CentOS Linux安装Jenkins流程以及问题

背景

        为了提高项目构建效率，决定在打包机上安装 Jenkins管理构建流程。遇到一些问题，做此纪录以防备忘。

安装

•  参考官网流程，官方教程
• 本次安装的是LTS版本

  
  #1.下载 jenkins仓库
  sudo wget -O /etc/yum.repos.d/jenkins.repo \
      https://pkg.jenkins.io/redhat-stable/jenkins.repo
  sudo rpm --import https://pkg.jenkins.io/redhat-stable/jenkins.io.key
  
  
  sudo yum upgrade
  # Add required dependencies for the jenkins package
  # 依赖于JDK11
  sudo yum install java-11-openjdk
  
  sudo yum install jenkins
  sudo systemctl daemon-reload

遇到的问题

1. 问题：安全验证已过期 Issued certificate has expired
   解决：按提示使用--no-check-certificate

   [admin@localhost ~]$sudo wget -O /etc/yum.repos.d/jenkins.repo     https://pkg.jenkins.io/redhat/jenkins.repo
   --2022-12-03 08:06:10--  https://pkg.jenkins.io/redhat/jenkins.repo
   Resolving pkg.jenkins.io (pkg.jenkins.io)... 151.101.2.133, 151.101.66.133, 151.101.130.133, ...
   Connecting to pkg.jenkins.io (pkg.jenkins.io)|151.101.2.133|:443... connected.
   ERROR: cannot verify pkg.jenkins.io's certificate, issued by ‘/C=US/O=Let's Encrypt/CN=R3’:
     Issued certificate has expired.
   To connect to pkg.jenkins.io insecurely, use `--no-check-certificate'.

2. 问题：Jenkins启动时无权限访问目录。
   原因：可以通过ps -ef | grep jenkins。默认是以jenkins用户与jenkins组运行。使用root权限 运行jenkins即可。
   解决：
   • 修改jenkins配置文件 vi /etc/sysconfig/jenkins，将JENKINS_USER改为root

     
     ## Type:        string
     ## Default:     "jenkins"
     ## ServiceRestart: jenkins
     #
     # Unix user account that runs the Jenkins daemon
     # Be careful when you change this, as you need to update
     # permissions of $JENKINS_HOME and /var/log/jenkins,
     # and if you have already run Jenkins, potentially other
     # directories such as /var/cache/jenkins .
     #
     JENKINS_USER="root"

   1. 由于是使用systemctl start jenkins进行启动服务，所有启动文件也需要修改为root用户。通过服务状态查到/usr/lib/systemd/system/jenkins.service

      [admin@localhost ~]$sudo systemctl status jenkins
      ● jenkins.service - Jenkins Continuous Integration Server
         Loaded: loaded (/usr/lib/systemd/system/jenkins.service; disabled; vendor preset: disabled)
         Active: active (running) since Fri 2022-12-02 09:44:10 CST; 22h ago
       Main PID: 32724 (java)
          Tasks: 57
         Memory: 4.0G
         CGroup: /system.slice/jenkins.service
                 └─32724 /usr/lib/jvm/java-11-openjdk-11.0.17.0.8-2.el7_9.x86_64/bin/java -Djava.awt.headless=true -jar /usr/share/java/jenkins.war --webroot=%C/jenkins/war --httpPort=1...
      

   2. 修改服务启动为root用户权限

      # Unix account that runs the Jenkins daemon
      # Be careful when you change this, as you need to update the permissions of
      # $JENKINS_HOME, $JENKINS_LOG, and (if you have already run Jenkins)
      # $JENKINS_WEBROOT.
      User=root
      Group=root

   3. 同时需要修改jenkins运行时依赖的文件

      sudo chown -R root:root /var/log/jenkins/
      sudo chown -R root:root /var/lib/jenkins/
      sudo chown -R root:root /var/cache/jenkins/

3. 问题：Invalid JDK Version，JDK版本不对，最新版本jenkins支持JDK 11起，系统旧的版本不支持。
   解决：jenkins配置文件/etc/init.d/jenkins添加JDK版本，修改启动环境变量/usr/lib/systemd/system/jenkins.service

   #1.修改  /etc/init.d/jenkins. 在candidates字段加中JDK11的安装路径
   
   # Search usable Java as /usr/bin/java might not point to minimal version required by Jenkins.
   # see http://www.nabble.com/guinea-pigs-wanted-----Hudson-RPM-for-RedHat-Linux-td25673707.html
   candidates="
   /usr/lib/jvm/java-11-openjdk-11.0.17.0.8-2.el7_9.x86_64/bin/java
   /etc/alternatives/java
   /usr/lib/jvm/java-1.8.0/bin/java
   /usr/lib/jvm/jre-1.8.0/bin/java
   /usr/lib/jvm/java-11.0/bin/java
   /usr/lib/jvm/jre-11.0/bin/java
   /usr/lib/jvm/java-11-openjdk-amd64
   /usr/bin/java
   "
   
   #2.配置启动service文件/usr/lib/systemd/system/jenkins.service，修改环境变量以JDK11启动
   
   
   # The Java home directory. When left empty, JENKINS_JAVA_CMD and PATH are consulted.
   Environment="JAVA_HOME=/usr/lib/jvm/java-11-openjdk-11.0.17.0.8-2.el7_9.x86_64"
   
   # The Java executable. When left empty, JAVA_HOME and PATH are consulted.
   Environment="JENKINS_JAVA_CMD=/usr/lib/jvm/java-11-openjdk-11.0.17.0.8-2.el7_9.x86_64/bin/java"