Elastigroup Jenkins Plugin for Google Cloud Platform Preemptible VMs

Stav Maor

Product Manager

August 31, 2016

Reading Time: 3 minutes

Google Cloud

Reading Time: 3 minutes

Jenkins supports the ‘Master/Slave‘ mode, where the workload of building projects are delegated to multiple slave nodes, allowing a single Jenkins installation to host a large number of projects, or to provide different environments needed for builds/tests. This blog post describes the Master/Slave mode and how to use it.

We Are Happy To Introduce The New Spotinst’s Elastigroup Google Cloud Platform Preemptible VMs Jenkins Plugin

Spotinst’s Jenkins Plugin helps you to do more with your Jenkins setup by allowing you to automatically configure and scale a designated Google Compute Engine Preemptible VM as Slaves up and down depending on the number of jobs to be completed.
By leveraging Spotinst’s Plugin you have access to these resources with 100% uptime and 70% cost savings.

How It Works

Spotinst’s Jenkins Plugin automatically scales instances up and down based on the number of jobs in its queue. The nodes that are being provisioned run a startup script and connect as Slave nodes to the Master and immediately start run jobs.

How To Get Started

1. Generate a Spotinst API Access Token

Screen Shot 2016-06-05 at 4.51.48 PM

Once you have generated the API Access Token, copy and save it for later use inside the Jenkins Console.

Screen Shot 2016-06-05 at 4.52.01 PM

2. Create an Elastigroup with a Proper Startup Script

Now, create an Elastigroup with your proper Zone, Image, Instance Types and the following startup script

#!/bin/bash
install_deps() {
log_info “Installing dependencies”
# Install deps.
packages=$1
for package in $packages; do
installed=$(which $package)
not_found=$(echo `expr index “$installed” “no $package in”`)
if [ -z $installed ] && [ “$not_found” == “0” ]; then
log_info “Installing $package”
if [ -f /etc/redhat-release ] || [ -f /etc/system-release ]; then
yum install -y $package
elif [ -f /etc/arch-release ]; then
pacman install -y $package
elif [ -f /etc/gentoo-release ]; then
emerge install -y $package
elif [ -f /etc/SuSE-release ]; then
zypp install -y $package
elif [ -f /etc/debian_version ]; then
apt-get install -y $package
fi
log_info “$package successfully installed”
fi
done
}
INSTANCE_ID=“`curl http://169.254.169.254/latest/meta-data/instance-id`”
JENKINS_MASTER_IP=“IP:PORT”
# Install Java If not already installed
install_deps “jre”
# Get The Jenkins Slave JAR file
curl http://${JENKINS_MASTER_IP}/jnlpJars/slave.jar –output /tmp/slave.jar
# Run the Jenkins Slave JAR
java -jar /tmp/slave.jar -jnlpUrl http://${JENKINS_MASTER_IP}/computer/${INSTANCE_ID}/slave-agent.jnlp &

We recommend to use a Linux CentOS Image

3. Install Spotinst’s Jenkins Plugin and Add Your Spotinst API Token and Elastigroup ID

Login into your Jenkins console, and install the Spotinst Plugin from the available Plugins list
Once you have installed the plugin, navigate to the main "Manage Jenkins" > "Configure System" page, and scroll down to the Spotinst Section. Next, add the API Token you’ve generated in the previous step. Then click on "Validate Token", make sure that the token is valid.

Once you’ve set the Spotinst Token, scroll down near the bottom to the Cloud section and click on the "Add a new cloud" button. Then, select the "Spotinst" option.
Now, you should Specify your "Elastigroup ID" and "Idle minutes before termination"

You should be all set up to take advantage of the Spotinst Jenkins Plugin! The Jenkins Master will automatically launch new instances through the Spotinst API, and will terminate the instances as they get unused.

Best Regards,
The Spotinst Team.