Update the system first sudo apt update

Jenkins requires java to run so install openjdk distribution sudo apt install openjdk-11-jre

curl -fsSL https://pkg.jenkins.io/debian-stable/jenkins.io-2023.key | sudo tee \  
/usr/share/keyrings/jenkins-keyring.asc > /dev/null


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

sudo apt-get update

sudo apt-get install jenkins

sudo apt-get update -y

sudo apt-get install jenkins -y

Installation finished now enable the jenkins service sudo systemctl enable jenkins

Check if jenkins is running sudo systemctl status jenkins

Note: Accessing Jenkins dashboard if it is running through ec2 instance

Add the above inbound rules to access successfully by default port 22 which is for ssh is enabled add the remaining type like HTTP, HTTPS also custom tcp 8080 too.

After the above changes dashboard is accessible at port 8080, for ec2 type public_ip4_address:8080

The above dashboard is visible, now to access admin password go to terminal and type sudo cat /var/lib/jenkins/secrets/initialAdminPassword

Install suggested plugins, create admin user and now its ready.