Jenkins : Xvfb Plugin

Plugin Information

View Xvfb on the plugin site for more information.

What is it?

Lets you control Xvfb virtual frame buffer X11 server with each build. It starts Xvfb before the build starts, and stops it with the build. This is very useful if your build requires X11 access, for instance runs tests that require GUI.

New feature in version 1.1.0 - Jenkins Pipeline support

With 1.1.0 Pipeline support has landed, you can now use Xvfb to wrap other pipeline steps:

node {
  wrap([$class: 'Xvfb']) {
    ... your steps here
  }
}

New feature in version 1.0.16 - Parallel build mode

Use I’m running this job in parallel on same node when running multiple slaves (Jenkins nodes) on the same machine to prevent collisions when jobs are run on same-numbered executors.

New feature in version 1.0.11 - Labels

Use Start only on nodes labeled option for multi platform builds.

New feature in version 1.0.9 - auto display name (on newer Xvfb versions)

Use Let Xvfb choose display name option with Xvfb that supports displayfd option to choose the display number automatically by Xvfb.

Getting help

Please use the users mailing list, Stackoverflow or ask on one of the chats. This page was not designed for support, please do no comment on it asking for help. If you encounter bugs or issues please create a ticket in the issue tracker, it would be really nice if you would research first and see if the issue you're experiencing is due to the Xvfb Jenkins plugin or with the Xvfb itself and the version of Xvfb you're using.

Usage

The plugin starts and stops the Xvfb virtual framebuffer X11 server so your jobs can use X11 displays in headless environments such as servers, or when dedicated X11 display is required for each job.

Start by going to Manage Jenkins / Global Tool Configuration on Jenkins version 2.0 or Manage Jenkins / Configure System on earlier version and setup your Xvfb installation. You need to give it a arbitrary name like default Xvfb and directory in which the Xvfb executable is located like /usr/X11R6/bin. Unfortunately there is no support for automatic installation of Xvfb. As of version 1.1.0 you can define a single Xvfb tool installation or have a installation named "default" and the jobs are going to run even if you don't define what installation to use in the job configuration.

Typically you would use the defaults, which are that display numbers, a unique number that is used to identify each X11 display (you might see them shown as :0, :1 or such), are based on the current Jenkins executor number (the number you see next to the running job in the Build Executor Status box). This is fine if display numbers corresponding to the executor numbers are available for Jenkins to use. If they're not you have several options:

  • use a fixed display number (Xvfb specific display name) by which you guarantee that the specified display number is reserved for the specified Jenkins job
  • use display numbers based on executor numbers but offset by some number (Xvfb display name offset) by which you reserve a range of display numbers for the specified Jenkins job, for instance if you use offset of 100, display names will be 100 and greater, up to the number of executors on a particular Jenkins executor (i.e. slave or master depending on where the job is run)
  • leave the choice of display number to Xvfb (Let Xvfb choose display name) – if your Xvfb version supports it, by which Xvfb chooses a free display number on its own

Project Configuration

On the job configuration page, enable the "Start Xvfb before the build, and shut it down after." under the Build Environment.

If you want to customize defaults click on Advanced... button.

  • Xvfb installation lets you choose Xvfb installation to use, these are configured by the Jenkins administrator in the Tools section of Jenkins configuration. By default the first defined installation is used.
  • Let Xvfb choose display name Uses the -displayfd option of Xvfb by which it chooses its own display name by scanning for an available one. This option requires a recent version of xserver, check your installation for support. Useful if you do not want to manage display number ranges but have the first free display number be used.
  • Xvfb specific display name lets you customize what displayname should be created, enter a number here and that number prefixed by : will be the displayname (e.g. :1). If none is given display name is based upon Jenkins executor number increased by 1, or the configurable Xvfb display name offset.
  • I’m running this job in parallel on same node - if you have multiple slaves on the same machine, the build number will be generated based on the ordinal of the machine multiplied by 100 plus the executor number and any offset configured. Be careful Xvfb will not work with this enabled if you're running more than 595 nodes and 35 executors per node.
  • Start only on nodes labeled lets you specify via label expressions on what node(s) to start Xvfb.
  • Timeout in seconds lets you specify the number of seconds before letting the build progress. Since Xvfb is started in background, certain builds might fail because Xvfb was not started quick enough, with this the build is paused the for specified seconds to let Xvfb startup. The default is not to pause the build.
  • Xvfb screen changes the screen resolution and pixel depth, it needs to be in WxHxD format (i.e. 1600x1200x24). The default is 1024x768x24.
  • Xvfb display name offset lets you specify a offset i.e. a number that will be added to the job's executor number that will form the display name used. This is handy if you run other X servers (Xvfb, Xvnc or similar) in order to ensure that display numbers do not overlap.
  • Xvfb additional options lets you specify any additional Xvfb command line options you might need.
  • Log Xvfb output redirects output of Xvfb into job log, useful if you need to troubleshoot Xvfb starting/stopping.
  • Shutdown Xvfb with whole job, not just with the main build action keeps Xvfb running for post build steps.

Jenkins configuration

Jenkins administrator needs to define the Xvfb tool installation.

The directory in which to find Xvfb executable can be left blank, then PATH is searched to find the executable.

Version History

Version 1.1.3 (Mar 20, 2015)

JENKINS-32039 "screen" default does not work
JENKINS-33206 Xvfb plugin doesn't remember "Log Xvfb output" set via the configuration page
JENKINS-33288 Xvfb error does not fail build

Thanks to Mark Leaky, Nathan Smith and Francis De Brabandere for reporting issues!

Version 1.1.2 (Dec 10, 2015)

JENKINS-32005 Xfvb plugin doesn't remember displayname set via the configuration page

Thanks to Adriaan Wisse for reporting the issue!

Version 1.1.1 (Dec 5, 2015)

PULL#8 Screen name was not being set from the configuration.

Thanks to Daniel Borges for the pull request!

Version 1.1.0 (Nov 24, 2015)

Added support for the Pipeline Plugin

Version 1.0.16 (Feb 8, 2015)

JENKINS-26848 Does not actually randomize DISPLAY

Thanks to Jo Shields for reporting and testing!

Version 1.0.15 (Jan 20, 2015)

JENKINS-26504 Cannot run low numbered builds with xvfb in Jenkins 1.597
JENKINS-26505 java.lang.IllegalArgumentException: Prefix string too short org.jenkinsci.plugins.xvfb.XvfbBuildWrapper.launchXvfb(XvfbBuildWrapper.java:484) duplicate

Thanks to Jonathan Price and mturra for reporting the issue!

Version 1.0.13 (Oct 1, 2014)

Prevent NPE when NullConverter registered pull request by Aleksandr Zhuikov

Thanks to Aleksandr Zhuikov for the pull request!

Version 1.0.12 (Jun 2, 2014) - bug-fix release

  • JENKINS-23267 NullPointerException in XvfbBuildWrapper.setUp when configured without node label restrictions

Thanks to Alexander Clausen, Jarosław Strzelecki & elygre for reporting and suggesting fix.

Version 1.0.11 (Jun 1, 2014)

Thanks to cowwoc for reporting and testing!

Version 1.0.10 (Apr 23, 2014)

  • JENKINS-22719 Xvfb plugin does not start before release plugin
  • Zombie slaying on Jenkins master failure

Thanks to Zoltan Nagy and Dmitry Katsubo for reporting and testing!

Version 1.0.9 (Mar 5, 2014)

  • JENKINS-20758 Xvfb processes remain after slave disconnect
  • JENKINS-19950 DISPLAY variable is not overwritten when it already exists
  • JENKINS-21548 Xvfb failure does not fail build
  • New feature that lets Xvfb to pick the display name

Thanks to Marc Günther, Richard Cross and Jonathan Rogers for reporting and beta testing!

Version 1.0.8 (Jun 29, 2013)

  • JENKINS-18094 Xvfb plugin doesn't write any error message in build log

Thanks to Aleksey Alekseev for reporting and testing!

Version 1.0.7 (Dec 9, 2012)

Thanks to Yves Langisch for reporting the feature request!

Version 1.0.6 (Nov 5, 2012)

  • JENKINS-15638 Xvfb 'display name offset' defaults to 0, not 1 as described, if unset

Thanks to Fredrik Vihlborg for re-reporting issues!

Version 1.0.5 (Oct 30, 2012)

  • JENKINS-15638 Xvfb 'display name offset' defaults to 0, not 1 as described, if unset

Thanks to Fredrik Vihlborg for reporting issues!

Version 1.0.4 (Oct 24, 2012)

  • JENKINS-14483 Remaining Xvfb processes in matrix jobs
  • pull request #2 Make sure the random display name is always more than 0.
  • JENKINS-15608 Xvfb 'specific displayname' selects a random display between 0..100, not 1..100.

Thanks to Thorsten Kahler for reporting the issue and exemplary patience in testing, JeroenVanHab for the pull request and Fredrik Vihlborg for reporting the issue!

Version 1.0.3 (Sep 15, 2012)

Thanks to Brian Sipos and Daniel Piorkowski for reporting issues!

Version 1.0.2 (Mar 12, 2012)

  • Field to add additional options to Xvfb command line (JENKINS-13046)

Version 1.0.1 (Jan 29, 2012)

  • Initial release