René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Add RefreshError to retryable errors","articleBody":"Thanks for stopping by to let us know something could be better!\r\n\r\n**PLEASE READ**: If you have a support contract with Google, please create an issue in the [support console](https://cloud.google.com/support/) instead of filing on GitHub. This will ensure a timely response.\r\n\r\n **Is your feature request related to a problem? Please describe.**\r\n`RefreshError` can be raised if GCE metadata server returns 500 error for service account token. But, we currently retry only for `TransportError` at [retry.py](https://github.com/googleapis/python-api-core/blob/v2.2.2/google/api_core/retry.py#L106).\r\n\r\nThis makes GCP libraries depending on the default retry fail by the transient auth error.\r\n\r\n **Describe the solution you'd like**\r\nAdd `auth_exceptions.RefreshError` to `if_transient_error`.\r\n\r\n **Describe alternatives you've considered**\r\nCore API users can use a custom retry that handles `RefreshError` as retryable.\r\n\r\n **Additional context**\r\nSee [this screenshot](https://gist.githubusercontent.com/baeminbo/8764d92c01101aa2276e11273fadca7b/raw/e4aae7e369c3d59800cc54ee234aee44ab8d596c/refresh_error.png) of a RefreshError example that happened at GCS API in a Dataflow job.\r\n\r\n","author":{"url":"https://github.com/baeminbo","@type":"Person","name":"baeminbo"},"datePublished":"2021-11-24T15:04:12.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":4},"url":"https://github.com/312/python-api-core/issues/312"}