GCP PubSub credentials file

[erdody]

We're evaluating using the pubsub output connector. We'd like to get GCP credentials from files (mounted k8s secrets) instead of using env. vars.

We tried:

1. bloblang file function: the credentials_json field is not interpolated
2. cli flags: this doesn't seem to work with the streams mode, which we would also like to use

Is there any way we can achieve this currently?

If not, would you be open to a PR to add a credentials_file field that would just set to the corresponding option (WithCredentialsFile) in google's pubsub client?

[mihaitodor]

Hey @erdody 👋 I think you should be able to use the GOOGLE_APPLICATION_CREDENTIALS environment variable and point it to the mounted JSON file.

[erdody]

Thanks @mihaitodor, that would work if we only had one gcp connector (or all of them used the same credentials). When using streams, it would be nice to be able to control credentials per stream, individually. Would you be open to a PR to add a credentials_file field?

[mihaitodor]

Ahhh, that makes sense. Yes, that sounds like a good addition. Thank you!