How to setup Continous Integration for GitLab with Jenkins

Hi, I'd like to share with you how I got my Jenkins CI set up for my private GitLab projects. This is more like a sheet of notes of mine, but I hope it'll help someone as I haven't found any good tutorial for Jenkins+Gitlab on the web yet :D

generate ssh keys on own server -> PUBLIC and PRIVATE ( no passphrase )
go to GitLab profile settings -> SSH keys -> add PUBLIC ssh key to GitLab = this will allow your Jenkins server to access your GitLab
also create full access GitLab API access token for Jenkins on your gitlab profile settings and keep it

install Git + GitLab plugin on Jenkins ( make sure they are enabled (ticked) in Jenkins !!!)