- Configure runners-ci node pool inline in the cluster resource instead
of using remove_default_node_pool=true, eliminating the
provision-then-delete cycle that added ~5 min to terraform apply
- Remove the separate infra pool; runners-ci is now the only pool on
the critical path of cluster creation
- Set tests-pods pool min_node_count=0 so no node is provisioned at
apply time — nodes scale up only when test pods are scheduled
- Enable spot instances on the tests-pods pool for ~60-91% cost saving
- Add 60 min job timeout to release-tests to bound hung cluster cost
- Add Terraform plugin cache keyed on the lock file to skip provider
re-downloads on subsequent runs (~30-60s saved)
- Install gke-gcloud-auth-plugin via setup-gcloud to fix kubectl auth
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Switch cluster and all node pools from regional to zonal (`europe-west4-b`) to avoid the 40+ minute provisioning time of a regional (multi-zone) cluster. Adds a `zone` variable to the GKE module and cluster config, and updates the workflow's `gcloud get-credentials` call to use `--zone` instead of `--region`.
