gcloud: Use DEFAULT_RETRY when uploading a file.

[Hatell]

Use a default retry policy when uploading a file to Google Storage.

[jschneier]

What motivates this change?

[Hatell]

Recently I have had issues with Google Cloud Storage. Some times I got 503 and I had few data losses. GCS documentation says that when server answer 503 you need retry and use retry policy to automate it.

The default retry policy of upload_from_file is DEFAULT_RETRY_IF_GENERATION_SPECIFIED and call of upload_from_file doesn't specify generation so there is no retry.

[jschneier]

Okay, this change looks fine if you fix CI. Will need a rebase.

[Hatell]

Rebase is now done.

[jschneier]

Thanks, can you please fix the tests.

[Hatell]

Now tests are fixed.

[Hatell]

I fixed those flake8 issues.

[jschneier]

@Hatell what do you think about adding retry=DEFAULT_RETRY to .delete()? I think that's now the only place where there are no retries left.

For whatever reason it looks like the client lib uses DEFAULT_RETRY for all readonly operations and DEFAULT_RETRY_IF_GENERATION_SPECIFIED for all write/delete operations.

[Hatell]

I think that adding retry to delete is good idea. Can you do that now? I can do it tomorrow.

[jschneier]

Not sure if I have permissions to push to your branch, will let you do it.

[Hatell]

Retry is added to delete_blob call.