CI/CD - basics - 2 - cd

CI/CD Plan
CI : build and push the image to ecr.
CD : deploy the new image to eks cluster.

---

2-1. Make a helm chart of app.

apiVersion: v1
kind: Service
metadata:
  name: {{ .Values.simpleApiService.serviceName }}
spec:
  selector:
    name: {{ .Values.simpleApiService.serviceName }}
  type: NodePort
  ports:
  - name: http
    protocol: TCP
    nodePort: {{ .Values.simpleApiService.mainPort }}
    port: {{ .Values.simpleApiService.mainPort }}
    targetPort: 8000
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name:  {{ .Values.simpleApiService.serviceName }}
spec:
  replicas: 1
  selector:
    matchLabels:
      name:  {{ .Values.simpleApiService.serviceName }}
  template:
    metadata:
      labels:
        name:  {{ .Values.simpleApiService.serviceName }}
    spec:
      containers:
        - name:  {{ .Values.simpleApiService.serviceName }}
          image : {{ .Values.simpleApiService.image.repository }}:{{ .Values.simpleApiService.image.tag }}
          ports :
            - containerPort: 8000

This is sample helm chart for deploy app.
Istio/ingress setting will be needed.

2-2. Associate the chart and skaffold

apiVersion: skaffold/v3
kind: Config
metadata:
  name: simple-api
build:
  artifacts:
  - image: simple-api
    context: testapp
    # cacheFrom:
    docker:
      dockerfile: Dockerfile

  local:
    useBuildkit: true

profiles:
  - name: main
    deploy:
      helm:
        releases:
          - name: simple-api
            chartPath: deploy/helm/mychart
            valuesFiles: [deploy/helm/mychart/values.yaml]
            wait: true

Add the deploy part on the previous skaffold file.

2-3. modify github action
Install kubectl to runner.

Before deploy pod, check the pod capacity. ec2 instance has default maximum pods .

    steps:
    - uses: actions/checkout@v2
    - uses: FranzDiebold/github-env-vars-action@v2

    - name: Configure AWS credentails
      uses: aws-actions/configure-aws-credentials@v1
      with:
        aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
        aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
        aws-region: ${{ vars.REGION }}
    
    - name: Login to Amazon ECR
      id: login-ecr
      uses: aws-actions/amazon-ecr-login@v1

    - name: get KUBE CONFIG
      id: kubeconfig
      run: aws eks update-kubeconfig --name ${{ vars.EKS_CLUSTER_NAME }} --role ${{ vars.EKS_CLUSTER_ACCESS_ARN }}

    - name: Create namespace
      continue-on-error: true
      run: kubectl create ns $CI_ACTION_REF_NAME_SLUG || echo "Already created or failed!"

    - name: Skaffold appy
      id: skaffold-apply
      run: skaffold run -n $CI_ACTION_REF_NAME_SLUG -f deploy/skaffold/simple-api.yaml --default-repo {ecr repo} -p ${{ env.BUILD_ENV }}

Add the kubeconfig step to get a target cluster and change the skaffold command build -> run(build + deploy).

Now, if the action is triggerd, app is build and deployed to target cluster.