Using oVirt Standard-CI with Gerrit

When projects are hosted in oVirt's Gerrit server, the oVirt CI system can provide automated building, testing and release services for them if they comply with the Build and Test standards.

Automated functionality of the oVirt CI system

When projects are configured to use the oVirt CI system, the system responds automatically to various event as they occur in the project source code in Gerrit.

Here are actions that the CI system can be configured to carry out automatically:

  1. The 'check-patch' stage is run automatically when new non-draft patch sets are pushed to Gerrit. Note that the CI system can skip testing for trivial changes sure as changes that are made only to the commit message.
  2. The 'check-merged' stage is run automatically when patches are merged.
  3. The 'build-artifacts' stage is run automatically when patches are merged, and those artifacts are then submitted to the oVirt change queues for automated system testing with ovirt-system-tests.
  4. An automated check for upstream source changes followed by an invocation of the 'poll-upstream-sources' is performed periodically.

Manual functionality of the oVirt CI system

Certain parts of the CI system can be activated manually by adding certain trigger phrases as comments on Gerrit patches.

The following table specifies which trigger phrases can be used:

Trigger phrase What it does
ci test please Run the 'check-patch' stage
ci check please Run the 'check-patch' stage
ci build please Run the 'build-artifacts' stage
ci re-merge please Re-run post-merge behaviour. *

* This should only be used on the latest merged patch of a project. Using this on an unmerged or an older patch will yield unexpected resuts!

Note: The 'please' keyword can actually be omitted or placed between 'ci' and the second keyword.

The contributors white list

Gerrit is configured to allow anyone to send patches to any project. This is a reasonable policy for an open source project, but it can pose a risk to the CI system because one can send a patch with a malicious script.

To mitigate this risk, the CI system only checks patches by white-listed oVirt members. The white list is stored as a plain text file containing E-Mail addresses in the jenkins-whitelist repository.

For new oVirt contributors, patches should be sent to the repository to add ther addresses to the white list files. Care should be taken to review patches for malicios code before doing so.

Configuring the oVirt CI system for a project

When a project complies with the oVirt Build and Test standards, the CI system can gather most of the information it needs in order to build and test the project from the project's own source code repository.

To make the CI system process a Gerrit project one needs to simply inform the system about the project's existence.

To do that, the project name needs to be specified under the right server section in the jobs/confs/projects/standard-pipelines.yaml file in the jenkins repo. Here is an example of how the section for the 'oVirt' production Gerrit server looks like:

- project:
    name: oVirt-standard-pipelines-gerrit
    gerrit-server: ''
      - engine-db-query
      - fabric-ovirt


      - vdsm
      - '{project}_standard-gerrit-jobs'

Note: Given the amount of projects listed in that section, we make an effort to keep the list in alphabetical order.

Note: Because 'poll-upstream-sources' are executed periodically and not as a response to Gerrit events, configuring them take a little more work and is discussed below.

Once a patch to modify the YAML file is merged The YAML file will be read by the jenkins-job-builder tool and CI jobs will be created on the oVirt Jenkins server to provide the desired CI functionality.

You can find more information about tools you can use to edit and test YAML files for jenkins-job-builder here.

Configuring poll-upstream-sources jobs for projects

To enable automated source code updates to a project (E.g. to update upstream commit mentioned in the upstream-sources.yaml file), one needs to create a scheduled poll-upstream-sources job for each branch that needs to get automated updates.

To create one or more jobs for a project, one needs to add a YAML section like the following to the jobs/confs/projects/standard-poll-stage-pipelines.yaml file in the jenkins repo:

- project:
    name: ovirt-engine-metrics_standard-poll-upstream-sources
      - ovirt-engine-metrics
      - master
      - '{project}_{branch}_standard-poll-upstream-sources'

All the branches that need to be updated must be listed under the branch section.

If multiple projects have the exact same branch configuration, they can be listed together under the project section.