Installing Jenkins on Linux for the DevOps Code ClearCase-Jenkins integration

Learn how to install Jenkins on Linux so that it can be integrated with DevOps Code ClearCase®.

Before you begin

Install the following items before you install Jenkins on Linux:

You must have a 64-bit Java Runtime Environment (JRE) specifically for Java 11 installed before you install Jenkins. If you do not have a JRE already, you can obtain one from Adoptium at https://adoptium.net/temurin/releases/?version=11. After you have installed Java:
- Set the path for the Java:
```
setenv PATH /opt/your-java/bin:${PATH}
```
- Set the Java path as a system environment variable:
```
setenv JAVA_HOME /opt/your-java/bin
```
You must install the ClearCase Remote Client or DevOps Code ClearCase before you install Jenkins and ensure that the system path includes /opt/devops/code/clearcase/bin.

Use the following procedure to install Jenkins on Linux for the DevOps Code ClearCase-Jenkins integration:

Download the jenkins.war file from https://get.jenkins.io/war-stable/ and place it in the home directory.
Note: ClearCase supports Jenkins LTS 2.361.4 and later.
Execute the following commands:
1. mkdir JENKINS
2. chmod 777 JENKINS
3. cd JENKINS
4. cp ~user/jenkins-2.361.4.war.
5. ls to display the jenkins-2.361.4.war file
Run the following command:
```
java -jar jenkins.war --httpPort=8080
```
Notes:
- If you want to use SSL/TLS for your Jenkins server, consult the Jenkins documentation at https://www.jenkins.io/doc/book/installing/initial-settings to use other command line flags instead of the preceding mentioned command line flag.
- During the installation of Jenkins, logs and the initial password for Jenkins are created, as shown in the following example:
```
Jenkins initial setup is required. An admin user has been created and a password generated.
Example: Please use the following password to proceed to installation:
aabbccdd
```
Tip: Note the password because you need it to unlock Jenkins.
With Jenkins hosted on part 8080, open a web browser and go to http://hostname:8080 to be navigated to where you can unlock Jenkins. See Unlocking Jenkins on Linux.

You must unlock Jenkins on Linux and customize it before you can start using it.