如何将Jenkins基础环境迁移到Docker？

Docker部署Jenkins

前往DockerHub下载Jenkins长期支持版本镜像。

查看官方的镜像历史(获取Jenkins相关信息)

ARG http_port=8080
ARG agent_port=50000
ARG JENKINS_HOME=/var/jenkins_home
ARG REF=/usr/share/jenkins/ref
ENV JENKINS_HOME=/var/jenkins_home
ENV JENKINS_SLAVE_AGENT_PORT=50000

启动Jenkins

docker run --name jenkins -itd \
       -p 8081:8080 \
       -p 50000:50000 \
       -v ~/jenkins:/var/jenkins_home \
       jenkins/jenkins:lts
docker logs -f jenkins  #查看日志并获取初始化密码

安装向导 

我想很多同学遇到过插件下载导致Jenkins安装失败的情况，为了解决这个问题我们可以通过配置插件源解决。

编辑 hudson.model.UpdateCenter.xml，这个文件是用于设置插件的更新源地址。只需要替换其中的URL。

<?xml version='1.1' encoding='UTF-8'?>
<sites>
  <site>
    <id>default</id>
    <url>https://updates.jenkins-zh.cn/update-center.json</url>
  </site>
</sites>

默认的Jenkins证书是国外官方源证书，这里切换了新的源所以需要添加新的证书。接下来更改证书。从github中获取证书文件，保存到${JENKINS_HOME}/war/WEB-INF/update-center-rootCAs/ 目录中。注意文件命名要一致。

https://github.com/jenkins-zh/docker-zh/blob/master/mirror-adapter.crt

ZeyangdeMacBook-Pro:jenkins zeyang$ cd war/WEB-INF/update-center-rootCAs/
ZeyangdeMacBook-Pro:update-center-rootCAs zeyang$ ls
jenkins-update-center-root-ca    jenkins-update-center-root-ca-2.txt
jenkins-update-center-root-ca-2    jenkins-update-center-root-ca.txt
ZeyangdeMacBook-Pro:update-center-rootCAs zeyang$ rm -fr *
ZeyangdeMacBook-Pro:update-center-rootCAs zeyang$ vim mirror-adapter.crt
ZeyangdeMacBook-Pro:update-center-rootCAs zeyang$ ls
mirror-adapter.crt
chmod 777 jenkins/

使用Docker命令重启Jenkins，重新配置安装向导。你会发现Jenkins插件安装的很快。

docker restart jenkins

创建一个admin用户

静态环境(基于Docker静态slave配置)

首先我们在Jenkins的节点管理中，添加节点。输入节点的名称和类型。

配置节点信息：自定义目录 启动方式：java web 。

获取JNLP方式运行slave所需要的秘钥信息。

java -jar agent.jar \
     -jnlpUrl http://127.0.0.1:8081/computer/build01/slave-agent.jnlp \
     -secret dcc50b0650c1deb806f1e9b855527b83c57df1fd6363ca6e2f814b0b1d273c54 \
     -workDir "/home/jenkins"

获取jnlp slave的docker镜像 https://hub.docker.com/r/jenkins/jnlp-slave

docker pull jenkins/jnlp-slave:alpine

启动slave测试，出现以下日志表示成功连接。这个部分容易出现问题，原因很可能是因为网络权限导致的。

ZeyangdeMacBook-Pro:jenkins zeyang$ docker run -it jenkins/jnlp-slave:alpine -url http://192.168.1.101:8081 dcc50b0650c1deb806f1e9b855527b83c57df1fd6363ca6e2f814b0b1d273c54 build01
Mar 03, 2020 5:20:01 AM hudson.remoting.jnlp.Main createEngine
INFO: Setting up agent: build01
Mar 03, 2020 5:20:01 AM hudson.remoting.jnlp.Main$CuiListener <init>
INFO: Jenkins agent is running in headless mode.
Mar 03, 2020 5:20:01 AM hudson.remoting.Engine startEngine
INFO: Using Remoting version: 4.0.1
Mar 03, 2020 5:20:01 AM hudson.remoting.Engine startEngine
WARNING: No Working Directory. Using the legacy JAR Cache location: /home/jenkins/.jenkins/cache/jars
Mar 03, 2020 5:20:01 AM hudson.remoting.jnlp.Main$CuiListener status
INFO: Locating server among [http://192.168.1.101:8081]
Mar 03, 2020 5:20:01 AM org.jenkinsci.remoting.engine.JnlpAgentEndpointResolver resolve
INFO: Remoting server accepts the following protocols: [JNLP4-connect, Ping]
Mar 03, 2020 5:20:01 AM hudson.remoting.jnlp.Main$CuiListener status
INFO: Agent discovery successful
  Agent address: 192.168.1.101
  Agent port:    50000
  Identity:      12:76:ae:50:52:fa:50:f9:b4:f0:29:be:72:09:eb:68
Mar 03, 2020 5:20:01 AM hudson.remoting.jnlp.Main$CuiListener status
INFO: Handshaking
Mar 03, 2020 5:20:01 AM hudson.remoting.jnlp.Main$CuiListener status
INFO: Connecting to 192.168.1.101:50000
Mar 03, 2020 5:20:01 AM hudson.remoting.jnlp.Main$CuiListener status
INFO: Trying protocol: JNLP4-connect
Mar 03, 2020 5:20:02 AM hudson.remoting.jnlp.Main$CuiListener status
INFO: Remote identity confirmed: 12:76:ae:50:52:fa:50:f9:b4:f0:29:be:72:09:eb:68
Mar 03, 2020 5:20:04 AM hudson.remoting.jnlp.Main$CuiListener status
INFO: Connected

查看效果

动态构建环境(基于Docker配置动态Slave)

docker插件：https://plugins.jenkins.io/docker-plugin/

项目地址：https://github.com/jenkinsci/docker-plugin

对与Jenkins动态slave的配置，其实就是Jenkins调用Docker的接口完成的。我们需要开启Docker远程访问。我的机器是Mac遇到很多坑，顺便学习下Mac下docker的不同配置方式。哈哈~

docker 开启API远程访问 (mac) 参考文档：https://juejin.im/entry/5bdf04b06fb9a049e41223f1

docker pull bobrik/socat
docker run -d -v /var/run/docker.sock:/var/run/docker.sock -p 2376:2375 bobrik/socat TCP4-LISTEN:2375,fork,reuseaddr UNIX-CONNECT:/var/run/docker.sock

如果你的docker环境是使用的centos系统，可以做如下配置。

编辑/usr/lib/systemd/system/docker.service

[Service]
Type=notify
# the default is not to use systemd for cgroups because the delegate issues still
# exists and systemd currently does not support the cgroup feature set required
# for containers run by docker
ExecStart=/usr/bin/dockerd -H tcp://0.0.0.0:2375 -H unix://var/run/docker.sock

systemctl daemon-reload
systemctl restart docker

当我们把上面的配置完成后，可以通过Curl命令进行基本的测试API。出现一下信息表示成功开启。

我们需要安装插件 Docker plugin

方式1：启动镜像进行构建(无需连接master)

dockerNode(dockerHost: 'tcp://192.168.43.30:2376', image: 'jenkins/jnlp-slave:alpine') {
    // some block
    sh "sleep 50"
}

方式2：使用CLoud

配置云：系统设置 -> CLoud-> Docker

Docker Cloud details

Docker Host URI Docker主机信息(需要开启Docker配置)

• tcp://192.168.1.101:2376
• unix:///var/run/docker.sock

Connection Timeout 连接超时时间

Read Timeout 读操作超时时间 (调大些，容易出现超时的情况)

Enabled 是否启用?默认否

Error Duration 错误的持续时间 默认300 5分钟

Container Cap 容器数量 负值或零，或2147483647都意味着“无限制” ,默认值100。

Docker Agent templates

• Labels 节点标签
• Enabled 是否启动 默认否
• Name 节点名称
• Docker Image 镜像标签
• Remote File System Root 远程文件系统根目录
• 用法 自定义指定项目运行
• Connect method 连接方式
• User 运行用户
• Jenkins URL jenkins地址
• Idle timeout 空闲时间多少秒后杀死slave
• JNLP 推荐
• SSH
• Docker Container
• Pull strategy 镜像下载策略
• Pull timeout 镜像下载超时时间 单位秒
• Instance Capacity 实例数量 

FAQ

Read timed out需要调整Docker Cloud details -> Read Timeout 时间。

2020-03-03 11:20:26.925+0000 [id=1253]  SEVERE  c.n.j.p.docker.DockerCloud$1#run: Error in provisioning; template='DockerTemplate{configVersion=2, labelString='jenkins-agent', connector=io.jenkins.docker.connector.DockerComputerJNLPConnector@1216d52a, remoteFs='/home/jenkins', instanceCap=2147483647, mode=NORMAL, retentionStrategy=com.nirima.jenkins.plugins.docker.strategy.DockerOnceRetentionStrategy@2677ee78, dockerTemplateBase=DockerTemplateBase{image='jenkins/jnlp-slave:alpine', pullCredentialsId='', registry=null, dockerCommand='', hostname='', dnsHosts=[], network='', volumes=[], volumesFrom2=[], environment=[], bindPorts='', bindAllPorts=false, memoryLimit=null, memorySwap=null, cpuShares=null, shmSize=null, privileged=false, tty=false, macAddress='null', extraHosts=[], extraDockerLabels=null}, removeVolumes=false, pullStrategy=PULL_NEVER, nodeProperties=[], disabled=BySystem,3.5 sec,4 min 53 sec,Template provisioning failed.}' for cloud='docker'
java.net.SocketTimeoutException: Read timed out: No data received within 10000ms.  Perhaps the docker API (tcp://192.168.1.101:2376) is not responding normally, or perhaps you need to increase the readTimeout value.

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