Install #

Create user: sudo adduser jenkins
Add jenkins user as sudoer: sudo adduser jenkins sudo
Login to that user: su jenkins
Download Jenkins: wget http://mirrors.jenkins.io/war/latest/jenkins.war
Create systemd init configuration in file: sudo vim /etc/systemd/system/jenkins.service with following content:

[Unit]
Description=Jenkins Daemon

[Service]
ExecStart=/usr/bin/java -jar /home/jenkins/jenkins.war --httpPort=8081
User=jenkins

[Install]
WantedBy=multi-user.target

Reload service manager: sudo systemctl daemon-reload and you can now manage the service:

systemctl start jenkins.service      # starts the service manually
systemctl stop jenkins.service
systemctl restart jenkins.service
systemctl enable jenkins.service     # enable the service to start with system startup;
                                     # please note that it does not start the service instantly
systemctl disable jenkins.service    # disable automatic start
journalctl -u jenkins.service        # browse logs

Enable Jenkins service to boot at system start: systemctl enable jenkins.service
Run Jenkins: systemctl start jenkins.service or restart host
Log in using following port: 8081