Installing Jenkins on your Raspberry Pi?

Jenkins is a popular open source automation server that allows you to easily set up CI/CD pipelines for building, testing and deploying software projects. With its vast plugin ecosystem and easy configuration, Jenkins is a great choice for automating workflows for software development.

Installing Jenkins on your Raspberry Pi?

Benefits of Running Jenkins on a Raspberry Pi

The Raspberry Pi is a low-cost, credit card sized computer that is perfect for running 24/7 applications. Here are some of the main benefits of installing Jenkins on a Raspberry Pi:

Cost Effective

Raspberry Pis are inexpensive computers, making them very cost effective for running Jenkins continuously without requiring a large investment in hardware.

Energy Efficient

The Raspberry Pi consumes very little power, which means it won’t lead to a spike in your electricity bills to keep Jenkins running at all times.

Compact Size

The small form factor of the Raspberry Pi means it can sit discreetly wherever you want without taking up much space.

Always On

The Raspberry Pi allows keeping Jenkins running 24/7 so it’s always available whenever you need to create a new build or view reports.

Step-by-Step Guide to Installing Jenkins

Follow this straight-forward guide for installing and setting up the latest version of Jenkins on your Raspberry Pi.

Install Java 8

Jenkins requires Java, so first install Java 8 with the following commands:

sudo apt update

sudo apt install openjdk-8-jdk

Verify the installation with:

java -version

Install Jenkins

Next, we’ll install Jenkins using the official repository maintained by Jenkins project.

First, add the repository key:

wget -q -O – https://pkg.jenkins.io/debian-stable/jenkins.io.key | sudo apt-key add –

Add the repository address:

sudo sh -c ‘echo deb https://pkg.jenkins.io/debian-stable binary/ > 

    /etc/apt/sources.list.d/jenkins. List’

Update apt and install Jenkins:

sudo apt update

sudo apt install jenkins

This installs the latest version of Jenkins from the official repository.

Start Jenkins

To start the Jenkins service, enter:

sudo systemctl start jenkins

Check that it started properly with:

sudo systemctl status jenkins

If all is well, the service should be active.

Jenkins runs on port 8080 by default. To access the web interface, open http://<pi_ip_address>:8080 in any browser.

You should see the getting started page for Jenkins.

Unlock Jenkins

When you access Jenkins for the first time, it will prompt you to unlock it by entering the administrator password.

To get this password, enter the following command on your Pi:

sudo cat /var/lib/jenkins/secrets/initialAdminPassword

Copy the 32-character alphanumeric password from the terminal and paste it into the Administrator password field in the browser. Click Continue.

You have now unlocked Jenkins!

Customize Jenkins

On the next screen you will be asked to install some plugins. You can choose to install the suggested plugins, or select specific ones.

Once the plugins are installed, you will be asked to create your first admin user. Provide username, password and other details to set up your admin account.

Jenkins is now ready! You can proceed to create jobs and build awesome projects.

Optimizing Jenkins Performance on the Pi

Here are some tips for improving Jenkins performance on Raspberry Pi:

Assign Swap Space

Adding some swap space allows Jenkins to function more smoothly when load is high. In a terminal enter:

sudo nano /etc/dphys-swapfile

Change CONF_SWAPSIZE=100 to CONF_SWAPSIZE=1024 to assign 1 GB swap space. Save and reboot.

Optimize Java

By default Java grabs extra RAM which can be limited to improve performance:

sudo nano /etc/default/jenkins

Set these parameters:

JAVA_OPTS=”-Xmx256m”

JENKINS_JAVA_OPTIONS=”-Djava.awt.headless=true”

Save the file and restart Jenkins.

Use a Custom Image

Standard Raspberry Pi OS includes extra services that consume resources. A custom Pi image just for Jenkins exists to optimize the system.

Cache Builds

Using caching plugins like Cache Directory can save build time by caching dependencies locally.

With a few tweaks like above, you can build an efficient Jenkins server.

Conclusion

Installing Jenkins on a Raspberry Pi is straightforward and provides an always-on automation server for CI/CD pipelines. With optimizations to assign swap space, limit Java RAM usage, and using a trimmed OS image the Pi can handle a high workload.

By following the steps outlined in this guide, you will have Jenkins up and running on your Raspberry Pi to manage all your build automation and deployments.

Frequently Asked Questions

Q: Is the installation process the same on other Pi models?
A: Yes, the installation process is largely the same across newer Raspberry Pi models like Pi 3B+, Pi 4 etc. Java and Jenkins versions remain the same.

Q: How do I backup or migrate my Jenkins data from my Pi?
A: Jenkins stores all job configurations and build history in it’s home directory at /var/lib/jenkins. You can directly copy this directory to backup Jenkins or migrate it to a new device.

Q: Does Jenkins run well on the latest Pi 4?
A: Yes, the more powerful processor in Pi 4 handles Jenkins extremely well. Additional RAM in Pi 4 models further helps with better performance for higher build loads.

Q: What’s the recommended OS for running Jenkins on Pi?
A: Raspberry Pi OS Lite is ideal as it’s more streamlined without unnecessary packages occupying RAM and other resources for better Jenkins performance.

Q: What steps can I take to secure Jenkins?
A: Disable the frontend for the Jenkins CLI service, use role based access for users, restrict dangerous methods for anonymous users and set IP address restrictions for admin access to improve security.

Q: Can I access Jenkins remotely from my PC or other devices?
A: Yes, as long as your Raspberry Pi hosting Jenkins is connected to your local network, you can access the Jenkins UI through the Pi’s IP address. Port 8080 needs to be opened.

Q: Is Jenkins platform independent?
A: Yes, Jenkins server can run on any machine and operating system supporting Java including Windows, Mac, Linux etc. Agents connect remotely to builds.

Q: How do I backup Jenkins data periodically?
A: Install the Github + Google Backup plugin to automatically backup your Jenkins config to Github gists and Google Drive for redundancy.

Q: Can I still access other Pi services with Jenkins running?
A: Certainly! Jenkins runs as an isolated service on port 8080 allowing you to run other software services and access the Pi desktop without conflicts.

Q: I’m facing Java heap issues on the Pi. How can I fix this?
A: In /etc/default/Jenkins, add this line: JAVA_OPTS=’-Xmx512m’ to increase the Java heap size to 512 MB which improves stability on the Pi.

Q: Why do I get permission errors when installing Jenkins?
A: The Jenkins package needs to run installation and configuration scripts during setup. Make sure you run all installation commands with sudo or as root user.

Q: Does Jenkins auto update itself on the Pi?
A: Yes, Jenkins on the Pi checks weekly for updates and will prompt you to restart itself upon finding a new version from the package manager repository.

Q: Is Jenkins free to use?
A: Yes, Jenkins is 100% open source and forever free to use or extend as you need by modifying the code. Paid enterprise extensions are available too.

Q: Can the Pi handle high loads with Jenkins?
A: For small teams and lighter pipelines the Pi works very well. For larger enterprise loads, a more powerful machine is recommended to improve stability under heavy load.

Q: How do I set up agents to build Java, Python, etc. codebases?
A: Install the NodeJS, Java, Python etc. SDKs on the Raspberry Pi or a separate machine and connect them as agents in Jenkins with either the Jenkins native agents or Docker containers.

Q: Is it better to run Jenkins agents on separate machines?
A: Yes, using the Pi as the controller and running agents on faster, more powerful machines allows taking advantage of their compute resources for builds and tests.

Q: Why am I facing the Jenkins is fully up message repeatedly?
A: This happens if the Java process is crashing. Assign more RAM and heap space to Java in /etc/default/jenkins and ensure the Pi model has enough resources.

Q: How do I migrate my existing Jenkins setup to my Pi?
A: Simply copy over the critical Jenkins home directory from the old installation containing jobs, config and data over to your Pi’s Jenkins home directory.

Q: Can I run Jenkins and other software like web servers on the same Pi?
A: Yes, just make sure to allocate enough resources like RAM, CPU cores etc. using the cgroups kernel feature to prevent those from starving Jenkins.

Q: Does Jenkins work reliably on Pi compared to x86 computers?
A: When configured correctly with enough resources, Jenkins on arm64 chips like the Pi 4/3 offers excellent stability comparable to x86 machines.

Q: Will closing the terminal session kill a running Jenkins process?
A: No, Jenkins runs as a daemon system process detached from any terminal or user session so it will continue running unaffected if you close terminals.

Leave a Comment