Cloudbuild config for automating deployments to Kubernetes using Helm.

cloudbuild.yml

steps:
- name: 'gcr.io/cloud-builders/git'
  # Determine if the commit that triggered this build includes a directive to destroy a previously created environment
  # If so, write a file as a flag for conditional future steps, always return true to allow build to continue
  entrypoint: '/bin/bash'
  args:
  - '-c'
  - 'git log -n 1 --pretty=format:%s $COMMIT_SHA | grep -q "\[helm\-delete\]" && touch /workspace/helm_delete || true'

- name: 'gcr.io/cloud-builders/docker'
  entrypoint: '/bin/bash'
  args:
  - '-c'
  - |
    if [ -f /workspace/helm_delete ]
    then
      # Pull the existing image so the "images" directive of this file works as expected
      docker pull gcr.io/$PROJECT_ID/application_base:$BRANCH_NAME
    else
      # Otherwise build a new image, using a cache, and then push it so it's available in subsequent steps
      docker pull gcr.io/$PROJECT_ID/application_base:$_CACHE_IMAGE_TAG
      docker build --cache-from gcr.io/$PROJECT_ID/application_base:$_CACHE_IMAGE_TAG -t gcr.io/$PROJECT_ID/application_base:$BRANCH_NAME .
      docker push gcr.io/$PROJECT_ID/application_base:$BRANCH_NAME
    fi

- name: 'gcr.io/cloud-builders/gcloud'
  entrypoint: '/bin/bash'
  args:
  - '-c'
  - |
    gcloud container clusters get-credentials cluster-1 --zone us-west1-a --project $PROJECT_ID
    kubectl version #hack to properly init credentials
    cp ~/.kube/config /workspace/kubeconfig

- name: 'gcr.io/cloud-builders/docker'
  args:
  - run
  - '-e'
  - 'KUBECONFIG=/root/app/kubeconfig'
  - '-e'
  - 'TILLER_NAMESPACE=kube-system'
  - '-v'
  - '/workspace:/root/app'
  - '--entrypoint'
  - '/bin/sh'
  - 'linkyard/docker-helm'
  - '-c'
  - |
    /bin/helm init --client-only &&
    {
      if [ -f /root/app/helm_delete ]
      then
        /bin/helm delete --purge --debug $BRANCH_NAME
      else
        /bin/helm upgrade --install --recreate-pods --timeout 1500 --wait --debug --set image="gcr.io/${PROJECT_ID}/application_base:${BRANCH_NAME}" $BRANCH_NAME /root/app/k8s/helm
      fi
    }

images: ['gcr.io/$PROJECT_ID/application_base:$BRANCH_NAME']
timeout: 1500s

I wanted to use Google's Cloud Container Builder to automate Kubernetes deployments using Helm, and this is what I ended up with.

I'm currently using a build trigger to catch pushes to branches with a name like /.+\-test-env/ to build or update test environments.

An environment is destroyed when a commit containing [helm-delete] is pushed to the corresponding branch.

This also relies on the linkyard/docker-helm image.