{0}'.format(exc.__class__.__name__)

    torrent_collision = False
    checksum_collision = False

    # Now update the ImageStorage with the checksum
    num_updated = (ImageStorage
                   .update(content_checksum=checksum)
                   .where(ImageStorage.id == candidate_storage.id,
                          ImageStorage.content_checksum >> None)).execute()
    checksums_written += num_updated
    if num_updated == 0:
      checksum_collision = True

    try:
      TorrentInfo.create(storage=candidate_storage.id, piece_length=piece_length,
                         pieces=torrent_pieces)
      pieces_written += 1
    except IntegrityError:
      torrent_collision = True

    if torrent_collision and checksum_collision:
      logger.info('Another worker pre-empted us for storage: %s', candidate_storage.uuid)
      abort.set()

    if (pieces_written % BATCH_SIZE) == 0 or (checksums_written % BATCH_SIZE) == 0:
      logger.debug('%s checksums written, %s torrent pieces written', checksums_written,
                   pieces_written)

  logger.debug('Completed, %s checksums written, %s torrent pieces written', checksums_written,
               pieces_written)


if __name__ == '__main__':
  logging.basicConfig(level=logging.DEBUG)
  #logging.getLogger('peewee').setLevel(logging.WARNING)
  logging.getLogger('boto').setLevel(logging.WARNING)
  logging.getLogger('data.database').setLevel(logging.WARNING)
  backfill_content_checksums_and_torrent_pieces(app.config['TORRENT_PIECE_SIZE'])