在Ubuntu上更新Jenkins主要有以下兩種方法：
wget -q -O - https://pkg.jenkins.io/debian-stable/jenkins.io.key | sudo apt-key add -和sudo sh -c 'echo deb http://pkg.jenkins.io/debian-stable binary/ /etc/apt/sources.list.d/jenkins.list'。然后更新包索引sudo apt-get update，最后升級Jenkins，可使用sudo apt-get upgrade jenkins安裝最新版，或用sudo apt-get install jenkins=<version>安裝指定版本。sudo cp /usr/share/jenkins/jenkins.war /usr/share/jenkins/jenkins.war.bak，刪除舊版本sudo rm /usr/share/jenkins/jenkins.war，再將新版本復制到相應位置sudo cp /path/to/new/jenkins.war /usr/share/jenkins/，最后重啟Jenkins服務sudo systemctl restart jenkins。
