I find Google's service auth SO hard to figure out. I've been meaning to solve deploying to Cloud Run via service with for several years now but it just doesn't fit in my brain well enough for me to make the switch.
For deploying, on GitHub I just use a special service account for CI/CD and put the json payload in an environment secret like an API key. The only extra thing is that you need to copy it to the filesystem for some things to work, usually a file named google_application_credentials.json
If you use cloud build you shouldn't need to do anything
Everything is service accounts and workload identity federation, with restrictions such as only letting main branch in specific repo to use it (so no problem with unreviewed PRs getting production access).
Edit: if you have a specific error or issue where this doesn't work for you, and can share the code, I can have a look.
How do you sign a firebase custom auth token with workload identity federation? How about a pre signed storage URL? Off the top of my head I think those were two things that don't work
You have a JSON key file which you can't know how many people have. The person who created the key, downloaded it and then stored it as github secret - did they download it to /dev/shm? Did some npm/brew install script steal it from their downloads folder? Any of the github repo owners can get hold of it. Depending on whether you use github environments/deployments and have set it up properly, so can anyone with write access to the repo. Do you pin all your dependencies, reusable workflows etc, or can a compromise of someone elses repo steal your secrets?
With the workload identity auth, there is no key. Each access obtains a short lived token. Only workflows on main branch can get it. Every run will have audit logs, and so will every action taken by that token. Risk of compromise is much lower, but even more importantly, if compromised I'll be able to know exactly when and how, and what malicious actions were taken.
Maybe this is paranoid to you and not worth it. That's fine. But it's not "no risk", and it is worth to me to protect personal data of our users.
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As for your question, first step is just to run https://github.com/google-github-actions/auth with identity provider configured in your GCP project, restricted to your github repo or org.
This will create application default credentials that most GCP tools and libraries will just work with as if when you are running things locally after "gcloud auth login".
For firebase token you can just run a python script as subsequent step in the github job doing something like https://firebase.google.com/docs/auth/admin/create-custom-to.... For signed storage url this can be done with the gcloud tool: https://cloud.google.com/storage/docs/access-control/signing...
In both cases after running the "google-github-actions/auth" step it will just work with the short-lived credentials that step generated.
And even if you don't ask, there are many examples. But I feel ya. The right example to fit your need is hard to find.
- There are principals. (users, service accounts)
- Each one needs to authenticate, in some way. There are options here. SAML or OIDC or Google Signin for users; other options for service accounts.
- Permissions guard the things you can do in Google cloud.
- There are builtin roles that wrap up sets of permissions.
- you can create your own custom roles.
- attach roles to principals to give them parcels of permissions.
It's not complicated in the context of huge enterprise applications, but for most people trying to use Google's LLMs, it's much more confusing than using an API key. The parent commenter is probably using an aws secret key.
And FWIW this is basically what google encourages you to do with firebase (with the admin service account credential as a secret key).