Update deploy-staging workflow to push to staging cluster

Author: catarak

.github/workflows/deploy-staging.yml

@@ -3,6 +3,12 @@ on:
   push:
     branches:
       - chore/github-actions
+env:
+  PROJECT_ID: ${{ secrets.GKE_PROJECT }}
+  GKE_CLUSTER: p5js-web-editor-cluster
+  GKE_ZONE: us-east1-c
+  DEPLOYMENT_NAME: web-editor-node
+  IMAGE: ${{ secrets.DOCKER_USERNAME }}/p5.js-web-editor-staging
 jobs:
   push_to_registry:
     environment: staging
@@ -25,6 +31,38 @@ jobs:
           file: ./Dockerfile
           pull: true
           push: true
-          tags: ${{ secrets.DOCKER_USERNAME }}/p5.js-web-editor-staging:${{ github.sha }}
+          tags: |
+            $IMAGE:${{ github.sha }}
+            $IMAGE:latest
           target: production
+      # 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: ${{ secrets.GKE_SA_KEY }}
+
+        # Set up kustomize
+      - name: Set up Kustomize
+        run: |-
+          curl -sfLo kustomize https://github.com/kubernetes-sigs/kustomize/releases/download/v3.1.0/kustomize_3.1.0_linux_amd64
+          chmod u+x ./kustomize
+  
+      # Deploy the Docker image to the GKE cluster
+      - name: Deploy
+        run: |-
+          ./kustomize edit set image web-editor-app=index.docker.io/$IMAGE:$GITHUB_SHA --namespace=staging
+          ./kustomize build . | kubectl apply -f -
+          kubectl rollout status deployment/$DEPLOYMENT_NAME --namespace=staging
+          kubectl get services -o wide --namespace=staging