Deploy a new image from Google Cloud Container Builder to Kubernetes, by storing GKE credentials in GCS.

gcb-kubernetes.yaml

steps:
- name: 'gcr.io/cloud-builders/npm'
  args: ['install']
- name: 'gcr.io/cloud-builders/npm'
  args: ['test']
- name: 'gcr.io/cloud-builders/docker'
  args: ["build", "-t", "gcr.io/$PROJECT_ID/frontend:$REVISION_ID", "."]
- name: 'gcr.io/cloud-builders/docker'
  args: ["push", "gcr.io/$PROJECT_ID/frontend:$REVISION_ID"]
- name: 'gcr.io/cloud-builders/gcloud'
  entrypoint: 'bash'
  args:
  - '-c'
  - |
    gcloud components install kubectl
    gsutil cp gs://container-kubernetes-key/kubeconfig .
    export KUBECONFIG=kubeconfig
    kubectl set image deployment/frontend frontend=gcr.io/$PROJECT_ID/frontend:$REVISION_ID