Passing GCP service account key to GKE pods

Your main steps are

1. Create a service account.
2. Provide necessary roles for your service account to work with GCS bucket.
3. Save the account key as a Kubernetes Secret.
4. Use the service account to configure and deploy an application.

I believe you got steps 1 and 2 covered. I researched for two examples (1, 2) that might be of some assistance for the remaining steps .