Jenkins + Kubernetes CI/CD
步骤如下

1. 安装Kubernetes集群
2. 开通容器镜像服务，创建镜像仓库，如ycdocker/demo
3. 在集群外的ECS上安装Jenkins

4. 在Jenkins所在ECS安装kubectl，用以访问Kubernetes集群

   wget https://dl.k8s.io/v1.10.6/kubernetes-client-linux-amd64.tar.gz
   tar -xvf kubernetes-client-linux-amd64.tar.gz
   cd kubernetes/client/bin
   chmod +x ./kubectl
   sudo mv ./kubectl /usr/local/bin/kubectl
   mkdir /root/.kube
   vi /root/.kube/config

5. 安装Docker

   
   # step 1: 安装必要的一些系统工具
   sudo apt-get update
   sudo apt-get -y install apt-transport-https ca-certificates curl software-properties-common
   # step 2: 安装GPG证书
   curl -fsSL http://mirrors.aliyun.com/docker-ce/linux/ubuntu/gpg | sudo apt-key add -
   # Step 3: 写入软件源信息
   sudo add-apt-repository "deb [arch=amd64] http://mirrors.aliyun.com/docker-ce/linux/ubuntu $(lsb_release -cs) stable"
   # Step 4: 更新并安装 Docker-CE
   sudo apt-get -y update
   sudo apt-get -y install docker-ce

6. 安装maven apt-get install maven -y

7. 选择Spring Boot Demo项目，Dockerfile放根目录

   FROM openjdk:8-jdk-alpine
   VOLUME /tmp
   ARG JAR_FILE
   COPY ${JAR_FILE} app.jar
   ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/app.jar"]

8. 上传代码到Git
9. 登陆Jenkins，创建free style项目
10. 配置Jenkins从Git取代码
11. 添加构建步骤，Shell脚本如下

mvn clean package
docker build --build-arg JAR_FILE=target/gs-spring-boot-docker-0.1.0.jar -t registry.cn-beijing.aliyuncs.com/ycdocker/demo:$BUILD_NUMBER .
docker login --username=***** --password=***** registry.cn-beijing.aliyuncs.com
docker push registry.cn-beijing.aliyuncs.com/ycdocker/demo:$BUILD_NUMBER
kubectl set image deployment/demo demo=registry.cn-beijing.aliyuncs.com/ycdocker/demo:$BUILD_NUMBER

1. 修改代码测试效果