05/03/2019 - JENKINS, LINUX
You can use commands below to install Jenkins on Debian Stretch (9).
$ sudo apt update
$ sudo apt install default-jre
$ wget -q -O - https://pkg.jenkins.io/debian/jenkins.io.key | sudo apt-key add -
$ sudo sh -c 'echo deb http://pkg.jenkins.io/debian-stable binary/ > /etc/apt/sources.list.d/jenkins.list'
$ sudo apt update
Then you can go to http(s)://www.your-jenkins-server-url:8080
finalise the Jenkins setup.