Learning continous integration with jenkins

All these while, I have been testing using junit test, manual testings, write script to test, or even trigger test from maven, but as many mentioned, even my buddy recommend me to look into jenkins, a continous integration for software development. Today, we are going to look into it.

So what is jenkins?

Jenkins is an open source continuous integration tool written in Java. The project was forked from Hudson after a dispute with Oracle. Jenkins provides continuous integration services for software development. It is a server-based system running in a servlet container such as Apache Tomcat. It supports SCM tools including AccuRev, CVS, Subversion, Git, Mercurial, Perforce, Clearcase and RTC, and can execute Apache Ant and Apache Maven based projects as well as arbitrary shell scripts and Windows batch commands. The primary developer of Jenkins is Kohsuke Kawaguchi.[2] Released under the MIT License, Jenkins is free software.[3]

Before we continue, let's understand the terminologies of jenkins. Below is the term which you will come across when you started with jenkins but for full list, please check out the link.

Job	A runnable task that is controlled / monitored by Jenkins
Completed Build	A build is completed, if it was started and finished with any result, including failed builds.
Successful build	A build is successful when the compilation reported no errors.
Node	Represents the physical computer running

I guess the simplest way to get yourself into jenkins is just with the command

$ java -jar jenkins.war

from terminal. However, you can also deploy within a servlet container like apache tomcat. Once started, just point your browser to jenkins with url localhost:8080. If default port 8080 is not available, you can specify --httpPort and you can find out other parameters using --help

You can also install jenkins via distribution , e.g.
rpm based distribution
deb based distribution

This article continue with the simple setup. So jenkins stores its files in $HOME/.jenkins. Right now we will create a simple project.

1. click on 'New Item' on the left navigation button.
2. add your project name. example videoOnCloud
3. select 'Build a free-style software project'
4. configure the project. See the attachment.



As a start, let's not configure any version controls system but just a simple script. We wanna learn how jenkins perform its duty. As seen here, there are a few variable configured and if you click on the link 'See the list of available environment variables', it should explain the parameters that I have configured. Go to the landing page and click build now, you should get a blue circle! Of cause, you can configure the build process using maven, ant or windows batch commands. You can also trigger remote build by executing http get to the link http://localhost:8080/job/videoOnCloud/build

So that's it. You should now have very basic using jenkins, try enable version controls system in your build configuration.