Hot deploy in Jetty a war file built by Jenkins

We use Jenkins to build our application as a war file and we wanted to deploy it in a Jetty server to provide a manual testing environment.
So, we installed Jetty on our Ubuntu machine using 'sudo apt-get jetty libjetty-extra'
By default, when you copy a war file to Jetty webapps directory, nothing happens because Jetty scans this directory only at startup. So, we could stop/start Jetty daemon but it requires granting some privileges to the user running Jenkins and also we may want to deploy more than one application without stoppîng the ones that are already running.

Another solution is to use Jetty's ContextDeployer hot deploy.

This means editing /etc/jetty/jetty.xml and setting the scanInterval of ContextDeployer to lowest possible value: 1 second and then restart Jetty.

<Call name="addLifeCycle">
<New class="org.mortbay.jetty.deployer.ContextDeployer">
<Set name="contexts"><Ref id="Contexts"/></Set>
<Set name="configurationDir"><SystemProperty name="jetty.home" default="."/>/contexts</Set>
<Set name="scanInterval">1</Set>

Now we must create a context file for our war file in /etc/jetty/contexts directory. Let's call it myapp.xml and let's point it to the location of the war file from last successful build in Jenkins.

<?xml version="1.0"  encoding="ISO-8859-1"?>
<!DOCTYPE Configure PUBLIC "-//Mort Bay Consulting//DTD Configure//EN" "http://jetty.mortbay.org/configure.dtd">
<Configure class="org.mortbay.jetty.webapp.WebAppContext">
<Set name="contextPath">/myapp</Set>
<Set name="war">/var/lib/jenkins/jobs/MyProject/lastSuccessful/archive/trunk/myapp/target/myapp-0.0.1-SNAPSHOT.war</Set>

In order to deploy we just have to update our context file which can be easily done by executing 'touch /etc/jetty/contexts/myapp.xml'. We can then add it as a step in our main job in Jenkins if we want want continuous deployment or we can create a separate job if we want to control when we deploy a new version.

1 commentaire:

Rolf a dit…

Thanks for sharing your experience. Btw the ContextDeployer is now deprecated and has been replaced by the DeploymentManager which works equally welll.