CI/CD - basics - 1 - CI

CI/CD Plan

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

---

1-1. build image with github action

• set a self hosted machine to run the action(build)
• run an ec2 instance and set up the runner and build tool like docker.(cli install)
  linux type can be get using uname -m command.
• add runner to the repo.
  Commands for that are well described at (repo setting - action - runner -add new runner)
• branch protection rule is also needed.

name: build image and push to ecr
on:
  workflow_dispatch:
  push:
    branches:
      - main
      - dev
      - action-test
    paths:
    - 'testapp/**'
  pull_request:
    paths:
    - 'testapp/**'
  
jobs:
  build-simple-api:
    name: Build and push simple-api image
    environment: dev
    runs-on: [self-hosted, linux, x64]

    steps:
    - uses: actions/checkout@v2
    - run: docker build -t simple-api testapp/ 

This is sample workflow to build.

1-2. push the image to ecr

Building and pushing the image with just action is fine, but skaffold can provide better practice in case of k8s.

Install skaffold to the runner(+ awscli).
And write skaffold file which builds the image -

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:
  #   kubectl:
  #     manifests:
  #     - deploy/k8s/simple-api.yaml

This is simple skaffold setting.
It will build /testapp/Dockerfile using docker and docker buildkt.
More options are in api docs.

To run this skaffold file, workflow file should be modified.

name: build image and push to ecr
on:
  workflow_dispatch:
  push:
    branches:
      - main
      - dev
      - action-test
    paths:
    - 'testapp/**'
  pull_request:
    paths:
    - 'testapp/**'
  
jobs:
  build-simple-api:
    name: Build and push simple-api image
    environment: main
    env:
      region: ap-northeast-1
      BUILD_ENV: main
    runs-on: [self-hosted, linux, x64]

    steps:
    - uses: actions/checkout@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: ${{ env.region }}
    
    - name: Login to Amazon ECR
      id: login-ecr
      uses: aws-actions/amazon-ecr-login@v1

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

More skaffold cli options are in this docs..

The skaffold will deploy app in specified k8s namespaces(-n).
Alsp the profile(-p) setting will be needed in deploy step.

In this case, I specified teh repo uri in workflow file, but it can be specified in skaffold file.

build:
  artifacts:
  - image: {repo uri}/simple-api

Now, if action is triggerd, the image will be built and pushed to ecr repo

Further Improvement
Docker, kubectl, skaffold, awscli auto-install when launch using terraform.

• Automatic auth with ec2 iam metadata <- not working in aws cli.