Can a master jenkins run jobs on remote jenkins?

Question

We are migrating from CruiseControl.NET to Jenkins just to be in sync with a partner so we don't have two different CI scripts. We are trying to setup Jenkins to do something similar to what we had CruiseControl doing which was have a centralized server invoke projects (jobs in jenkins) on remote build machines.

We have multiple build machines associated to a single project so when we build the project from the centralized CI server it would invoke the projects on the remote CI servers. The remote CI servers would pull the version from the centralized CI server project.

In CruiseCruise control we setup a project that would do a forceBuild on the remote projects. The projects on the build machines used a remoteProjectLabeller to retrieve the version number so they were always in sync.

To retrieve the master build number:

<labeller type="remoteProjectLabeller">
  <project>MainProject</project>
  <serverUri>tcp://central-server:21234/CruiseManager.rem</serverUri>
</labeller>

To invoke the remote projects:

<forcebuild>
    <project>RemoteBuildMachineA</project>
    <serverUri>tcp://remote-server:21234/CruiseManager.rem</serverUri>
    <integrationStatus>Success</integrationStatus>
</forcebuild>

So far in jenkins i've setup a secondary server as a slave using the java web start but I don't know how I would have the master jenkins invoke the projects setup on the slaves.

Can I setup Jenkins to invoke projects (jobs) on slaves?

Can I make the slaves pull the version number from the master?

EDIT -

Let me add some more info.

• The master, and remote build machine slaves are all running Windows.
• We had the central master CruiseControl kick off the remote projects at the same time so they ran concurrently and would like to have the same thing with jenkins if possible.

Answer 1

Jenkins has the concept of build agents, which could perhaps fit your scenario better - there's a master that triggers the build and slaves that perform it. A build can be then restricted to some categories of slaves only (e.g. if it depends on a specific software, not present on all agents). All data is managed centrally by the master, which I believe is what you are trying to achieve.

Answer 2

In Jenkins it is not possible to trigger a build on a slave, i.e. where a build runs is not controlled by the one who triggers it. It is controlled by the settings of the job itself. Each job has a setting called "Restrict where this job can run".

In your case you would probably have two jobs: A and B. A would be restricted to run on "master" and B would be configured to run on "slavename". Then all that is left to do is for A to trigger B.

But you had further constraints: You want A and B check out the same version from version control and you want A and B to run in parallel. There are many ways to accomplish that but the easiest is probably to define a multi-configuration job.

There is no way to turn an existing free-style job into a multi-configuration job, so you will have to make a new job.

• Choose New job
• Choose Build new multi-configuration project. Add a name.
• Under Configuration Matrix, open the "Add axis" drop down.
• Choose Slaves
• Check master and the slave
• Add the SCM information and build step(s)

When the job runs, it runs on both the master and the slave. Jenkins makes sure they build from the same source version.

Answer 3

From the /jenkins/computer url, you can add, remove, and reconfigured "nodes" which are either local or remote "build agents".

The Jobs can then be constrained to run on particular build agents, or follow various rules to select the appropriate build agent out of the available agents.

Answer 4

I was thinking about Jenkins too much like CruiseControl where the job is defined on the remote machine. So in Jenkins the remote projects are defined on the master and delegated to a remote machine via an agent.

I used the Java Web Start agent installed as a windows service on the remote machines. To have specific jobs run on specific remote machines I defined each remote node with a unique label in its slave configuration. To bind specific jobs to specific slaves I used the slave's label in each job configuration ("Restrict where this project can be run").

To trigger the jobs with a single master job I created a free style job that only is set to "Build other projects" and provided a comma separated list or project names. This job builds the downstream jobs in parallel.

I'm still looking for a way to send a master build number to the downstream jobs to keep them in sync always. (This is used to version DLLs and such.)