参考:Installing Jenkins
参考:How to Install and Configure Jenkins on Ubuntu 20.04 LTS

一、安装前提

Java 8 or Java 11 are required for running modern versions of Jenkins. All other Java versions are not supported.

二、安装JDK

如果没安装会有提示

root@cn-office-tonytest-jenkins:/home/ubuntu# java -version
 
Command 'java' not found, but can be installed with:
apt install openjdk-11-jre-headless  # version 11.0.13+8-0ubuntu1~20.04
apt install openjdk-8-jre-headless   # version 8u312-b07-0ubuntu1~20.04

root@ali-hn-lw-jenkins-new:~# cat /var/lib/jenkins/config.xml | grep version
  2.190.2
dpkg -l | grep jenkins  

三、安装jenkins

密码:c002de146aeb4c3a9ff12eca419c7da3

四、配置jenkins使用Git

1. 在需要拉取代码的服务器生成新的密钥,或者用已有的：
ssh-keygen
生成了二个文件在.ssh/目录下:id_rsa 和 id_rsa.pub

jenkins@cn-office-tonytest-jenkins:~$ ssh-keygen
Generating public/private rsa key pair.
Your identification has been saved in /var/lib/jenkins/.ssh/id_rsa
Your public key has been saved in /var/lib/jenkins/.ssh/id_rsa.pub
jenkins@cn-office-tonytest-jenkins:~$ cat .ssh/id_rsa.pub 
ssh-rsa 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 jenkins@cn-office-tonytest-jenkins

2.拷贝公钥到你的gitlab
登录gitlab-->点击profile settings-->SSH Keys-->打开id_rsa.pub（公钥） 复制全部内容到Key这个选项
3. 验证
保证git@gitlab.51sw.cc22端口对密钥生成的服务器开放

jenkins@cn-office-tonytest-jenkins:~/test$ git clone git@gitlab.51sw.cc:bw/crm-all.git
Cloning into 'crm-all'...
Updating files: 100% (5742/5742), done.

4. 在jenkins上管理页面配置
现在是jenkins需要拉取git@gitlab.51sw.cc:bw/crm-all.git，公钥已经放在gitlab了，jenkins上管理页面配置还需要配置下刚才生成的私钥
manage jenkins-->manage credentials-->system-->global credentials-->添加credentials-->拷贝刚才生成的私钥到对应配置项

五、一些安全策略配置