使用Docker在Linux上实现持续集成和持续部署(CI/CD)

基础环境准备

1. 安装Docker

   # Ubuntu/Debian
   sudo apt-get update
   sudo apt-get install docker-ce docker-ce-cli containerd.io
   
   # CentOS/RHEL
   sudo yum install -y yum-utils
   sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
   sudo yum install docker-ce docker-ce-cli containerd.io
   sudo systemctl start docker && sudo systemctl enable docker
   

2. 安装Docker Compose

   sudo curl -L "https://github.com/docker/compose/releases/download/1.29.2/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
   sudo chmod +x /usr/local/bin/docker-compose
   

持续集成(CI)实现方案

方案1: 使用Jenkins

1. 安装Jenkins

   docker run -d --name jenkins -p 8080:8080 -p 50000:50000 \
   -v jenkins_home:/var/jenkins_home \
   jenkins/jenkins:lts
   

2. 配置Jenkins Pipeline

   pipeline {
      agent any
      stages {
          stage('Build') {
              steps {
                  sh 'docker build -t myapp:${BUILD_NUMBER} .'
              }
          }
          stage('Test') {
              steps {
                  sh 'docker run myapp:${BUILD_NUMBER} npm test'
              }
          }
          stage('Push') {
              steps {
                  withCredentials([usernamePassword(credentialsId: 'dockerhub', usernameVariable: 'USERNAME', passwordVariable: 'PASSWORD')]) {
                      sh 'docker login -u $USERNAME -p $PASSWORD'
                      sh 'docker tag myapp:${BUILD_NUMBER} $USERNAME/myapp:${BUILD_NUMBER}'
                      sh 'docker push $USERNAME/myapp:${BUILD_NUMBER}'
                  }
              }
          }
      }
   }
   

方案2: 使用GitLab CI

1. 配置.gitlab-ci.yml

   stages:
    - build
    - test
    - deploy
   
   build:
    stage: build
    script:
      - docker build -t $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA .
      - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
      - docker push $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
   
   test:
    stage: test
    script:
      - docker run $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA npm test
   
   deploy:
    stage: deploy
    script:
      - ssh user@server "docker pull $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA"
      - ssh user@server "docker stop myapp || true"
      - ssh user@server "docker rm myapp || true"
      - ssh user@server "docker run -d --name myapp -p 80:3000 $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA"
   

持续部署(CD)实现方案

方案1: 使用Docker Swarm

1. 初始化Swarm集群

   docker swarm init
   

2. 创建Docker Stack文件

   # docker-stack.yml
   version: '3.8'
   services:
    app:
      image: your-registry/your-app:latest
      deploy:
        replicas: 3
        update_config:
          parallelism: 1
          delay: 10s
        restart_policy:
          condition: on-failure
      ports:
        - "80:3000"
   

3. 部署应用

   docker stack deploy -c docker-stack.yml myapp
   

方案2: 使用Kubernetes

1. 安装Minikube或配置K8s集群

   # Minikube安装
   curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64
   sudo install minikube-linux-amd64 /usr/local/bin/minikube
   

2. 创建Deployment和Service ```yaml

   deployment.yaml

   apiVersion: apps/v1 kind: Deployment metadata: name: myapp spec: replicas: 3 selector: matchLabels: app: myapp template: metadata: labels: app: myapp spec: containers: - name: myapp image: your-registry/your-app:latest ports: - containerPort: 3000

apiVersion: v1 kind: Service metadata: name: myapp spec: selector: app: myapp ports: - protocol: TCP port: 80 targetPort: 3000 type: LoadBalancer ```

3. 部署应用 bash kubectl apply -f deployment.yaml

监控与日志管理

1. 使用Prometheus监控

   docker run -d --name=prometheus -p 9090:9090 \
   -v /path/to/prometheus.yml:/etc/prometheus/prometheus.yml \
   prom/prometheus
   

2. 使用Grafana可视化

   docker run -d --name=grafana -p 3000:3000 grafana/grafana
   

3. 集中日志管理(ELK)

   # Elasticsearch
   docker run -d --name elasticsearch -p 9200:9200 -p 9300:9300 -e "discovery.type=single-node" elasticsearch:7.14.0
   
   # Logstash
   docker run -d --name logstash --link elasticsearch:elasticsearch -p 5000:5000 logstash:7.14.0
   
   # Kibana
   docker run -d --name kibana --link elasticsearch:elasticsearch -p 5601:5601 kibana:7.14.0
   

最佳实践建议

1. 使用多阶段构建减少镜像大小

   FROM node:14 as builder
   WORKDIR /app
   COPY . .
   RUN npm install && npm run build
   
   FROM nginx:alpine
   COPY --from=builder /app/dist /usr/share/nginx/html
   

2. 使用.dockerignore文件忽略不必要的文件

   node_modules
   .git
   *.log
   

3. 实现蓝绿部署或金丝雀发布减少部署风险

4. 定期清理旧镜像

   docker system prune -f
   

5. 使用健康检查

   HEALTHCHECK --interval=30s --timeout=3s \
   CMD curl -f http://localhost/health || exit 1
   

通过以上方案，您可以在Linux上构建完整的Docker CI/CD流水线，实现从代码提交到生产部署的自动化流程。