Note: GitHub Actions is currently in beta for GitHub AE.
Introduction
This guide explains how to use GitHub Actions to build a containerized application, push it to Google Container Registry (GCR), and deploy it to Google Kubernetes Engine (GKE).
GKE is a managed Kubernetes cluster service from Google Cloud that can host your containerized workloads in the cloud or in your own datacenter. For more information, see Google Kubernetes Engine.
Prerequisites
Before you proceed with creating the workflow, you will need to complete the following steps for your Kubernetes project. This guide assumes the root of your project already has a Dockerfile
and a Kubernetes Deployment configuration file. For an example, see google-github-actions.
Creating a GKE cluster
To create the GKE cluster, you will first need to authenticate using the gcloud
CLI. For more information on this step, see the following articles:
For example:
$ gcloud container clusters create $GKE_CLUSTER \
--project=$GKE_PROJECT \
--zone=$GKE_ZONE
Enabling the APIs
Enable the Kubernetes Engine and Container Registry APIs. For example:
$ gcloud services enable \
containerregistry.googleapis.com \
container.googleapis.com
Configuring a service account and storing its credentials
This procedure demonstrates how to create the service account for your GKE integration. It explains how to create the account, add roles to it, retrieve its keys, and store them as a base64-encoded encrypted repository secret named GKE_SA_KEY
.
-
Create a new service account:
$ gcloud iam service-accounts create $SA_NAME
-
Retrieve the email address of the service account you just created:
$ gcloud iam service-accounts list
-
Add roles to the service account. Note: Apply more restrictive roles to suit your requirements.
$ gcloud projects add-iam-policy-binding $GKE_PROJECT \ --member=serviceAccount:$SA_EMAIL \ --role=roles/container.admin \ --role=roles/storage.admin
-
Download the JSON keyfile for the service account:
$ gcloud iam service-accounts keys create key.json --iam-account=$SA_EMAIL
-
Store the project ID as a secret named
GKE_PROJECT
:$ export GKE_SA_KEY=$(cat key.json | base64)
(Optional) Configuring kustomize
Kustomize is an optional tool used for managing YAML specs. After creating a kustomization file, the workflow below can be used to dynamically set fields of the image and pipe in the result to kubectl
. For more information, see kustomize usage.
Creating the workflow
Once you've completed the prerequisites, you can proceed with creating the workflow.
The following example workflow demonstrates how to build a container image and push it to GCR. It then uses the Kubernetes tools (such as kubectl
and kustomize
) to pull the image into the cluster deployment.
name: Build and Deploy to GKE
on:
release:
types: [created]
env:
PROJECT_ID: ${{ secrets.GKE_PROJECT }}
GKE_CLUSTER: cluster-1 # Add your cluster name here.
GKE_ZONE: us-central1-c # Add your cluster zone here.
DEPLOYMENT_NAME: gke-test # Add your deployment name here.
IMAGE: static-site
jobs:
setup-build-publish-deploy:
name: Setup, Build, Publish, and Deploy
runs-on: ubuntu-latest
steps:
- name: Checkout
uses: actions/checkout@v2
# Setup gcloud CLI
- uses: google-github-actions/setup-gcloud@v0.2.0
with:
service_account_key: ${{ secrets.GKE_SA_KEY }}
project_id: ${{ secrets.GKE_PROJECT }}
# Configure docker to use the gcloud command-line tool as a credential helper
- run: |-
gcloud --quiet auth configure-docker
# Get the GKE credentials so we can deploy to the cluster
- uses: google-github-actions/get-gke-credentials@v0.2.1
with:
cluster_name: ${{ env.GKE_CLUSTER }}
location: ${{ env.GKE_ZONE }}
credentials: ${{ secrets.GKE_SA_KEY }}
# Build the Docker image
- name: Build
run: |-
docker build \
--tag "gcr.io/$PROJECT_ID/$IMAGE:$GITHUB_SHA" \
--build-arg GITHUB_SHA="$GITHUB_SHA" \
--build-arg GITHUB_REF="$GITHUB_REF" \
.
# Push the Docker image to Google Container Registry
- name: Publish
run: |-
docker push "gcr.io/$PROJECT_ID/$IMAGE:$GITHUB_SHA"
# Set up kustomize
- name: Set up Kustomize
run: |-
curl -sfLo kustomize https://github.com/kubernetes-sigs/kustomize/releases/download/v3.1.0/kustomize_3.1.0_linux_amd64
chmod u+x ./kustomize
# Deploy the Docker image to the GKE cluster
- name: Deploy
run: |-
./kustomize edit set image gcr.io/PROJECT_ID/IMAGE:TAG=gcr.io/$PROJECT_ID/$IMAGE:$GITHUB_SHA
./kustomize build . | kubectl apply -f -
kubectl rollout status deployment/$DEPLOYMENT_NAME
kubectl get services -o wide
Additional resources
For more information on the tools used in these examples, see the following documentation:
- For the full starter workflow, see the "Build and Deploy to GKE" workflow.
- For more starter workflows and accompanying code, see Google's GitHub Actions example workflows.
- The Kubernetes YAML customization engine: Kustomize.
- "Deploying a containerized web application" in the Google Kubernetes Engine documentation.