KodeKloud Notes

In this lesson, we’ll dive into Jenkins—an open-source automation server—and walk through the post-installation setup. You’ll learn how to verify the service, retrieve the initial admin password, unlock Jenkins, install plugins, and complete the setup wizard.

What is Jenkins?

Jenkins is a leading open-source automation server for continuous integration and delivery (CI/CD). It leverages a rich plugin ecosystem to build, test, and deploy your applications automatically. Jenkins supports multiple project types:

Freestyle: Classic build jobs
Multi-configuration: Matrix builds across multiple environments
Multibranch Pipeline: Auto-discovers branches with Jenkinsfile
Simple Pipeline: Defines build steps in code

Throughout this course, we’ll focus on a Simple Pipeline, which uses a collection of scripted jobs to automate software delivery from version control to production.

Jenkins plugins can be installed via:

Installation Method	Description
Plugin Manager (UI)	Browse and install from the Jenkins dashboard
Jenkins CLI	Use `java -jar jenkins-cli.jar` to install plugins
Remote REST API (Automation)	Script plugin installation using REST calls

Why Remote REST API?

Automating plugin installation with the Remote REST API ensures consistent environments, especially in Infrastructure as Code workflows.

The image is a presentation slide about Jenkins, an open-source automation tool, explaining its use of plugins for continuous integration and listing some plugins with their versions.

1. Verifying the Jenkins Service

On your VM, Jenkins runs on port 8080 by default. Verify the service status:

sudo systemctl status jenkins

Expected output:

● jenkins.service - LSB: Start Jenkins at boot time
   Loaded: loaded (/etc/init.d/jenkins; generated)
   Active: active (exited) since Tue 2021-06-15 05:07:43 UTC; 1h 39min ago

2. Accessing the Jenkins Web UI

Open your browser and navigate to:

http://<your-vm-dns-name>:8080

Default Port

If you changed the default port in your install script, adjust the URL accordingly.

On first access, Jenkins prompts for the initial admin password. Retrieve it from the VM:

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

Copy the output and paste it into the Unlock Jenkins screen.

3. Installing Suggested Plugins

After unlocking Jenkins, select Install suggested plugins to set up common integrations such as Git, Pipeline, and folders. This bulk installation simplifies your initial configuration.

Plugin Installation Time

Depending on your network and VM resources, this step may take several minutes.

The image shows a Jenkins setup wizard screen with options to "Install suggested plugins" or "Select plugins to install." It is displayed on a computer screen with a browser and taskbar visible.

The image shows a computer screen displaying a "Getting Started" setup wizard for Jenkins, with various plugins and options listed. There is also a small video call window in the top right corner showing a person.

4. Creating the First Admin User

Once the plugins are in place, Jenkins prompts you to create an admin account. Provide:

Username
Password
Full name
Email address

Save your new credentials to proceed.

The image shows a setup wizard for creating the first admin user in Jenkins, with fields for username, password, full name, and email address. A person is visible in a small circular video feed in the top right corner.

5. Configuring the Jenkins Instance URL

Set the Jenkins URL used by external systems (e.g., Git webhooks). Enter your VM’s DNS name or static IP, then save.

The image shows a Jenkins setup wizard screen for instance configuration, with a URL field and options to save or skip the setup. A person is visible in a small video call window at the top right corner.

6. Completing the Setup

With the URL configured, click Start using Jenkins to finish the wizard.

The image shows a browser window with a Jenkins setup completion message, indicating that Jenkins is ready to use. There is a button labeled "Start using Jenkins."

7. Exploring the Jenkins Dashboard

You’ve arrived at the Jenkins dashboard (version 2.289.1). From here, you can:

Create and configure new pipelines
Manage credentials and plugins
Set up distributed builds

Later in this course, we’ll automate the installation of nine essential plugins using the Remote REST API script.

The image shows a Jenkins dashboard interface with options to start building a software project and set up a distributed build. There is also a small video call overlay in the top right corner.

Links and References

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