基于 Jenkins+Docker+Git 的CI流程初探

在如今的互联网时代，随着软件开发复杂度的不断提高，软件开发和发布管理也越来越重要。目前已经形成一套标准的流程，最重要的组成部分就是持续集成（Continuous Integration，CI）及持续部署、交付（CD）。在此，我们来以一个案例初步了解 CI 流程。那么什么是 CI 呢？简单来讲，CI 就是将传统的代码合并、构建、部署、测试都集成在一起，不断地执行这个过程，并对结果进行反馈。

CI 流程设计图：

工作流程：

1. 开发人员提交代码到Git版本仓库；
2. Jenkins人工/定时触发项目构建；
3. Jenkins拉取代码、代码编码、打包镜像、推送到镜像仓库；
4. Jenkins在Docker主机创建容器并发布

主机环境规划：

docker-jenkins：    10.0.0.98

docker-git-harbor：10.0.0.99

1. 部署Git代码版本仓库

 安装：

1	[root@docker-git-harbor ~] # yum install git -y

配置git用户：

1 2	[root@docker-git-harbor ~] # useradd git [root@docker-git-harbor ~] # passwd git

创建库：

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[git@docker-git-harbor ~]$  mkdir  tomcat-java-demo.git [git@docker-git-harbor ~]$  cd  tomcat-java-demo.git/ [git@docker-git-harbor tomcat-java-demo.git]$ git --bare init Initialized empty Git repository  in  /home/git/tomcat-java-demo .git/ [git@docker-git-harbor tomcat-java-demo.git]$  ls branches  config  description  HEAD  hooks  info  objects  refs [git@docker-git-harbor tomcat-java-demo.git]$

另一台docker-jenkins访问该仓库：

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[root@docker-jenkins ~] # git clone [email protected]:/home/git/tomcat-java-demo.git Cloning into  'solo' ... The authenticity of host  '10.0.0.99 (10.0.0.99)'  can't be established. ECDSA key fingerprint is SHA256:XNWQhGsAsqd84k /6OYV3xl1 +mPGjtASsxeV1YVLZVas. ECDSA key fingerprint is MD5:b4:bd:16:2b:de:e7:7c:fd:c5: dd :91:75:20:ff:3e:0a. Are you sure you want to  continue  connecting ( yes /no )?  yes Warning: Permanently added  '10.0.0.99'  (ECDSA) to the list of known hosts. [email protected]'s password: warning: You appear to have cloned an empty repository. [root@docker-jenkins ~] # ls anaconda-ks.cfg  tomcat-java-demo.git [root@docker-jenkins ~] # ls tomcat-java-demo.git [root@docker-jenkins ~] #

 模拟生产项目，拉取github上的一个demo，并上传至本地git库

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[root@docker-jenkins ~] # mv tomcat-java-demo tomcat-java-demo.bak [root@docker-jenkins ~] # git clone https://github.com/dingkai163/tomcat-java-demo.git [root@docker-jenkins tomcat-java-demo] # cat .git/config [core]      repositoryformatversion = 0      filemode =  true      bare =  false      logallrefupdates =  true [remote  "origin" ]      url = [email protected]: /home/git/tomcat-java-demo .git   # 修改为本地的git库地址      fetch = +refs /heads/ *:refs /remotes/origin/ * [branch  "master" ]      remote = origin      merge = refs /heads/master [root@docker-jenkins tomcat-java-demo] # git add . [root@docker-jenkins tomcat-java-demo] # git status # On branch master nothing to commit, working directory clean [root@docker-jenkins tomcat-java-demo] # git commit -m "all" # On branch master nothing to commit, working directory clean [root@docker-jenkins tomcat-java-demo] # git push origin master [email protected]'s password: Counting objects: 229,  done . Compressing objects: 100% (185 /185 ),  done . Writing objects: 100% (229 /229 ), 4.52 MiB | 0 bytes /s ,  done . Total 229 (delta 25), reused 229 (delta 25) To [email protected]: /home/git/tomcat-java-demo .git   * [new branch]      master -> master [root@docker-jenkins tomcat-java-demo] #

2. jenkins环境部署 

部署jdk环境及maven

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[root@docker-jenkins ~] # mkdir tools [root@docker-jenkins ~] # cd tools [root@docker-jenkins tools] # rz -y [root@docker-jenkins tools] # tar zxvf jdk-8u45-linux-x64.tar.gz [root@docker-jenkins tools] # mv jdk1.8.0_45 /usr/local/jdk [root@docker-jenkins tools] # vim /etc/profile JAVA_HOME= /usr/local/jdk  PATH=$PATH:$JAVA_HOME /bin   CLASSPATH=.:$JAVA_HOME /lib/dt .jar:$JAVA_HOME /lib/tools .jar  export  JAVA_HOME PATH CLASSPATH [root@docker-jenkins tools] # source /etc/profile [root@docker-jenkins tools] # java -version java version  "1.8.0_45" Java(TM) SE Runtime Environment (build 1.8.0_45-b14) Java HotSpot(TM) 64-Bit Server VM (build 25.45-b02, mixed mode)   [root@docker-jenkins tools] # tar zxf apache-maven-3.5.0-bin.tar.gz [root@docker-jenkins tools] # mv apache-maven-3.5.0 /usr/local/maven

在10.0.0.98主机安装Jenkins，下载Tomcat二进制包将war包到webapps下即可：

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[root@docker-jenkins tools] # wget http://mirrors.jenkins.io/war-stable/latest/jenkins.war [root@docker-jenkins tools] # wget http://mirrors.shu.edu.cn/apache/tomcat/tomcat-8/v8.5.38/bin/apache-tomcat-8.5.38.tar.gz [root@docker-jenkins tools] # tar zxf apache-tomcat-8.5.38.tar.gz [root@docker-jenkins tools] # ls apache-tomcat-8.5.38  apache-tomcat-8.5.38. tar .gz  jdk-8u45-linux-x64. tar .gz  jenkins.war [root@docker-jenkins tools] # mv apache-tomcat-8.5.38 /usr/local/tomcat-jenkins [root@docker-jenkins tools] # ls /usr/local/tomcat-jenkins/webapps/ docs  examples  host-manager  manager  ROOT [root@docker-jenkins tools] # rm -rf /usr/local/tomcat-jenkins/webapps/* [root@docker-jenkins tools] # mv jenkins.war /usr/local/tomcat-jenkins/webapps/ROOT.war [root@docker-jenkins tools] # ll /usr/local/tomcat-jenkins/webapps/ total 75520 -rw-r--r--. 1 root root 77330344 Mar 15 00:55 ROOT.war [root@docker-jenkins tools] # cd /usr/local/tomcat-jenkins/bin/ [root@docker-jenkins bin] # ./startup.sh Using CATALINA_BASE:    /usr/local/tomcat-jenkins Using CATALINA_HOME:    /usr/local/tomcat-jenkins Using CATALINA_TMPDIR:  /usr/local/tomcat-jenkins/temp Using JRE_HOME:         /usr/local/jdk1 .8 Using CLASSPATH:        /usr/local/tomcat-jenkins/bin/bootstrap .jar: /usr/local/tomcat-jenkins/bin/tomcat-juli .jar Tomcat started. [root@docker-jenkins bin] #

启动后，浏览器访问http://10.0.0.98:8080/，按提示输入密码，登录即可。

3. 部署私有镜像仓库

企业级harbor镜像仓库部署：

https://www.cnblogs.com/kaye/p/10524391.html

构建Tomcat基础镜像，并推送到harbor镜像库：

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[root@docker-git-harbor ~] # cd tomcat [root@docker-git-harbor tomcat] # cat Dockerfile-tomcat FROM centos:7 MAINTAINER www.cnblogs.com /kaye/   ENV VERSION=8.5.38   RUN yum  install  java-1.8.0-openjdk wget curl unzip iproute net-tools -y && \      yum clean all && \      rm  -rf  /var/cache/yum/ * RUN wget http: //mirrors .shu.edu.cn /apache/tomcat/tomcat-8/v ${VERSION} /bin/apachetomcat- ${VERSION}. tar .gz && \      tar  zxf apache-tomcat-${VERSION}. tar .gz && \      mv  apache-tomcat-${VERSION}  /usr/local/tomcat  && \      rm  -rf apache-tomcat-${VERSION}. tar .gz  /usr/local/tomcat/webapps/ * && \      mkdir  /usr/local/tomcat/webapps/test  && \      echo  "ok"  >  /usr/local/tomcat/webapps/test/status .html && \      sed  -i  '1a JAVA_OPTS="-Djava.security.egd=file:/dev/./urandom"'  /usr/local/tomcat/bin/catalina .sh && \      ln  -sf  /usr/share/zoneinfo/Asia/Shanghai  /etc/localtime   ENV PATH $PATH: /usr/local/tomcat/bin   EXPOSE 8080 CMD [ "catalina.sh" ,  "run" ] [root@docker-git-harbor tomcat] # docker build -t tomcat:v1 -f Dockerfile-tomcat . [root@docker-git-harbor tomcat] # docker tag tomcat:v1 reg.dingkai.com/library/tomcat:v1 [root@docker-git-harbor tomcat] # docker login reg.dingkai.com [root@docker-git-harbor tomcat] # docker push reg.dingkai.com/library/tomcat:v1

4. Jenkins安装必要插件

由于jenkins是离线安装，所有在此需要配置一下插件下载地址：系统管理-->插件管理-->Advanced

修改下方地址，将https修改为http 再点Submit

Submit后点击Available，Check now此时我们可以看到很多可获得插件

首先搜索并安装Pipeline插件
pipeline 是一套运行于jenkins上的工作流框架，将原本独立运行于单个或者多个节点的任务连接起来，实现单个任务难以完成的复杂流程编排与 
可视化。

再安装SCM to job 插件，同上步骤（搜索，安装）。

 5. 项目创建

创建jobs

 

选择流水线类型

到这里我们就开始配置Pipeline script，点击Pipeline语法，来自动生成我们需要的配置。

如下图，我们Git方式，配置Git仓库地址，再添加认证相关。

这里我们使用的是秘钥认证方式，需要将jenkins上生成的公钥发送到git服务器上，然后将jenkins上的生成的私钥内容粘贴到下图Key中，这样jenkins就可以免交互的拉取git仓库中的代码了。

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[root@docker-jenkins bin] # ssh-keygen Generating public /private  rsa key pair. Enter  file  in  which  to save the key ( /root/ . ssh /id_rsa ): Enter passphrase (empty  for  no passphrase): Enter same passphrase again: Your identification has been saved  in  /root/ . ssh /id_rsa . Your public key has been saved  in  /root/ . ssh /id_rsa .pub. The key fingerprint is: SHA256:1vD8XM3lDYFmrxgAbwPTLwb0fl+oEx8cFgtykpg4ODI root@docker-jenkins The key's randomart image is: +---[RSA 2048]----+ |   . o==o.o ...  | |E o o +=++ .+o . | | o . . .*o o+.. .| |       oo*oo o.=o| |       .S.*o+.o =| |       . ..B.+   | |          o =    | |           .     | |                 | +----[SHA256]-----+ [root@docker-jenkins bin] # cd [root@docker-jenkins ~] # [root@docker-jenkins ~] # [root@docker-jenkins ~] # ls .ssh/ id_rsa  id_rsa.pub  known_hosts [root@docker-jenkins ~] # ssh-copy-id [email protected] /usr/bin/ssh-copy-id : INFO: Source of key(s) to be installed:  "/root/.ssh/id_rsa.pub" /usr/bin/ssh-copy-id : INFO: attempting to log  in  with the new key(s), to filter out any that are already installed /usr/bin/ssh-copy-id : INFO: 1 key(s) remain to be installed --  if  you are prompted now it is to  install  the new keys [email protected]'s password:   Number of key(s) added: 1   Now try logging into the machine, with:    "ssh '[email protected]'" and check to  make  sure that only the key(s) you wanted were added.   [root@docker-jenkins ~] #

 

配置完成后，我们就可以生成Pipeline脚本了。点击下方Generate Pipeline Script，然后复制方框内的内容。

编写我们所需要的Pipeline脚本如下，将其粘贴到script的拉取代码模块中，并修改分支master为${branch}，其他模块内容自行编写。

node { 
   // 拉取代码
   stage('Git Checkout') { 
       checkout([$class: 'GitSCM', branches: [[name: '${branch}']], doGenerateSubmoduleConfigurations: false, extensions: [], submoduleCfg: [], userRemoteConfigs: [[credentialsId: 'c42214eb-db1e-49fb-83c9-f78d1f4310a2', url: '[email protected]:/home/git/tomcat-java-demo.git']]])
   }
   // 代码编译
   stage('Maven Build') {
        sh '''
        export JAVA_HOME=/usr/local/jdk
        /usr/local/maven/bin/mvn clean package -Dmaven.test.skip=true
        '''
   }
   // 项目打包到镜像并推送到镜像仓库
   stage('Build and Push Image') {
sh '''
REPOSITORY=reg.dingkai.com/library/tomcat-java-demo:${branch}
cat > Dockerfile << EOF
FROM reg.dingkai.com/library/tomcat:v1 
MAINTAINER kai
RUN rm -rf /usr/local/tomcat/webapps/*
ADD target/*.war /usr/local/tomcat/webapps/ROOT.war
EOF
docker build -t $REPOSITORY .
docker login reg.dingkai.com -u admin -p 123456
docker push $REPOSITORY
'''
   }
   // 部署到Docker主机
   stage('Deploy to Docker') {
        sh '''
        REPOSITORY=reg.dingkai.com/library/tomcat-java-demo:${branch}
        docker rm -f tomcat-java-demo |true
        docker pull $REPOSITORY
        docker container run -d --name tomcat-java-demo -p 88:8080 $REPOSITORY
        '''
   }
}

在Pipeline脚本里面我们指定了一个branch参数，所以我们需要传递一个参数变量，这里我们选择参数化构建，默认值为master分支。

然后保存配置。

6. 开始构建任务

回到主界面，我们开始构建任务

可以通过Console Output输出查看jenkins构建流程

成功构建会提示： SUCCESS

我们也可以查看构建成功后的图形构建过程

通过浏览器来访问tomcat-java-demo项目：http://10.0.0.98:88/

可以看到可以正常访问，至此基于 Jenkins+Docker+Git 的CI流程已经成功部署了。