http://www.cnblogs.com/melody-emma/p/6026622.html

You need to modify the permission for jenkins user so that you can run the shell commands. You can install the jenkins as as service (download the rpm package), You might need to change the ports because by default it runs http on 8080 and AJP on 8009 port. 

Following process is for CentOS
1. Open up the this script (using VIM or other editor):

vim /etc/sysconfig/jenkins

2. Find this $JENKINS_USER and change to “root”:

$JENKINS_USER="root"

3. Then change the ownership of Jenkins home, webroot and logs:

chown -R root:root /var/lib/jenins chown -R root:root /var/cache/jenkins chown -R root:root /var/log/jenkins

4) Restart Jenkins and check the user has been changed:

service jenkins restart ps -ef | grep jenkins

Now you should be able to run the Jenkins jobs as the root user and all the shell command will be executed as root.