一、概述
Jenkins 的前身是 Hudson 是一个可扩展的持续集成引擎。Jenkins 是一款开源 CI&CD 软件，用于自动化各种任务，包括构建、测试和部署软件。Jenkins 支持各种运行方式，可通过系统包、Docker 或者通过一个独立的 Java 程序。
二、Jenkins安装前环境准备
1、操作系统CentOS7.X，并进行Java环境的安装，建议安装1.8版本以及更高版本。如果系统没有自带git，同时安装Git。
1）安装Java1.8版本，下载地址：http://www.oracle.com/technetwork/java/javase/downloads/index.html 可以先下载好后，上传至Linux服务器。
[root@localhost data]# ls
jdk-8u181-linux-x64.tar.gz
[root@localhost data]# tar -zxvf jdk-8u181-linux-x64.tar.gz
[root@localhost data]# ls
jdk1.8.0_181 jdk-8u181-linux-x64.tar.gz
[root@localhost data]# vim /etc/profile
....................................
export JAVA_HOME=/data/jdk1.8.0_181/
export CLASSPATH=.:${JAVA_HOME}/jre/lib/rt.jar:${JAVA_HOME}/lib/dt.jar:${JAVA_HOME}/lib/tools.jar
export PATH=$PATH:${JAVA_HOME}/bin
....................................
[root@localhost data]# source /etc/profile //使环境变量生效。
[root@localhost data]# java -version
java version "1.8.0_181"
Java(TM) SE Runtime Environment (build 1.8.0_181-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.181-b13, mixed mode)
2)安装Git插件
[root@localhost data]# yum install git
已加载插件：fastestmirror, langpacks
Determining fastest mirrors
* base: mirrors.aliyun.com
* extras: mirrors.aliyun.com
* updates: mirrors.aliyun.com
base | 3.6 kB 00:00
extras | 2.9 kB 00:00
updates | 2.9 kB 00:00
(1/2): extras/7/x86_64/primary_db | 165 kB 00:00
(2/2): updates/7/x86_64/primary_db | 7.6 MB 00:01
正在解决依赖关系
--> 正在检查事务
---> 软件包 git.x86_64.0.1.8.3.1-20.el7 将被 升级
--> 正在处理依赖关系 git = 1.8.3.1-20.el7，它被软件包 perl-Git-1.8.3.1-20.el7.noarch 需要
---> 软件包 git.x86_64.0.1.8.3.1-21.el7_7 将被 更新
--> 正在检查事务
---> 软件包 perl-Git.noarch.0.1.8.3.1-20.el7 将被 升级
---> 软件包 perl-Git.noarch.0.1.8.3.1-21.el7_7 将被 更新
--> 解决依赖关系完成依赖关系解决================================================================================
三、Jenkins安装
1、第一种安装方法
[root@localhost data]# wget -O /etc/yum.repos.d/jenkins.repo https://pkg.jenkins.io/redhat-stable/jenkins.repo
--2020-04-21 09:01:53-- https://pkg.jenkins.io/redhat-stable/jenkins.repo
正在解析主机 pkg.jenkins.io (pkg.jenkins.io)... 52.202.51.185
正在连接 pkg.jenkins.io (pkg.jenkins.io)|52.202.51.185|:443... 已连接。
已发出 HTTP 请求，正在等待回应... 200 OK
长度：85
正在保存至: “/etc/yum.repos.d/jenkins.repo”100%[=========================================================================>] 85 --.-K/s 用时 0s2020-04-21 09:01:54 (19.3 MB/s) - 已保存 “/etc/yum.repos.d/jenkins.repo” [85/85])[root@localhost data]# rpm --import https://pkg.jenkins.io/redhat-stable/jenkins.io.key
[root@localhost data]# yum install jenkins
已加载插件：fastestmirror, langpacks
Loading mirror speeds from cached hostfile
* base: mirrors.aliyun.com
* extras: mirrors.aliyun.com
* updates: mirrors.aliyun.com
jenkins | 2.9 kB 00:00:00
jenkins/primary_db | 32 kB 00:00:01
正在解决依赖关系
--> 正在检查事务
---> 软件包 jenkins.noarch.0.2.222.1-1.1 将被 安装
--> 解决依赖关系完成依赖关系解决===================================================================================================================
Package 架构 版本 源 大小
===================================================================================================================
正在安装:
jenkins noarch 2.222.1-1.1 jenkins 63 M事务概要
===================================================================================================================
安装 1 软件包总下载量：63 M
安装大小：63 M
Is this ok [y/d/N]: y
Downloading packages:
^Cnkins-2.222.1-1.1.noarch.rpm 7% [== ] 21 kB/s | 4.7 MB 00:48:13 ETA
2、第二种安装方法。在Jenkins网站将稳定版本的RPM包下载后，上传至Linux服务器。
[root@localhost data]# rpm -ivh jenkins-2.222.1-1.1.noarch.rpm
准备中... ################################# [100%]
正在升级/安装...
1:jenkins-2.222.1-1.1 ################################# [100%]
1)注意：上述两种方法安装Jenkins后，需要配置环境变量，否则在启动时会出现报错。
[root@localhost data]# vim /etc/sysconfig/jenkins
...................
JENKINS_PORT="8080" //修改监听端口8080JENKINS_USER="root" //为了不因为权限出现各种问题，这里面直接修改Jenkins为root权限 并修改文件权限。
....................
[root@localhost data]# chown -R root:root /var/lib/jenkins/
[root@localhost data]# chown -R root:root /var/cache/jenkins/
[root@localhost data]# chown -R root:root /var/log/jenkins/
2)现在启动Jenkins会出现报错信息：
[root@localhost data]# service jenkins restart
Restarting jenkins (via systemctl): Job for jenkins.service failed because the control process exited with error code. See "systemctl status jenkins.service" and "journalctl -xe" for details.
[FAILED]
pathmunge /usr/sbin after[root@localhost data]# systemctl status jenkins.service
● jenkins.service - LSB: Jenkins Automation Server
Loaded: loaded (/etc/rc.d/init.d/jenkins; bad; vendor preset: disabled)
Active: failed (Result: exit-code) since 二 2020-04-21 09:13:09 CST; 10s ago
Docs: man:systemd-sysv-generator(8)
Process: 3096 ExecStart=/etc/rc.d/init.d/jenkins start (code=exited, status=1/FAILURE)4月 21 09:13:09 localhost.localdomain systemd[1]: Starting LSB: Jenkins Automation Server...
4月 21 09:13:09 localhost.localdomain runuser[3101]: pam_unix(runuser:session): session opened for user roo...d=0)
4月 21 09:13:09 localhost.localdomain jenkins[3096]: Starting Jenkins bash: /usr/bin/java: No such file or ...tory
4月 21 09:13:09 localhost.localdomain runuser[3101]: pam_unix(runuser:session): session closed for user root
4月 21 09:13:09 localhost.localdomain jenkins[3096]: [FAILED]
4月 21 09:13:09 localhost.localdomain systemd[1]: jenkins.service: control process exited, code=exited status=1
4月 21 09:13:09 localhost.localdomain systemd[1]: Failed to start LSB: Jenkins Automation Server.
4月 21 09:13:09 localhost.localdomain systemd[1]: Unit jenkins.service entered failed state.
4月 21 09:13:09 localhost.localdomain systemd[1]: jenkins.service failed.
test -e "$JENKINS_CONFIG" || { echo "$JENKINS_CONFIG not existing";
Hint: Some lines were ellipsized, use -l to show in full.
3)问题主要原因是Starting Jenkins bash: /usr/bin/java: No such file or …tory，Java环境变量。
[root@localhost data]# which java
/data/jdk1.8.0_181/bin/java
[root@localhost data]# vim /etc/init.d/jenkins
.................................
candidates="
/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-1.7.0/bin/java
/usr/lib/jvm/jre-1.7.0/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
/data/jdk2.8.0_181/bin/java //将Java路径添加此处
".....................................
[root@localhost data]# source /etc/profile
[root@localhost data]# source /etc/profile
[root@localhost data]# systemctl restart jenkins.service
Warning: jenkins.service changed on disk. Run 'systemctl daemon-reload' to reload units.
[root@localhost data]# systemctl status jenkins.service
● jenkins.service - LSB: Jenkins Automation Server
Loaded: loaded (/etc/rc.d/init.d/jenkins; bad; vendor preset: disabled)
Active: active (running) since 二 2020-04-21 09:19:33 CST; 4s ago
Docs: man:systemd-sysv-generator(8)
Process: 3479 ExecStart=/etc/rc.d/init.d/jenkins start (code=exited, status=0/SUCCESS)
CGroup: /system.slice/jenkins.service
└─3503 /data/jdk1.8.0_181/bin/java -Dcom.sun.akuma.Daemon=daemonized -Djava.awt.headless=true -DJENKI...4月 21 09:19:32 localhost.localdomain systemd[1]: Starting LSB: Jenkins Automation Server...
4月 21 09:19:33 localhost.localdomain runuser[3484]: pam_unix(runuser:session): session opened for user roo...d=0)
4月 21 09:19:33 localhost.localdomain runuser[3484]: pam_unix(runuser:session): session closed for user root
4月 21 09:19:33 localhost.localdomain jenkins[3479]: Starting Jenkins [ OK ]
4月 21 09:19:33 localhost.localdomain systemd[1]: Started LSB: Jenkins Automation Server.
Warning: jenkins.service changed on disk. Run 'systemctl daemon-reload' to reload units.
Hint: Some lines were ellipsized, use -l to show in full.
4)安装完成后，设置开机自动启动，需要知悉Jenkins相关默认路径
[root@localhost ~]# ll /usr/lib/jenkins/ //Jenkins war包
总用量 64736
-rw-r--r-- 1 root root 66288019 3月 25 22:13 jenkins.war
[root@localhost ~]# vim /etc/sysconfig/jenkins //配置文件：端口、权限 Jenkins HOME路径等
[root@localhost ~]# ls /var/lib/jenkins/ //Jenkins HOME路径
com.cloudbees.hudson.plugins.folder.config.AbstractFolderConfiguration.xml logs
config.xml nodeMonitors.xml
hudson.model.UpdateCenter.xml nodes
hudson.plugins.git.GitTool.xml plugins
identity.key.enc queue.xml.bak
jenkins.install.InstallUtil.lastExecVersion secret.key
jenkins.install.UpgradeWizard.state secret.key.not-so-secret
jenkins.model.JenkinsLocationConfiguration.xml secrets
jenkins.security.apitoken.ApiTokenPropertyConfiguration.xml updates
jenkins.security.QueueItemAuthenticatorConfiguration.xml userContent
jenkins.security.UpdateSiteWarningsConfiguration.xml users
jenkins.telemetry.Correlator.xml workflow-libs
jobs
[root@localhost ~]# ll /var/log/jenkins/jenkins.log //Jenkins日志文件
-rw-r--r-- 1 root root 56355 4月 21 13:53 /var/log/jenkins/jenkins.log
3、第三种安装方法
第三种安装方法是安装Tomcat，下载Jenkins war包，放入Tomcat内进行启动加载。本次不进行安装测试了。
四、Jenkins基本配置
1、本地使用http://IP：8080 访问Jenkins，会进入初始部署，选择推荐的插件安装。
执行下述命令查看初始密码。
[root@localhost lib]# cat /var/lib/jenkins/secrets/initialAdminPassword
cedc48233e8e4a958b77f11c59c42d65
2、安装推荐插件
登录Jenkins进行更深次的学习吧。
———————————————————–书山有路勤为径，学海无涯苦作舟————————————————————-
