Installing Jenkins on RHEL 8 is a straightforward process. Here's a step-by-step guide

Introduction 

Jenkins is an open-source automation server widely used for continuous integration (CI) and continuous delivery (CD) pipelines in software development. Originally developed as Hudson in 2004 and later forked into Jenkins in 2011, it has become a cornerstone tool for automating various stages of the software development lifecycle.

At its core, Jenkins allows developers to automate tasks such as building, testing, and deploying applications, thereby facilitating rapid and reliable software delivery. It achieves this through a vast ecosystem of plugins, enabling integration with a wide range of tools and technologies.

Jenkins provides a web-based interface for easy configuration and management of jobs, pipelines, and nodes, making it accessible to both developers and DevOps teams. With features like distributed builds, version control system integration, and extensive plugin support, Jenkins empowers teams to adopt agile practices, improve collaboration, and accelerate the delivery of high-quality software.

Prerequisites

Before installing Jenkins on RHEL, you need to ensure that you have the following:

A running instance of RHEL

A user account with sudo privileges

Java installed on your system

1: Install Java

Jenkins requires Java to be installed on the system.

You can install Java using the following command:

sudo yum install java-1.8.0-openjdk-devel

2. Update System Packages: Before installing any new software, it's a good practice to update your system's package repository and installed packages. Open a terminal and run the following commands:

   sudo yum update

3. Install Java: Jenkins requires Java to run. You can install OpenJDK, which is an open-source implementation of the Java Platform.

   sudo yum install java-11-openjdk-devel

4. Add Jenkins Repository: Jenkins is not available in the default RHEL repositories, so you need to add the Jenkins repository to your system.

   sudo wget -O /etc/yum.repos.d/jenkins.repo https://pkg.jenkins.io/redhat-stable/jenkins.repo

5. Import Jenkins Repository Key:

   sudo rpm --import https://pkg.jenkins.io/redhat-stable/jenkins.io.key

6. Install Jenkins: Now, you can install Jenkins using yum.

   sudo yum install jenkins

7. Start Jenkins Service: Once Jenkins is installed, start the Jenkins service and enable it to start on boot.

   sudo systemctl start jenkins

   sudo systemctl enable jenkins

8. Configure Firewall: If your firewall is enabled, you need to allow traffic on port 8080, which is the default port for Jenkins.

   sudo firewall-cmd --zone=public --permanent --add-port=8080/tcp

   sudo firewall-cmd --reload

9. Access Jenkins: Jenkins should now be running on your server. You can access it by navigating to your server's IP address or domain name followed by port 8080 in a web browser:

   http://your_server_ip_or_domain:8080

10. Unlock Jenkins: On your first visit, Jenkins will ask you to unlock it by providing an initial password. This password can be found in the Jenkins server's filesystem. Use the following command to retrieve it:

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

11. Follow the Setup Wizard: Once you have entered the initial password, Jenkins will guide you through the setup process, including installing recommended plugins and creating an admin user.

12. Start Using Jenkins: After completing the setup wizard, Jenkins is ready for use. You can start creating your projects and automating your workflows.

That's it! You've successfully installed Jenkins on RHEL 8.