How To Install Jenkins on Ubuntu 22.04

Introduction

Jenkins is an open-source automation server that automates the repetitive technical tasks involved in the continuous integration and delivery of software. Jenkins is Java-based, installed from Ubuntu packages or by downloading and running its web application archive (WAR) file — a collection of files that make up a complete web application to run on a server.

In this tutorial you will install Jenkins on Ubuntu 22.04, start the development server and create an administrative user to get started exploring Jenkins automation. At the end of this tutorial you will have an unsecured Jenkins server ready for a development deployment. To secure your installation for production, follow the guide How to Configure Jenkins with SSL Using an Nginx Reverse Proxy on Ubuntu 22.04.

Prerequisites

To follow this tutorial, you will need:

• One Ubuntu 22.04 server configured with a non-root sudo user and firewall by following the Ubuntu 22.04 initial server setup guide. We recommend starting with at least 1 GB of RAM. Visit Jenkins’s “Hardware Recommendations” for guidance in planning the capacity of a production-level Jenkins installation.
• Oracle JDK 11 installed, following our guidelines on installing specific versions of OpenJDK on Ubuntu 22.04.

Step 1 — Installing Jenkins

The version of Jenkins included with the default Ubuntu packages is often behind the latest available version from the project itself. To ensure you have the latest fixes and features, use the project-maintained packages to install Jenkins.

First, add the repository key to your system:

wget -q -O - https://pkg.jenkins.io/debian-stable/jenkins.io.key |sudo gpg --dearmor -o /usr/share/keyrings/jenkins.gpg

The gpg --dearmor command is used to convert the key into a format that apt recognizes.

Next, let’s append the Debian package repository address to the server’s sources.list:

sudo sh -c 'echo deb [signed-by=/usr/share/keyrings/jenkins.gpg] http://pkg.jenkins.io/debian-stable binary/ > /etc/apt/sources.list.d/jenkins.list'

The [signed-by=/usr/share/keyrings/jenkins.gpg] portion of the line ensures that apt will verify files in the repository using the GPG key that you just downloaded.

After both commands have been entered, run apt update so that apt will use the new repository.

sudo apt update

Finally, install Jenkins and its dependencies:

sudo apt install jenkins

Now that Jenkins and its dependencies are in place, we’ll start the Jenkins server.

Step 2 — Starting Jenkins

now that Jenkins is installed, start it by using systemctl:

sudo systemctl start jenkins.service

Since systemctl doesn’t display status output, we’ll use the status command to verify that Jenkins started successfully:

sudo systemctl status jenkins

If everything went well, the beginning of the status output shows that the service is active and configured to start at boot:

Output
● jenkins.service - Jenkins Continuous Integration Server
     Loaded: loaded (/lib/systemd/system/jenkins.service; enabled; vendor preset: enabled)
     Active: active (running) since Mon 2022-04-18 16:07:28 UTC; 2min 3s ago
   Main PID: 88180 (java)
      Tasks: 42 (limit: 4665)
     Memory: 1.1G
        CPU: 46.997s
     CGroup: /system.slice/jenkins.service
             └─88180 /usr/bin/java -Djava.awt.headless=true -jar /usr/share/java/jenkins.war --webroot=/var/cache/jenkins/war --httpPort=8080

Now that Jenkins is up and running, adjust your firewall rules so that you can reach it from a web browser to complete the initial setup.

Step 3 — Opening the Firewall

To set up a UFW firewall, visit Initial Server Setup with Ubuntu 22.04, Step 4- Setting up a Basic Firewall. By default, Jenkins runs on port 8080. Open that port using ufw:

sudo ufw allow 8080

sudo ufw allow OpenSSH
sudo ufw enable

Check ufw’s status to confirm the new rules:

sudo ufw status

You’ll notice that traffic is allowed to port 8080 from anywhere:

Output
Status: active

To                         Action      From
--                         ------      ----
OpenSSH                    ALLOW       Anywhere
8080                       ALLOW       Anywhere
OpenSSH (v6)               ALLOW       Anywhere (v6)
8080 (v6)                  ALLOW       Anywhere (v6)

With Jenkins installed and a firewall configured, you have completed the installation stage and can continue with configuring Jenkins.

Step 4 — Setting Up Jenkins

To set up your installation, visit Jenkins on its default port, 8080, using your server domain name or IP address: http://your_server_ip_or_domain:8080

You should receive the Unlock Jenkins screen, which displays the location of the initial password:

In the terminal window, use the cat command to display the password:

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

Copy the 32-character alphanumeric password from the terminal and paste it into the Administrator password field, then click Continue.

The next screen presents the option of installing suggested plugins or selecting specific plugins:

We’ll click the Install suggested plugins option, which will immediately begin the installation process.

When the installation is complete, you’ll be prompted to set up the first administrative user. It’s possible to skip this step and continue as admin using the initial password from above, but we’ll take a moment to create the user.

Enter the name and password for your user:

You’ll receive an Instance Configuration page that will ask you to confirm the preferred URL for your Jenkins instance. Confirm either the domain name for your server or your server’s IP address:

After confirming the appropriate information, click Save and Finish. You’ll receive a confirmation page confirming that “Jenkins is Ready!”:

Click Start using Jenkins to visit the main Jenkins dashboard:

At this point, you have completed a successful installation of Jenkins.

Conclusion

In this tutorial, you installed Jenkins using the project-provided packages, started the server, opened the firewall, and created an administrative user. At this point, you can start exploring Jenkins.

When you’ve completed your exploration, follow the guide How to Configure Jenkins with SSL Using an Nginx Reverse Proxy on Ubuntu 22.04 to protect your passwords, as well as any sensitive system or product information that will be sent between your machine and the server in plain text to continue using Jenkins.

To learn more about what you can do using Jenkins, check out other tutorials on the subject:

• How to Build Android Apps with Jenkins
• How To Set Up Continuous Integration Pipelines in Jenkins on Ubuntu 16.04