TL;DR

Workload identity federation lets a workload on AWS prove its identity to Google Cloud with its IAM role and receive a short-lived GCP token, so no service account key file is stored anywhere.

Bifrost v2.3.0 adds aws_workload_identity to Vertex AI keys: it signs an STS GetCallerIdentity request with the workload's AWS credentials and exchanges it at Google's Security Token Service.

On the GCP side you create a workload identity pool with an AWS provider, restrict it to the Bifrost role, and grant Vertex AI access directly or through an impersonated service account.

On AWS you attach the role with IRSA, EKS Pod Identity, an ECS task role, or an EC2 instance profile, and keep static AWS_ACCESS_KEY_ID values out of the pod.

Workload identity federation is a Google Cloud IAM feature that lets workloads running outside Google Cloud exchange their own identity, such as an AWS IAM role, for short-lived Google credentials instead of using a service account key.…