Ubuntu Jenkins版本升級主要有以下兩種方式：
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
sudo apt install jenkins -y
sudo apt install jenkins=<version> # 需先通過`apt-cache madison jenkins`查看可用版本
sudo systemctl restart jenkins
sudo cp /usr/share/jenkins/jenkins.war /usr/share/jenkins/jenkins.war.bak
sudo rm /usr/share/jenkins/jenkins.war
sudo cp /path/to/new/jenkins.war /usr/share/jenkins/
sudo systemctl restart jenkins
/var/lib/jenkins）。參考來源：
