安装方法所在网址：   https://wiki.jenkins-ci.org/display/JENKINS/Installing+Jenkins+on+Ubuntu

在安装jenkins之前，ubutun上需要安装有jdk和jre。建议安装 openjdk-7-jre 和openjdk-7-jdk 版本 。

安装：

wget -q -O - https://jenkins-ci.org/debian/jenkins-ci.org.key | sudo apt-key add -

sudo sh -c 'echo deb http://pkg.jenkins-ci.org/debian binary/ > /etc/apt/sources.list.d/jenkins.list'

sudo apt-get update

sudo apt-get install jenkins

更新：

sudo apt-get update

sudo apt-get install jenkins

安装完成后用浏览器   http://localhost:8080/    就可以打开。

安装完成后将进程拉起：
service jenkins start/stop/restart
出现如下提示：

Starting jenkins (via systemctl):  Job for jenkins.service failed. 
See 'systemctl status jenkins.service' and 'journalctl -xn' for details.

                                                           [FAILED]
官网提示是因为没有安装java所导致。
官网地址：
https://wiki.jenkins-ci.org/display/JENKINS/Installing+Jenkins+on+Red+Hat+distributions
Note: if you get the following error message, ensure that Java has been installed:

Starting jenkins (via systemctl):  Job for jenkins.service failed. 
See 'systemctl status jenkins.service' and 'journalctl -xn' for details.
                                                           [FAILED]