Setup Jenkins

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Before install jenkins, install openjdk

# download jenkins from tsinghua mirror site
wget https://mirrors.tuna.tsinghua.edu.cn/jenkins/debian-stable/jenkins_2.277.1_all.deb

# install daemon,net-tools before install jenkins
sudo apt-get install daemon
sudo apt-get install net-tools

# link openjdk to user bin
sudo ln -s /home/zelda/jdk-11/bin/java /usr/bin/java

# install jenkins
sudo dpkg -i /home/zelda/jenkins_2.277.1_all.deb

# check jenkins status
sudo systemctl status jenkins

# full clean jenkins
sudo systemctl stop jenkins
sudo apt-get remove --purge jenkins

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To unlock jenkins, copy the password in /var/lib/jenkins/secrets/initialAdminPassword

sudo more /var/lib/jenkins/secrets/initialAdminPassword

create jenkins user

user:jkuser  
pass:jkpass  

jenkins will create a service account without shell callded ‘jenkins’ user in linux system, to login it use

sudo su -s /bin/bash jenkins

set jenkins language, install ‘locale’ plugin, on dashboard:

manage jenkins->system configuration->configure system->Locale->default language  
input 'en_US', and check 'Ignore browser preference and force this language to all users' option

set user time zone, on dashboard:

people->user->configure->User Defined Time Zone->time zone
select 'Asia/Shanghai'

add github token

manage jenkins->system configuration->configure system->github
->github server
click add credentials 

select 'secret text'  

in github 'Settings->Developer settings->Personal access tokens', 
copy token to jenkins credentials secret 

click test connection to test  

Write Pipeline Script

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check out github repo to local, use HTTPS or SSH path to clone, HTTPS don’t need add ‘credentialsId’ param, when use SSH, need add ‘credentialsId’ param, check git doc to add ssh key in github.
add ssh private key in jenkins Credentials page, copy private key content in '../.ssh/id_rsa'

write a github checkout pipeline script

checkout([
    $class: 'GitSCM',
    branches: [[name: '*/master']],
    extensions: [],
    userRemoteConfigs: [[   
            //https git clone
            //url: 'https://github.com/ivanlevsky/stand-alone-complex-tomato.git'
            
            //ssh git clone
            credentialsId: 'jenkins-ssh-key', 
            url: 'git@github.com:ivanlevsky/stand-alone-complex-tomato.git'
    ]]
])

Pipeline Error

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this is a error when jenkins ssh private key content is not correct, the key should begin with --BEGIN RSA PRIVATE KEY-- and end with --END RSA PRIVATE KEY--.

relativeTargetDir will cause permission error, due to jenkins create a user in linux called ‘jenkins’ this user don’t have permissions in the relativeTargetDir targeted folder gitproject, the targeted folder’s user is ‘zelda’

[$class: 'RelativeTargetDirectory', relativeTargetDir: '../../gitproject']

this is a error when git path is error, use which git to check git path

manage jenkins->system configuration->Global Tool Configuration->Git
->Git installations->Path to Git executable
input '/usr/bin/git' or just 'git'

Set Pipeline Script In SCM

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the pipeline script Jenkinsfile can upload to github, when build a project, jenkins will download Jenkinsfile script from SCM

in jenkins project, configure->pipeline->definition->select 'Pipeline script from SCM'

add github ssh private key when add pipeline script git url in pipeline

input script file Jenkinsfile relative path int git repo

add Additional Behaviours ‘Check out to a sub-directory’, this not working now, see pipeline relativeTargetDir error

Build Project

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reset pipeline build number

item = Jenkins.instance.getItemByFullName("github java project")
//THIS WILL REMOVE ALL BUILD HISTORY
item.builds.each() { build ->
  build.delete()
}
item.updateNextBuildNumber(1)

set mvn home in jenkins global tool configuration

tools {
    // Install the Maven version configured as "M3" and add it to the path.
    // After installed maven, run 'mvn help:effective-settings' command
    // to check .m2 path and install maven plugin
    maven "M3"
}

stages {
    stage('Build') {
        steps {
            // Run Maven on a Unix agent.
            sh "mvn -v"
            // skip tests and clean files in target folder, package jar
            sh 'mvn -B -DskipTests clean package'
            // run unit test classes
            sh 'mvn test'
        }
    }
}

Mail Notifications

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set jenkins user mail add smtp server, mail user and password test mail connection