Environment details

• OS type and version:
• Python version: Python 3.11.4
• pip version: pip 23.1.2 from /usr/local/lib/python3.11/site-packages/pip (python 3.11)
• google-cloud-storage version: 2.14.0

Steps to reproduce

1. Usage of Blob.upload_from_filename() seems to sometimes encounter a 503 response
2. This seems to result in an immediate failure, despite indications in

   python-storage/google/cloud/storage/retry.py

   Lines 28 to 38 in ae9a53b

   	_RETRYABLE_TYPES = (
   	api_exceptions.TooManyRequests, # 429
   	api_exceptions.InternalServerError, # 500
   	api_exceptions.BadGateway, # 502
   	api_exceptions.ServiceUnavailable, # 503
   	api_exceptions.GatewayTimeout, # 504
   	ConnectionError,
   	requests.ConnectionError,
   	requests_exceptions.ChunkedEncodingError,
   	requests_exceptions.Timeout,
   	)

   that api_exceptions.ServiceUnavailable is a 503 and should be retried.

Code example

https://github.com/google/osv.dev/blob/b705d0d0b7450ce94137624118a2b54a7f719147/docker/exporter/exporter.py#L57-L64

  def upload_single(self, bucket, source_path, target_path):
    """Upload a single file to a bucket."""
    logging.info('Uploading %s', target_path)
    try:
      blob = bucket.blob(target_path)
      blob.upload_from_filename(source_path)
    except Exception as e:
      logging.error('Failed to export: %s', e)

Stack trace

Failed to export: 503 POST https://storage.googleapis.com/upload/storage/v1/b/osv-test-vulnerabilities/o?uploadType=multipart: {
  "error": {
    "code": 503,
    "message": "We encountered an internal error. Please try again.",
    "errors": [
      {
        "message": "We encountered an internal error. Please try again.",
        "domain": "global",
        "reason": "backendError"
      }
    ]
  }
}
: ('Request failed with status code', 503, 'Expected one of', <HTTPStatus.OK: 200>)

Perhaps 503 needs to be added to _ADDITIONAL_RETRYABLE_STATUS_CODES also?