Jenkins

Continuous Integration with Jenkins

1: Jenkins
2: Jenkins-Docker

1 - Jenkins

Code Snippets

How to get list of all installed plugins

import jenkins.model.Jenkins 
Jenkins.instance.pluginManager.plugins.each{ 
  plugin ->  
    println ("${plugin.getDisplayName()} (${plugin.getShortName()}): ${plugin.getVersion()}") 
}

How to test NodeJS

node('linux') {
stage('Linux :: NodeJS :: Default' ) { 
    sh 'node --version' 
}
stage('Linux :: NodeJS :: v8.9.0' ) {
    def nodejs = tool name: 'Linux NodeJS v8.9.0', type: 'jenkins.plugins.nodejs.tools.NodeJSInstallation'
    sh "$ {nodejs}/bin/node --version"
}
stage('Linux :: NodeJS :: v8.9.0:: withEnv' ) {
    withEnv(["PATH+NODE=${tool 'Linux NodeJS v8.9.0'}/bin"]){ 
        sh 'node --version' 
        }
    }
}

Parallel Pipelines

def labels = [
    'node1',
	'node2'
    ]
def builders = [:]
for (x in labels) {
    def label = x 
    // Create a map to pass in to the 'parallel' step so we can fire all the builds at once
    builders[label] = {
      node(label) {
        // build steps that should happen on all nodes go here
        }
    }
}
parallel builders

2 - Jenkins-Docker

Docker Slave for Jenkins

My use case is to run jenkins pipelines on docker build slaves. To achieve this we have to install Docker plugin. Docker plugin will integrate Jenkins with Docker. This docker plugin depends on Docker API plugin, so intall both the plugins. Restart is required for jenkins after installing these plugins.

Manage Jenkins -> Manage Plugins -> Docker plugin , Docker slave plugin and Docker API plugin

Once docker plugins are installed, restart jenkins master.

Jenkins depends on specific version of Java, in my case i have OpenJDK 10.0.2 installed in my system and jenkins needs java 1.8, hence i downloaded JDK 1.8 and running jenkins with that version of java.

Running Jenkins from war file

export JAVA_HOME=/home/sriram/Downloads/jdk-8u191-linux-x64/jdk1.8.0_191
$JAVA_HOME/bin/java -jar jenkins.war &

Once jenkins is fully up and running , we can see .jenkins folder inside user home directory /home/sriram/.jenkins/

sriram@optimus-prime:~/.jenkins$ pwd
/home/sriram/.jenkins
sriram@optimus-prime:~/.jenkins$ ll
total 104
drwxr-xr-x 12 sriram sriram  4096 nov 10 12:56 ./
drwxr-xr-x 44 sriram sriram  4096 nov 10 12:51 ../
-rw-r--r--  1 sriram sriram  1644 nov 10 12:56 config.xml
-rw-r--r--  1 sriram sriram   156 nov 10 12:56 hudson.model.UpdateCenter.xml
-rw-r--r--  1 sriram sriram   370 nov 10 12:51 hudson.plugins.git.GitTool.xml
-rw-------  1 sriram sriram  1712 nov 10 12:49 identity.key.enc
-rw-r--r--  1 sriram sriram    94 nov 10 12:49 jenkins.CLI.xml
-rw-r--r--  1 sriram sriram     7 nov 10 12:53 jenkins.install.InstallUtil.lastExecVersion
-rw-r--r--  1 sriram sriram     7 nov 10 12:53 jenkins.install.UpgradeWizard.state
-rw-r--r--  1 sriram sriram   179 nov 10 12:53 jenkins.model.JenkinsLocationConfiguration.xml
-rw-r--r--  1 sriram sriram   171 nov 10 12:49 jenkins.telemetry.Correlator.xml
drwxr-xr-x  2 sriram sriram  4096 nov 10 12:49 jobs/
drwxr-xr-x  3 sriram sriram  4096 nov 10 12:49 logs/
-rw-r--r--  1 sriram sriram   907 nov 10 12:56 nodeMonitors.xml
drwxr-xr-x  2 sriram sriram  4096 nov 10 12:49 nodes/
drwxr-xr-x 75 sriram sriram 12288 nov 10 12:51 plugins/
-rw-r--r--  1 sriram sriram   129 nov 10 12:55 queue.xml.bak
-rw-r--r--  1 sriram sriram    64 nov 10 12:49 secret.key
-rw-r--r--  1 sriram sriram     0 nov 10 12:49 secret.key.not-so-secret
drwx------  4 sriram sriram  4096 nov 10 12:53 secrets/
drwxr-xr-x  2 sriram sriram  4096 nov 10 12:50 updates/
drwxr-xr-x  2 sriram sriram  4096 nov 10 12:49 userContent/
drwxr-xr-x  3 sriram sriram  4096 nov 10 12:53 users/
drwxr-xr-x 11 sriram sriram  4096 nov 10 12:49 war/
drwxr-xr-x  2 sriram sriram  4096 nov 10 12:51 workflow-libs/
sriram@optimus-prime:~/.jenkins$

Adding Jenkins Node (Method-1)

This approach is a static method of using docker container as a build slave.

create a node in jenkins with Launch method = Launch agent via Java Web Start
Using the node name and secret key, spin up a container.
This runing container will act as a build node for jenkins.

I have used jenkins docker slave image from cloudbees. jenkinsci/jnlp-slave

syntax:
docker run jenkins/jnlp-slave -url http://jenkins-server:port <secret> <agent name>

example:
docker run jenkins/jnlp-slave -url http://192.168.2.8:8080 8302b7d76d0828b629bdd1460d587268af64616fe464d69f34c9119f5670f1f3 docker-agent-1

Configure Docker Slaves for Jenkins (Method-2)

Go to Manage Jenkins -> Configure System -> you will now see Cloud option with a drop down to select Docker.

TO-DO

Add screenshots from Jenkins Configuration