<h1 style='font-size:26px;color:#6aa84f;'>jenkins: install an ubuntu slave as a service. </h1>

Before we start to write any line of code, we should make sure, that out buildsystem is running and the CI process in our new project is automatted.

The CI pipline only is complete, when you deploy your project directly to your test , stage and liveservern.

One possibility is, to register your webserver as a slave on your buildserver.

In our case we are using jenkins as a master build server and a ubuntu webserver as a slave.

If everythings is correct, you will see yout slavenode on the jenkinsdashboard.
Our slave is called "docker_gitlab_webserver_1" our Jenkins server listens to "dockergitlab_jenkins_1" on port 8080

So let'shave a look on the configuration

Configure your new node

As you can see we have defined a rootdirectory on the slave "/var/lib/jenkins".
Create that folder a on the slave machine nd make it accessable for the master.

This configuration will use Java Webstart with Jnpl. This will do the trick on communication between slave and master.

After you save the configuration you will get a downloadlink for your "slave.jar" and a command, which you can execute on your slave

Execute on your slave

java -jar slave.jar -jnlpUrl http://dockergitlab_jenkins_1:8080/computer/dockergitlab_webserver_1/slave-agent.jnlp

This has to be executed in "/var/lib/jenkins"

Make sure you have java 7 installed

After that you can see your slave running "connected" on your jenkins master.

Great !

Install this startupscript as a service

To make that rebootsafe you have to create a service and add it to the ubuntu runlevels S and 2, 3 and 6

Create a file "/etc/init.d/jenkins-slave"

	#!/bin/bash
	#
	# /etc/init.d/jenkins-slave
	#
	# To add the script to autostart call =>
	# sudo update-rc.d jenkins-slave defaults
	#
	# To remove the script from autostart call =>
	# sudo update-rc.d -f jenkins-slave remove
	#
	### BEGIN INIT INFO
	# Provides: jenkins-slave
	# Required-Start: $local_fs $remote_fs $network $syslog $named
	# Required-Stop: $local_fs $remote_fs $network $syslog $named
	# Default-Start: 2 3 4 5
	# Default-Stop: 0 1 6
	# Short-Description: Starts jenkins-slave
	# Description: Starts jenkins-slave
	### END INIT INFO
	Name="Jenkins Slave"
	InstanceName="linux-shop-ci"
	JenkinsUrl="https://<your jenkins ur.>"
	Log="/var/log/jenkins"
	Pidfile="/var/run/jenkins-slave.pid"
	JAVA_HOME=/usr/lib/jvm/java-7-openjdk-amd64
	case "$1" in
	start)
	touch $Log
	chown shopbuilduser.root $Log
	echo "Starting $Name">>$Log
	"$JAVA_HOME/bin/java" -jar /usr/local/jenkins/slave.jar -jnlpUrl $JenkinsUrl/computer/$InstanceName/slave-agent.jnlp -noCertificateCheck 2>>$Log >>$Log &
	Pid=$!
	if [ -z $Pid ]; then
	printf "%s\n" "Fail"
	else
	echo $Pid > $Pidfile
	printf "%s\n" "Ok"
	fi
	;;
	stop)
	printf "%-50s" "Stopping $Name"
	Pid=`cat $Pidfile`
	if [ -f $Pidfile ]; then
	kill -TERM $Pid
	printf "%s\n" "Ok"
	rm -f $Pidfile
	else
	printf "%s\n" "pidfile not found"
	fi
	;;
	restart)
	$0 stop
	$0 start
	;;
	status)
	printf "%-50s" "Checking $Name..."
	if [ -f $Pidfile ]; then
	Pid=`cat $Pidfile`
	if [ -z "`ps axf | grep ${Pid} | grep -v grep`" ]; then
	printf "%s\n" "Process dead but pidfile exists"
	echo "Pidfile: $Pidfile"
	else
	echo "Running"
	echo "Pid: $Pid"
	echo "Pidfile: $Pidfile"
	fi
	else
	printf "%s\n" "Service not running"
	fi
	;;
	*)
	echo "Usage: $0 {start|stop|restart}"
	;;
	esac

view raw jenkins.slave hosted with ❤ by GitHub

sudo chmod 755 /etc/init.d/jenkins-slave
sudo chown root:root /etc/init.d/jenkins-slave

sudo update-rc.d jenkins-slave defaults 

Add it to Autostart 

sudo ln -s /usr/lib/insserv/insserv /sbin/jenkins-slave
sudo insserv jenkins-slave 

This will set correct accessrights to your service Make sure, you have replaced the parameters with your data.