Code changed in jenkins
User: Jesse Glick
Path:
COMPATIBILITY.md
http://jenkins-ci.org/commit/workflow-plugin/b07c6a491c37edd69162c3be75bf22fa43066356
Log:
JENKINS-28386 Noting.

Probable workaround (untested):

node('master') {
  dir('/path/on/master/1') {
    stash 'master-stuff'
  }
}
node('slave') {
  dir('/path/on/slave/1') {
    unstash 'master-stuff'
  }
  dir('/path/on/slave/2') {
    stash 'slave-stuff'
  }
}
node('master') {
  dir('/path/on/master/2') {
    unstash 'slave-stuff'
  }
}

Note that this requires an executor on the master. Which is probably a good thing: in a secured Jenkins instance, there should be none, which would prevent someone from abusing this system to steal secrets from the master.

Thanks jglick, that is a great work-around! It almost seems like Pipeline has this feature natively and perhaps this plugin support isn't needed? I couldn't seem to get it to stash something outside of the workspace (either by putting absolute paths or relative ../../ paths), and copy-to-slave prefers to copy things from userContent, so the work-around for me was to do something like this:

node('master') {
  sh "ln -sf ${env.JENKINS_HOME}/userContent ."
  stash includes: "userContent/foo/*", name: "master-stuff"
}
node('slave') {
  unstash 'master-stuff"
  sh "ls userContent/foo"
}

I will not offer advice on anything that involves nonzero master executors, which is inherently dangerous and unsupportable.

That makes sense for public Jenkins; I don't see anything inherently dangerous about this in a Jenkins with authentication inside an intranet/VPC (though I agree it is less secure). Regardless, you can also accomplish a similar thing by running a separate agent on the master with a different user or in a container, and thus having the unix security model to isolate things as desired. This would allow you to Stash world-readable files on the master without exposing secrets, unless there are other concerns I'm not aware of, which I fully admit there might be.