# apt-get upgrade
sudo apt-get update -y
sudo apt-get upgrade -y
# install JDK (필요하다면)
sudo apt install openjdk-11-jdk -y
# add gpg key for jenkins installation
wget -q -O - https://pkg.jenkins.io/debian-stable/jenkins.io.key | apt-key add -
# add repository address to /etc/apt/sources.list.d
sudo sh -c 'echo deb https://pkg.jenkins.io/debian-stable binary/ > /etc/apt/sources.list.d/jenkins.list'
# upgrade package again
sudo apt-get update -y
# install jenkins
sudo apt-get install jenkins -y
sudo systemctl start jenkins
sudo systemctl stop jenkins
sudo nano /etc/default/jenkins