Github Actions - Docker - EC2 무중단 배포하기

□ Dockerfile

# 1. Gradle을 이용해 애플리케이션 빌드
FROM gradle:8.12-jdk17 AS builder
WORKDIR /app
COPY . .
RUN gradle build --no-daemon

# 2. 실행 환경
FROM openjdk:17-slim
WORKDIR /app
ENV DB_USERNAME=${DB_USERNAME}
ENV DB_PASSWORD=${DB_PASSWORD}
ENV jwt_secret_key=${jwt_secret_key}
ENV origin_ip=${origin_ip}
ENV aes_secret_key=${aes_secret_key}
COPY --from=builder /app/build/libs/*.jar app.jar
ENTRYPOINT ["java", "-jar", "app.jar"]
EXPOSE 8080

□ docker-compose

services:
  mysql:
    image: mysql:latest
    container_name: mysql
    restart: always
    environment:
      - MYSQL_ROOT_PASSWORD=${ROOT_PASSWORD}
      - MYSQL_DATABASE=cointrading
      - MYSQL_USER=${DB_USERNAME}
      - MYSQL_PASSWORD=${DB_PASSWORD}
    ports:
      - "3306:3306"
    volumes:
      - mysql-data:/var/lib/mysql
    networks:
      - app-network
    healthcheck:
      test: ["CMD", "mysqladmin", "ping", "-h", "localhost"]
      interval: 10s
      timeout: 5s
      retries: 5

  redis:
    image: redis:latest
    command: ["redis-server"]
    container_name: redis
    ports:
      - "6379:6379"
    volumes:
      - redis-data:/data
    networks:
      - app-network
    restart: always
    healthcheck:
      test: ["CMD", "redis-cli", "ping"]
      interval: 10s
      timeout: 5s
      retries: 5

  cointrading:
    image: ${DOCKER_USERNAME}/cointrading:latest
    container_name: cointrading
    ports:
      - "8080:8080"
    environment:
      - TZ=Asia/Seoul
      - DB_HOST=mysql
      - SPRING_REDIS_HOST=redis
      - REDIS_HOST=${REDIS_HOST}
      - JWT_SECRET_KEY=${JWT_SECRET_KEY}
      - AES_SECRET_KEY=${AES_SECRET_KEY}
      - DB_URL=${DB_URL}
      - DB_USERNAME=${DB_USERNAME}
      - DB_PASSWORD=${DB_PASSWORD}
    depends_on:
      mysql:
        condition: service_healthy
      redis:
        condition: service_healthy
    networks:
      - app-network
    restart: always

volumes:
  redis-data:
  mysql-data:

networks:
  app-network:
    driver: bridge

• mysql을 예시로
• mysql: → mysql이라는 이름의 서비스를 정의
• image: mysql:latest → 해당 이미지를 사용하여 MySQL 컨테이너를 생성, latest는 최신을 의미
• container_name: → 컨테이너의 이름을 지정
• restart: always → 컨테이너가 중지되거나 실패할 경우 자동으로 다시 시작
• environment: → 컨테이너의 환경변수를 설정
• ports: → MySQL 컨테이너의 포트를 호스트 머신과 연결
• volumes: → 데이터가 호스트 머신에 저장되도록 설정
• networks: → 컨테이너가 연결될 네트워크를 설정
• healthcheck: → 컨테이너의 상태를 체크
  
  • test:["CMD", "mysqladmin", "ping", "-h", "localhost"] MySQL서버가 정상적으로 실행 중인지 확인
  • interval: → 실행간격
  • timeout: → 체크 명령의 타임아웃
  • retries: → 체크 실패가 n번 발생하면 비정상으로 간주되어 재실행

□ Github Actions - workflow

name: CI/CD with Docker & Gradle

on:
  push:
    branches: [ "main" ]
  pull_request:
    branches: [ "main" ]

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4

      - name: Set up JDK 17
        uses: actions/setup-java@v4
        with:
          java-version: '17'
          distribution: 'temurin'

      - name: Setup Gradle
        uses: gradle/actions/setup-gradle@af1da67850ed9a4cedd57bfd976089dd991e2582 # v4.0.0

      - name: Build with Gradle Wrapper
        run: ./gradlew build

      - name: Docker 로그인
        run: echo "${{ secrets.DOCKER_PASSWORD }}" | docker login -u "${{ secrets.DOCKER_USERNAME }}" --password-stdin

      - name: Docker 이미지 빌드
        run: docker build -t ${{ secrets.DOCKER_USERNAME }}/cointrading:latest .

      - name: Docker Hub에 Push
        run: docker push ${{ secrets.DOCKER_USERNAME }}/cointrading:latest

      - name: Set up SSH Key
        run: |
          echo "${{ secrets.EC2_SSH_KEY }}" > private_key.pem
          chmod 600 private_key.pem

      - name: Transfer docker-compose.yml to EC2
        run: |
          scp -i private_key.pem -o StrictHostKeyChecking=no docker-compose.yml ubuntu@${{ secrets.EC2_HOST }}:/home/ubuntu/


  deploy:
    runs-on: ubuntu-latest
    needs: build

    steps:
      - name: EC2 서버에 배포 (SSH 접속)
        uses: appleboy/ssh-action@v0.1.7
        with:
          host: ${{ secrets.EC2_HOST }}
          username: ubuntu
          key: ${{ secrets.EC2_SSH_KEY }}
          script: |
            # Docker Compose가 설치되어 있는지 확인
            if ! docker compose version &> /dev/null && ! docker-compose version &> /dev/null; then
              echo "Docker Compose could not be found, installing..."
              sudo apt-get update
              sudo apt-get install -y docker-compose-plugin
              sudo ln -s /usr/libexec/docker/cli-plugins/docker-compose /usr/local/bin/docker-compose || true
            else
              echo "Docker Compose is already installed"
            fi

            # 환경 변수 파일 생성 (.env)
            echo "REDIS_HOST=redis" > ~/.env
            echo "DB_URL=jdbc:mysql://mysql:3306/cointrading" >> ~/.env
            echo "DB_USERNAME=${{ secrets.DB_USERNAME }}" >> ~/.env
            echo "DB_PASSWORD=${{ secrets.DB_PASSWORD }}" >> ~/.env
            echo "AES_SECRET_KEY=${{ secrets.AES_SECRET_KEY }}" >> ~/.env
            echo "JWT_SECRET_KEY=${{ secrets.JWT_SECRET_KEY }}" >> ~/.env
            echo "ROOT_PASSWORD=${{ secrets.ROOT_PASSWORD }}" >> ~/.env
            echo "DOCKER_USERNAME=${{ secrets.DOCKER_USERNAME }}" >> ~/.env

            # 최신 Docker 이미지 풀
            docker stop cointrading || true
            docker rm -f cointrading || true
            docker rmi -f ${{ secrets.DOCKER_USERNAME }}/cointrading:latest || true
            docker pull ${{ secrets.DOCKER_USERNAME }}/cointrading:latest

            # Docker Compose 실행 (자동으로 .env 파일 로드)
            cd ~/cointrading
            docker-compose down
            docker-compose up -d
            
            rm -f ~/.env