All projects in oVirt CI are built today post merge, using the ‘build-artifacts’ stage from oVirt’s CI standards.
This ensures that all oVirt projects are built and deployed to oVirt repositories and can be consumed by CI jobs, developers or oVirt users.

However, on some occasions a developer might need to build his project from an open patch.
Developers need this capability in order to to examine the effects of their changes on a full oVirt installation before merging those changes.
On some cases developers may even want to hand over packages based on un-merged patches to the QE team to verify that a given change will fix some complex issue or to preview a new feature on its early stages of development.

The Current Build Option

Until now, to build rpms from a patch, a developer needed to use a custom Jenkins job, which was only available to ovirt-engine and only for master branch. Another option was to try and build it locally using standard CI ‘mock’ script which will use the same configuration
as in CI. For full documentation on how to use ‘mock-runner’, checkout the Standard CI page.

The New Build Option

To ease and simplify the build from patch option, the oVirt infra team added a new feature to the oVirt’s CI standards framework called ‘build on demand’.

It allows any oVirt developer to trigger a build from any open patch just by adding the comment ‘ci please build’ on the patch in Gerrit.
It will then trigger a ‘build-artifacts-on-demand’ job on jenkins which will build rpms from the patch, but not publish them to any repo.

How Do I Enable It For My oVirt Project ?

Enabling the ‘build-on-demand’ feature to an oVirt project is simple as adding a single line to the project standard yaml file, just add the following line to your ‘build-artifacts’ section, under ‘jobs’:

  - '{project}_{version}_{stage}-on-demand-{distro}-{arch}'

For a full example on how to send a patch for enabling it,
Checkout an example Patch which adds on-demand builds to four different projects.

What Else Can I Do With It ? (Hint: OST)

Maybe the most interesting and valuable thing you can do with the new feature, is to run the oVirt system tests suit on
the open patch (something that was possible only post merge until today, or required complex actions to do it manually).

Running the OST suite with your newly created RPMs requires also just one line of code, here’s how you do it:

After the job you triggered finished running in Jenkins, use the Jenkins build URL you got (Example)
as a parameter to to run OST on your laptop.
From the OST root dir, run the following to run basic master suite for e.g:

./ -s basic_suite_master

For more info and help on using this new feature, feel free to come and ask us on
For more info on oVirt system tests, checkout the Project Documentation Page

Happy Building!