Installing on Linux in Jenkins - Visual Walkthrough

Process Flow - Installing on Linux

Update package index

↓

Install Java (Jenkins dependency)

↓

Add Jenkins repository key

↓

Add Jenkins repository

↓

Update package index again

↓

Install Jenkins package

↓

Start and enable Jenkins service

↓

Check Jenkins status

↓

END

This flow shows the step-by-step process to install Jenkins on Linux, starting from updating packages, installing dependencies, adding Jenkins repository, installing Jenkins, and finally starting the service.

Execution Sample

Jenkins

sudo apt update
sudo apt install openjdk-11-jdk -y
wget -q -O - https://pkg.jenkins.io/debian-stable/jenkins.io.key | sudo apt-key add -
sudo sh -c 'echo deb https://pkg.jenkins.io/debian-stable binary/ > /etc/apt/sources.list.d/jenkins.list'
sudo apt update
sudo apt install jenkins -y
sudo systemctl start jenkins
sudo systemctl enable jenkins
sudo systemctl status jenkins

This code installs Jenkins on a Debian-based Linux system by updating packages, installing Java, adding Jenkins repo, installing Jenkins, and starting the Jenkins service.

Process Table

Step	Command	Action	Result	System State Change
1	sudo apt update	Update package index	Package lists updated	Package index refreshed
2	sudo apt install openjdk-11-jdk -y	Install Java	Java installed	Java runtime available
3	wget -q -O - https://pkg.jenkins.io/debian-stable/jenkins.io.key | sudo apt-key add -	Add Jenkins repo key	Key added successfully	System trusts Jenkins repo
4	sudo sh -c 'echo deb https://pkg.jenkins.io/debian-stable binary/ > /etc/apt/sources.list.d/jenkins.list'	Add Jenkins repo	Repo added to sources.list.d	Jenkins repo available for apt
5	sudo apt update	Update package index again	Package lists updated with Jenkins repo	Package index refreshed with Jenkins packages
6	sudo apt install jenkins -y	Install Jenkins package	Jenkins installed	Jenkins software installed
7	sudo systemctl start jenkins	Start Jenkins service	Jenkins service started	Jenkins running
8	sudo systemctl enable jenkins	Enable Jenkins service at boot	Jenkins enabled on startup	Jenkins auto-start configured
9	sudo systemctl status jenkins	Check Jenkins service status	Active (running)	Confirmed Jenkins is running
10	-	End of installation	-	Jenkins installed and running

💡 Installation completes after Jenkins service is running and enabled on system boot.

Status Tracker

Variable	Start	After Step 2	After Step 6	After Step 7	Final
package_index	outdated	updated	updated	updated	updated
java_installed	no	yes	yes	yes	yes
jenkins_repo_added	no	no	yes	yes	yes
jenkins_installed	no	no	yes	yes	yes
jenkins_service_status	stopped	stopped	stopped	running	running
jenkins_enabled_on_boot	no	no	no	no	yes

Key Moments - 3 Insights

Why do we run 'sudo apt update' twice during installation?

The first 'apt update' refreshes the package list before installing Java. After adding the Jenkins repository, we run 'apt update' again to include Jenkins packages in the package list, as shown in steps 1 and 5 in the execution_table.

What happens if Java is not installed before Jenkins?

Jenkins requires Java to run. If Java is missing, Jenkins installation or startup will fail. Step 2 ensures Java is installed before Jenkins installation in step 6.

What does 'sudo systemctl enable jenkins' do?

It configures Jenkins to start automatically when the system boots. This is shown in step 8 where Jenkins is enabled on startup.

Visual Quiz - 3 Questions

Look at the execution_table, at which step is Jenkins service started?

A Step 6

B Step 7

C Step 8

D Step 9

💡 Hint

Check the 'Action' column for 'Start Jenkins service' in the execution_table.

According to variable_tracker, when does 'jenkins_installed' change from 'no' to 'yes'?

A After Step 2

B After Step 7

C After Step 6

D After Step 8

💡 Hint

Look at the 'jenkins_installed' row and see when it changes value.

If we skip adding the Jenkins repository (step 4), what will happen when running 'sudo apt install jenkins'?

A Installation fails because Jenkins package is not found

B Jenkins installs successfully from default repos

C Java will not be installed

D Jenkins service will start automatically

💡 Hint

Refer to step 4 and 6 in the execution_table about repository addition and package installation.

Concept Snapshot

Installing Jenkins on Linux:
1. Update package index: sudo apt update
2. Install Java: sudo apt install openjdk-11-jdk -y
3. Add Jenkins repo key and repo
4. Update package index again
5. Install Jenkins: sudo apt install jenkins -y
6. Start and enable Jenkins service
Key: Java must be installed first; repo must be added before Jenkins install.

Full Transcript

To install Jenkins on Linux, first update the package index to get the latest package info. Then install Java, which Jenkins needs to run. Next, add the Jenkins repository key and repository to your system so apt can find Jenkins packages. Update the package index again to include Jenkins packages. Install Jenkins using apt. Finally, start the Jenkins service and enable it to start automatically on boot. Check the service status to confirm Jenkins is running. This process ensures Jenkins is properly installed and ready to use.