Google Kubernetes Engine

GKE pods authenticate with the service account they run as.

Identity proof

The token has to come from https://container.googleapis.com/v1/projects/acme-prod/locations/us-central1/clusters/api, and its sub claim has to match the workload you named. We compare that claim byte for byte, with no wildcards.

Every token also has to name your workspace as its audience. Ask for this audience and no other. A token requested for two audiences fails every exchange.

Console fields

The console also asks which project and environment this identity reaches and which role it gets, with the credential lifetime behind Advanced.

Trust

Built from the example answers above:

We name the identity for you, so the form never asks for one.

Console snippet

volumes:
  - name: penv-token
    projected:
      sources:
        - serviceAccountToken:
            path: token
            # Ask for this audience and no other. A token requested for two audiences fails every exchange.
            audience: YOUR_WORKSPACE_ID
            expirationSeconds: 3600

containers:
  - name: api
    volumeMounts:
      # Without this the volume above exists and no container can read it.
      - name: penv-token
        mountPath: /var/run/secrets/penv
        readOnly: true

# in the container:
#   T=$(cat /var/run/secrets/penv/token)
#   C=$(T="$T" jq -n '{token:env.T}' | curl -sS "https://penv.cloud/api/v1/auth/oidc" \
#     -H 'content-type: application/json' --data-binary @- | jq -r .credential)
#   PENV_TOKEN="$C" penv pull

The snippet finishes with penv pull, which writes a file. We recommend penv run for a process; penv pull is for a host that needs a file on disk. Connect your CI has the wrapped step.

Related

• Machine identity
• Connect a Platform in the console
• Google Kubernetes Engine documentation: the subject is the value most often set wrong