Jenkins

Overview

This installation happens on the dsb-hub.

According to Jenkins User Documentation, Jenkins is a self-contained, open source automation server which can be used to automate all sorts of tasks related to building, testing, and delivering or deploying software. It's a CI/CD platform.

Prerequisites

1. Install Java

Before installing Jenkins, ensure that Java is installed on your system:

• Update your package manager and install Java:

  sudo apt update
  sudo apt install fontconfig openjdk-17-jre

Installation Steps

1. Configure the Package Manager and Install Jenkins

• Add Jenkins to your package manager by downloading and installing the Jenkins key:

  sudo wget -O /usr/share/keyrings/jenkins-keyring.asc https://pkg.jenkins.io/debian-stable/jenkins.io-2023.key

• Add the Jenkins repository to your sources list:

  echo "deb [signed-by=/usr/share/keyrings/jenkins-keyring.asc] https://pkg.jenkins.io/debian-stable binary/" | sudo tee /etc/apt/sources.list.d/jenkins.list > /dev/null

• Update your package list and install Jenkins:

  sudo apt-get update
  sudo apt-get install jenkins

1. Enable and Start Jenkins

• Enable Jenkins to start on boot:

  sudo systemctl enable jenkins

• Start Jenkins:

  sudo systemctl start jenkins

1. Verify Jenkins is Running

• Check the status of Jenkins to ensure it's active:

  sudo systemctl status jenkins

• You should see output similar to the following if Jenkins is up and running:

  ● jenkins.service - Jenkins Continuous Integration Server
     Loaded: loaded (/usr/lib/systemd/system/jenkins.service; enabled; preset: enabled)
     Active: active (running) since [DATE]; [TIME] ago
     Main PID: 9188 (java)

Configuration Steps

1. Access Jenkins via Web Browser

• Open your web browser and go to:

  http://your_ip:8080

• You should see the Jenkins setup screen.

  

1. Retrieve the Initial Admin Password

• To proceed with the setup, you will need the initial admin password. Retrieve it by running the following command on your server:

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

• Copy the password and enter it in the password box on the web interface.

  

1. Install Suggested Plugins

• After entering the admin password, click Install suggested plugins and allow Jenkins to install the necessary plugins.

  

1. Set Up Your Admin Account

• After the plugins are installed, you’ll be prompted to set up your admin account. Enter your IP details and set up your Jenkins instance.

  

1. Configure Instance IP

• After you enter your admin information, set the URL IP address of your instance or press Not Now.

  

1. Navigate to the home page

• You should be here now.

  

Installing Jenkins Node

This section covers installing and configuring a Jenkins node on dsb-node-01.

1. Create Jenkins User

• Create a Jenkins user and set appropriate permissions:

  sudo adduser jenkins
  sudo chown -R jenkins:jenkins /home/jenkins
  sudo chmod 755 /home/jenkins
  sudo usermod -aG docker jenkins

1. Install Java

• Install Java on the Jenkins node:

  sudo apt install openjdk-17-jre-headless

1. Configure the Jenkins Node in Jenkins UI

• In Jenkins UI, navigate to Dashboard > Manage Jenkins > Nodes. Click on New Node. Select Permanent Agent and click OK.

  

• For your agent, configure the Remote root directory to /home/jenkins/agent and save the configuration.

1. Configure Jenkins Security for Agents

• In Jenkins UI, navigate to Dashboard > Manage Jenkins > Security, and scroll down until you see TCP ports for inbound agents. Select Random. Apply/Save.

  

1. Set Up the Jenkins Node

• On dsb-node-01, create the agent directory:

  cd /home/jenkins && mkdir agent

• Download the Jenkins agent JAR file:

  wget http://<jenkins-server-url>/jnlpJars/agent.jar

• Run the Jenkins agent:

  java -jar agent.jar -jnlpUrl http://<jenkins-server-url>/computer/<node-name>/slave-agent.jnlp -secret <secret-key> -workDir "/home/jenkins/agent"

NOTE: You can find the secret key on the Jenkins node configuration page.

1. Create a Systemd Service for the Jenkins Agent

• Create a new systemd service for the Jenkins agent:

  sudo nano /etc/systemd/system/jenkins-agent.service

• Add the following configuration to the service file:

  [Unit]
  Description=Jenkins Agent
  
  [Service]
  User=jenkins
  Group=jenkins
  ExecStart=/usr/bin/java -jar /home/jenkins/agent/agent.jar -jnlpUrl http://<jenkins-server-url>/computer/<node-name>/slave-agent.jnlp -secret <secret-key> -workDir /home/jenkins/agent
  Restart=always
  
  [Install]
  WantedBy=multi-user.target

• Reload systemd and start the Jenkins agent service:

  sudo systemctl daemon-reload
  sudo systemctl start jenkins-agent
  sudo systemctl enable jenkins-agent

You're Done

You're finished setting up Jenkins on your machine!