Jenkins Maven builds on OpenShift

Short version: If you want proper Maven builds with Jenkins on OpenShift, please vote for change request JENKINS-19844.

Full story:

Today I installed Jenkins on my OpenShift account to use it as Maven release build server for some of my Java based github projects. I ran into various obstacles and partially misleading information.

Installing the Jenkins “cartridge” on the OpenShift web console was the easiest part.

Then I logged into my new Jenkins using the auto-generated “admin” login. I created a “New Item” to “Build a maven2/3 project”, i.e. a new Maven build job, and configured it: Selected “Git” SCM and pasted the github URL of the project I want to build.

At first all “Build Now” attempts failed silently, until I realized I had to go into “Manage Jenkins” – “Configure System” page to change the “# of executors” from 0 to 1.

Next thing was that the Maven installation was not found. I set up ssh access to my OpenShift Jenkins (paste contents of ~/.ssh/ from my Linux laptop into web console, then find the ssh hostname to connect) and ran a “find -name mvn /usr” on the host which located a Maven installation at /usr/share/java/apache-maven-3.0.4. I entered this in the “Maven installation” section on the Jenkins “Configure System” page.

Now I got at least some “Console output” when I clicked “Build Now” and navigated to the page of that build. The next error, however, has so far been a blocker for me. It is described here and seems to be a limitation of the Maven agent binding address in Jenkins.

I found several blogs recommending the “free-style” Jenkins job type as a workaround, instead of “maven2/3 project”. But that has many limitations and is not an acceptable solution for me.

Finally I noticed that the issue has already been reported in 2013 as JENKINS-19844 “Maven agent socket bind too inflexible (allow Jenkins in virtualized environment)”, but was closed by mistake due to a mix-up of JIRA issue numbers (19844 vs 19884).

I used my account at and reopened the Jenkins issue. Now I can only hope that someone from Jenkins committers team will care enough about this and apply the suggested code changes. Then we have to wait until OpenShift provides a Jenkins version that contains the fix.

Additional Note: I also read about other issues with Maven on OpenShift, e.g. Jenkins having no write access to ~/.m2/repository. I could not verify those problems but they seem to be fixable in ~/.m2/settings.xml, using $OPENSHIFT_DATA_DIR. Via ssh, I was able to create and edit ~/.m2/settings.xml.


Java software engineering – reference resources

Official Java and JEE

Java Technology Reference

Java Standard Edition (JSE)

Java Enterprise Edition (JEE)

The official Java tutorials

The official JEE 7 tutorial

JEE 7 Technologies index

Java language spec and JVM spec

Java community

Oracle Java community


Java Community Process (JCP)

Apache Commons Java projects


Google Guava

Trending Java projects on github

JEE and Java web servers

Apache Tomcat

JBoss Wildfly


Build and test automation

Sonatype Maven books

Jenkins documentation (wiki)

JUnit reference documentation

Source and version control

The SVN reference book

Git reference documentation

Java IDEs

Intellij IDEA documentation

Eclipse documentation

Netbeans knowledge base

Vim configuration for Java coding

Minimal Debian VM upgraded to wheezy / Jenkins with OpenJDK 7

I have upgraded my minimal Debian VM to current Debian stable (“wheezy”). It comes in OVA format which is deployable to Virtualbox or VMware.

The Debian system JDK, i.e. the location of java, javac, etc. commands in the PATH, is still OpenJDK 6 because that is the default-jdk on wheezy and the Jenkins deb packages from depend on it. In particular this means that the Tomcat / Jenkins process itself is executed by OpenJDK 6.

But my Jenkins installer now also installs OpenJDK 7 and pre-configures it as the default JDK for Jenkins jobs. That means you can now use this Jenkins instance to build your Java 7 projects, as well as older Java projects.

Please follow the step-by-step installation instructions if you want to use the VM. It consists completely of Free / Open Source software. I provide it for download “as is” without any warranty of any kind.

Jenkins on minimalistic Debian Virtualbox VM (64bit)

Update 14/Aug/2018: I no longer maintain the package mentioned and the download links below are most likely broken.

A Jenkins build server (LTS release) can now be easily installed on the minimalistic Debian VM:

  1. Download and install Virtualbox
  2. Download debian-stable-amd64-minimal.ova and import it into Virtualbox
  3. Start the “debian-stable-amd64-minimal” VM in Virtualbox
  4. If you are outside Nova Scotia, please review debian-stable-amd64-minimal.txt and adjust locale, timezone and Debian mirror based on your location
  5. Start an ssh session to localhost, port 1111 (using PuTTY, for example)
  6. Log in as user (default password is “user”)
  7. Issue “sudo jenkins” (default root password is “root”)
  8. Press enter for any questions during installation
  9. Open http://localhost:8888/ in a browser on the host OS for Jenkins web ui

You can go to “Manage Jenkins” – “Configure System” and see that JDK, Ant and Maven entries are already configured for you.

Both OpenJDK 6 and OpenJDK 7 are installed automatically for you in the VM. Please note that openjdk-6 is the Debian stable system default, while openjdk-7 is configured as the default for Jenkins build jobs.

Important: Make sure to change root and user passwords to something secure, as mentioned in debian-stable-amd64-minimal.txt.