This is what I did to get a functioning Jenkins server on Ubuntu 16.04 LTS.

1) I installed the default Java that comes with Ubuntu:
sudo apt-get install default-jdk
2) Test with “java -version”

This gave me version 1.8.0_91 which worked fine for Jenkins.

3) Next I added a new repository using a PPA package.

1. wget -q -O – http://pkg.jenkins-ci.org/debian-stable/jenkins-ci.org.key | sudo apt-key add –
2. sudo sh -c ‘echo deb http://pkg.jenkins-ci.org/debian-stable binary/ > /etc/apt/sources.list.d/jenkins.list’

4) Update with “sudo apt-get update”
5) Now install Jenkins using this new repo.
sudo apt-get install jenkins
This will create a new user = jenkins user with

• home=/var/lib/jenkins
• startup script= /etc/init.d/jenkins

6) Enable jenkins to start at boot with:
sudo systemctl enable jenkins.service
other systemctl commands:

• sudo systemctl start jenkins.service
• sudo systemctl status jenkins.service
• sudo systemctl stop jenkins.service