Blue-Green Deploy to AWS EC2

blue-green.yaml

name: Blue-Green Deploy to AWS EC2

on:
  push:
    branches: [ main ]

jobs:
  deploy:
    runs-on: ubuntu-latest

    env:
      CURRENT_COLOR: blue
      NEW_COLOR: green

    steps:
    - uses: actions/checkout@v3

    - name: Set up JDK 11
      uses: actions/setup-java@v3
      with:
        java-version: 11

    - name: Grant execute permission to Gradlew
      run: chmod +x ./gradlew

    - name: Build project
      run: ./gradlew clean build

    - name: Copy JAR file to EC2 instance
      uses: appleboy/scp-action@master
      with:
        host: ${{ secrets.EC2_HOST }}
        username: ${{ secrets.EC2_USER }}
        key: ${{ secrets.EC2_KEY }}
        port: ${{ secrets.EC2_PORT }}
        source: ./build/libs/my-project.jar
        target: /home/ec2-user/my-project-${{ env.NEW_COLOR }}.jar

    - name: SSH into EC2 instance and start new application
      uses: appleboy/ssh-action@master
      with:
        host: ${{ secrets.EC2_HOST }}
        username: ${{ secrets.EC2_USER }}
        key: ${{ secrets.EC2_KEY }}
        port: ${{ secrets.EC2_PORT }}
        script: |
          cd /home/ec2-user/
          sudo systemctl stop my-project-${{ env.CURRENT_COLOR }}
          sudo systemctl start my-project-${{ env.NEW_COLOR }}

    - name: Wait for new application to start
      run: sleep 5

    - name: Update load balancer with new application
      uses: aws-actions/configure-aws-cli@v2
      with:
        aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
        aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
        aws-region: ${{ secrets.AWS_REGION }}
      env:
        ELB_NAME: my-project-load-balancer
      run: |
        aws elbv2 describe-target-groups --names my-project-target-group-${{ env.CURRENT_COLOR }} --query "TargetGroups[0].TargetGroupArn" > current_target_group_arn.txt
        aws elbv2 describe-target-groups --names my-project-target-group-${{ env.NEW_COLOR }} --query "TargetGroups[0].TargetGroupArn" > new_target_group_arn.txt
        aws elbv2 modify-listener --listener-arn ${{ secrets.ELB_LISTENER_ARN }} --default-actions "Type=forward,TargetGroupArn=`cat new_target_group_arn.txt`"
        aws elbv2 wait target-in-service --target-group-arn `cat new_target_group_arn.txt` --targets Id=`aws ec2 describe-instances --filters "Name=tag:Name,Values=my-project-${{ env.NEW_COLOR }}-instance" --query "Reservations[].Instances[].InstanceId" --output text`

    - name: SSH into EC2 instance and stop old application
      uses: appleboy/ssh-action@master
      with:
        host: ${{ secrets.EC2_HOST }}
        username: ${{ secrets.EC2_USER }}
        key: ${{ secrets.EC2_KEY }}
        port: ${{ secrets.EC2_PORT }}
        script: |
          cd /home/ec2-user/
          sudo systemctl stop my-project-${{ env.CURRENT_COLOR }}

    - name: Delete old JAR file
      uses: appleboy/ssh-action@master
      with:
        host: ${{ secrets.EC2_HOST }}
        username: ${{ secrets.EC2_USER }}
        key: ${{ secrets.EC2_KEY }}
        port: ${{ secrets.EC2_PORT }}
        script: |
          cd /home/ec2-user/
          rm my-project-${{ env.CURRENT_COLOR }}.jar

    - name: Update environment variables
      run: |
        echo "CURRENT_COLOR=${{ env.NEW_COLOR }}" >> $GITHUB_ENV
        echo "NEW_COLOR=$(if [[ ${{ env.NEW_COLOR }} == "blue" ]]; then echo "green"; else echo "blue"; fi)" >> $GITHUB_ENV

    - name: Cleanup
      run: |
        rm current_target_group_arn.txt new_target_group_arn.txt