Openshift Jenkins does not appear to send Node label during build - jenkins

Question

I'm trying to get HA Openshift Origin working on CentOS 6.5 (Nightly packages, but may be a few days out) but one of the last things to get working is Jenkins.
When I start a build of an application, manually or after a git push, I get the following error:
Jun 06, 2014 2:24:52 PM hudson.plugins.openshift.OpenShiftCloud provision
INFO: Provisioning new node for workload = 2 and label = null in domain stu
Jun 06, 2014 2:24:52 PM hudson.plugins.openshift.OpenShiftCloud provision
INFO: Cancelling build - Label is null
Jun 06, 2014 2:24:52 PM hudson.plugins.openshift.OpenShiftCloud cancelBuild
INFO: Cancelling build
Jun 06, 2014 2:24:52 PM hudson.plugins.openshift.OpenShiftCloud cancelItem
INFO: Cancelling Item
Jun 06, 2014 2:24:52 PM hudson.plugins.openshift.OpenShiftCloud cancelItem
WARNING: Build null rawbldr has been canceled
Jun 06, 2014 2:24:52 PM hudson.triggers.SafeTimerTask run
SEVERE: Timer task hudson.slaves.NodeProvisioner$NodeProvisionerInvoker#f01ba81 failed
java.lang.UnsupportedOperationException: No Label
at hudson.plugins.openshift.OpenShiftCloud.provision(OpenShiftCloud.java:402)
at hudson.slaves.NodeProvisioner.update(NodeProvisioner.java:281)
at hudson.slaves.NodeProvisioner.access$000(NodeProvisioner.java:51)
at hudson.slaves.NodeProvisioner$NodeProvisionerInvoker.doRun(NodeProvisioner.java:366)
at hudson.triggers.SafeTimerTask.run(SafeTimerTask.java:54)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:304)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:178)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:744)
Looking at the code of the Jenkins plugin: https://github.com/openshift/jenkins-cloud-plugin/blob/master/src/main/java/hudson/plugins/openshift/OpenShiftCloud.java#L353 it just looks like the value of the label set in the job config isn't received for some odd reason, so a builder gear doesn't get spun up.
This is very similar to this old Q from Openshift Online, but it's unclear from the comments the actual cause other than "maintenance":
Cant build on openshift jenkins
Everything else that I've tried appears to work fine, so I'm not sure if it's a bug, or misconfiguration somewhere.
Thanks
Openshift-origin nightly packages
Jenkins 1.564 (1.564-1.1)
openshift-origin-cartridge-jenkins (1.22.1-1.git.0.3f73f10.el6)
openshift-origin-cartridge-jenkins-client (1.21.1-1.git.0.93d6489.el6)
Openshift Jenkins cloud plugin 1.4 (0.6.36-0.el6oso)
I have replicated the issue in a vagrant machine, so am currently assuming it's the combination of packages I'm running.
Could someone running from the nightly repos please specify which package versions of each of the above they have running without issue? Thanks

Answer 1

I got the same issue (that is how I got here), and the workaround for me was to go to Manage Jenkins > Configure system and then set the "# of executors" field to 1.

Answer 2

I've tried a few different versions of Jenkins with the latest Openshift cloud plugin
1.510 - works, but a bit old
1.554 - works if you set JENKINS_JAR_CACHE_PATH env var (see https://github.com/openshift/jenkins-cloud-plugin/issues/30)
1.564 - hits the above issue, doesn't ever spin up a gear let alone start the Jenkins slave
I'm currently running Jenkins v1.554 and setting an env var with the following Puppet
file { '/etc/openshift/env/JENKINS_JAR_CACHE_PATH':
ensure => present,
content => '/tmp/',
require => File['/etc/openshift/env/'],
owner => 'root',
group => 'root',
mode => '0644',
}
The Openshift guys will apparently be using v1.554 by default in the near future anyway.