How to setup Jenkins service/system.d to automatically run at server reboot

I ended up getting the jenkins war file from the instructions at https://www.digitalocean.com/community/tutorials/how-to-install-jenkins-on-ubuntu-18-04. The jenkins war file installed at /usr/share/jenkins.

I made a copy of the jenkins/jobs folder that I had been using for the past month for the builds run through cloudbees jenkins. Deleted all references to cloudbees jenkins, installed new jenkins from the link, and copied back in my jobs folder.

This version of jenkins came with an init.d script, /etc/init.d/jenkins which was exactly what I needed to have jenkins start up automatically when the server reboot. Tested it by restarting the server, and when it came back alive again, Jenkins started right up.

So, I never did get the war file of Jenkins from Cloudbees going, but I found a workaround that got the job done that I needed it to.