一，环境准备
系统：centos7
网络：服务器可以连接到公网
软件：jenkins基于JDK环境运行
yum：centos7自带的公网仓库
1.1安装JDK
这是使用yum一键安装,最新版本的使用1.8的Jdk启动的时候会报错，所以需要安装11版本的jdk，如果系统本身有别的版本的JDK，不需要删除，后面会讲到如何使用11版本的JDK来启动jenkins
查看可以安装的jdk版本
yum search jdk已加载插件：fastestmirror
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* base: mirrors.aliyun.com
* extras: mirrors.bfsu.edu.cn
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========================================================================== N/S matched: jdk ===========================================================================
copy-jdk-configs.noarch : JDKs configuration files copier
java-1.6.0-openjdk.x86_64 : OpenJDK Runtime Environment
java-1.6.0-openjdk-demo.x86_64 : OpenJDK Demos
java-1.6.0-openjdk-devel.x86_64 : OpenJDK Development Environment
java-1.6.0-openjdk-javadoc.x86_64 : OpenJDK API Documentation
java-1.6.0-openjdk-src.x86_64 : OpenJDK Source Bundle
java-1.7.0-openjdk.x86_64 : OpenJDK Runtime Environment
java-1.7.0-openjdk-accessibility.x86_64 : OpenJDK accessibility connector
java-1.7.0-openjdk-demo.x86_64 : OpenJDK Demos
java-1.7.0-openjdk-devel.x86_64 : OpenJDK Development Environment
java-1.7.0-openjdk-headless.x86_64 : The OpenJDK runtime environment without audio and video support
java-1.7.0-openjdk-javadoc.noarch : OpenJDK API Documentation
java-1.7.0-openjdk-src.x86_64 : OpenJDK Source Bundle
java-1.8.0-openjdk.i686 : OpenJDK Runtime Environment 8
java-1.8.0-openjdk.x86_64 : OpenJDK 8 Runtime Environment
java-1.8.0-openjdk-accessibility.i686 : OpenJDK accessibility connector
java-1.8.0-openjdk-accessibility.x86_64 : OpenJDK accessibility connector
java-1.8.0-openjdk-demo.i686 : OpenJDK Demos 8
java-1.8.0-openjdk-demo.x86_64 : OpenJDK 8 Demos
java-1.8.0-openjdk-devel.i686 : OpenJDK Development Environment 8
java-1.8.0-openjdk-devel.x86_64 : OpenJDK 8 Development Environment
java-1.8.0-openjdk-headless.i686 : OpenJDK Headless Runtime Environment 8
java-1.8.0-openjdk-headless.x86_64 : OpenJDK 8 Headless Runtime Environment
java-1.8.0-openjdk-javadoc.noarch : OpenJDK 8 API documentation
java-1.8.0-openjdk-javadoc-zip.noarch : OpenJDK 8 API documentation compressed in a single archive
java-1.8.0-openjdk-src.i686 : OpenJDK Source Bundle 8
java-1.8.0-openjdk-src.x86_64 : OpenJDK 8 Source Bundle
java-11-openjdk.i686 : OpenJDK Runtime Environment 11
java-11-openjdk.x86_64 : OpenJDK 11 Runtime Environment
java-11-openjdk-demo.i686 : OpenJDK Demos 11
java-11-openjdk-demo.x86_64 : OpenJDK 11 Demos
java-11-openjdk-devel.i686 : OpenJDK Development Environment 11
java-11-openjdk-devel.x86_64 : OpenJDK 11 Development Environment
java-11-openjdk-headless.i686 : OpenJDK Headless Runtime Environment 11
java-11-openjdk-headless.x86_64 : OpenJDK 11 Headless Runtime Environment
java-11-openjdk-javadoc.i686 : OpenJDK 11 API documentation
java-11-openjdk-javadoc.x86_64 : OpenJDK 11 API documentation
java-11-openjdk-javadoc-zip.i686 : OpenJDK 11 API documentation compressed in a single archive
java-11-openjdk-javadoc-zip.x86_64 : OpenJDK 11 API documentation compressed in a single archive
java-11-openjdk-jmods.i686 : JMods for OpenJDK 11
java-11-openjdk-jmods.x86_64 : JMods for OpenJDK 11
java-11-openjdk-src.i686 : OpenJDK Source Bundle 11
java-11-openjdk-src.x86_64 : OpenJDK 11 Source Bundle
java-11-openjdk-static-libs.i686 : OpenJDK libraries for static linking 11
java-11-openjdk-static-libs.x86_64 : OpenJDK 11 libraries for static linking
ldapjdk-javadoc.noarch : Javadoc for ldapjdk
icedtea-web.x86_64 : Additional Java components for OpenJDK - Java browser plug-in and Web Start implementation
ldapjdk.noarch : The Mozilla LDAP Java SDK
安装11版本的JDK
yum install -y java-11-openjdk.x86_64查看java版本
java -versionyum安装的JDK默认目录
ll /usr/lib/jvm/java-11-openjdk-11.0.15.0.9-2.el7_9.x86_64/1.2 防火墙开启jenkins的访问端口，或者关闭防火墙二选一
1.2.1 开启8888端口并生效
firewall-cmd --zone=public --add-port=8888/tcp --permanent
firewall-cmd --reload1.2.2 关闭防火墙
systemctl stop firewalld查看防火墙状态
systemctl status firewalld二，安装
首先拉取jenkins的yum文件
wget -O /etc/yum.repos.d/jenkins.repo https://pkg.jenkins.io/redhat/jenkins.repo拉取jenkins.repo的时候报错提示颁发的证书已经过去，根据提示加上--no-check-certificate 使用不安全的方式拉取
wget -O /etc/yum.repos.d/jenkins.repo https://pkg.jenkins.io/redhat/jenkins.repo --no-check-certificate安装jenkins密钥
rpm --import https://pkg.jenkins.io/redhat/jenkins.io.key使用yum一键安装Jenkins
yum -y install jenkins三，配置
配置登录jenkins的用户和连接使用的端口号
vim /usr/lib/systemd/system/jenkins.service修改以下几项
Environment="JENKINS_PORT=8888" #jenkins的启动端口
User=root 管理jenkins的用户
Group=root #管理Jenkins的组如果系统默认是别的版本的JDK的话，则需要再修改一下启动jenkins的JDK目录，这一行默认是注释的，需要把前面的#号去掉
Environment="JAVA_HOME=/usr/lib/jvm/jre-11-openjdk-11.0.15.0.9-2.el7_9.x86_64/" #JDK的目录四，启动
systemctl start jenkins查看状态,并且可以看到登录所需要的密钥
systemctl status jenkins使用可以连接到服务器IP地址的电脑，在web页面里面访问jenkins服务