simultaneous instances of the same hudson/jenkins job

Question

I would like a way for individual users to send a repo path to a hudson server and have the server start a build of that repo. I don't want to leave behind a trail of dynamically created job configuration. I'd like to start multiple simultaneous instances of the same job. Obviously this requires that the workspaces different for the different instances. I believe this isn't possible using any of the current extensions. I'm open to different approaches to what I'm trying to accomplish.

I just want the hudson server to be able to receive requests for builds from outside sources, and start them as long as there are free executors. I want the build configuration to be the same for all the builds except the location of the repo. I don't want to have dozens of identical jobs sitting around with automatically generated names.

Is there anyone out there using Hudson or Jenkins for something like this? How do you set it up? I guess with enough scripting I could dynamically create the necessary job configuration through the CLI API from a script, and then destroy it when it's done. But I want to keep the artifacts around, so destroying the job when it's done running is an issue. I really don't want to write and maintain my own extension.

Answer 1

This should be pretty straightforward to do with Jenkins without requiring any plugins, though it depends on the type of SCM that you use.
It's worth upgrading from Hudson in any case; there have certainly been improvements to the features required to support your use case in the many releases since becoming Jenkins.

You want to pass the repo path as a parameter to your build, so you should select the "This build is parameterized" option in the build config. There you can add a string parameter called REPO_PATH or similar.

Next, where you specify where code is checked-out from, replace the path with ${REPO_PATH}.
If you are checking out the code — or otherwise need access to the repo path — from a script, the variable will automatically be added to your environment, so you can refer to ${REPO_PATH} from your shell script or Ant file.

At this point, when pressing Build Now, you will be prompted to enter a repo path before the build will start. As mentioned in the wiki page above, you can call the buildWithParameters URL to start a build directly with the desired parameter, e.g. http://server/job/myjob/buildWithParameters?REPO_PATH=foo

Finally, if you want builds to execute concurrently, Jenkins can manage this for you by creating temporary workspaces for concurrent builds. Just enable the option "Execute concurrent builds if necessary" in your job config.

The artifacts will be available, the same as any other Jenkins build. Though probably you want to manage how many recent artifacts are kept; this can be done by checking "Discard Old Builds", and then under Advanced…, you can select enter a value for "Max # of builds to keep with artifacts".