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Revision as of 09:06, 17 January 2020 by Fbo (talk | contribs) (Pull Request created/updated/rechecked workflow)

Zuul Based CI

Goals

  • Bring CI infrastructure based on Zuul for projects hosted on pagure.io and src.fedoraproject.org.
  • Propose jobs and workflow of jobs around Pull Requests for Fedora packages (distgits on src.fedoraproject.org).

News

January 14, 2020

  • Thanks to an update of the Zuul's Pagure driver on softwarefactory-project.io, the zuul user no longer needs to be in the collaborator **admin** group but only in the **commit** group. The project config helper tool has been updated.

November 13, 2019

October 22, 2019 - Service is ready to be beta tested

  • This wiki page contains the process to attach a repository from src.fedoraproject.org or pagure.io to Zuul.
  • Current known Issue: Sometime, src.fedoraproject.org, does not call Zuul event hooks (https://pagure.io/fedora-infrastructure/issue/8320). Then Zuul is unable to react and run jobs from Pagure events. This does not happen with pagure.io. This is a blocker for CI which needs to be reliable in order to gain confidence, I've pinged infra folks in that issue to help us debug it.

August 28, 2019 - Created Taiga EPIC

Flock 2019

What is Zuul/Nodepool

Zuul [1] is the CI and gating system from the Open Infrastructure Project [2]. It is able to scale and handles by default features such as artifacts sharing between jobs and cross Git repositories testing. You can see Zuul in action here [3].

Below is a list of features proposed by Zuul and its companion Nodepool:

  • Event-driven pipelines based on Code-Review or Pull-Request workflow: jobs can be triggered automatically when a PR is submitted, changed, approved, merged, or when the repository is tagged.
  • CI-as-code: jobs are defined as YAML + Ansible playbooks, pipeline definitions as YAML files. Zuul reads and loads those definitions directly from Git repositories.
  • Support for jobs inheritance, jobs dependencies, jobs chaining (with artifacts sharing).
  • Speculative testing of new jobs before merging: jobs will be run as they are submitted to make sure they behave as expected.
  • Cross repositories dependencies: a jobs' workspace can include unmerged patches from other projects if specified
  • Cross provider: a jobs' workspace can include unmerged patches from other projects even when hosted on different provider like Github and Pagure.
  • Parallel job run, only capped by resources available or predefined quotas
  • Automated jobs resources lifecycle management: resources like VMs or containers needed by a given job can be defined in-repository, spawned on demand at a job's start, and destroyed when the job is finished, or held for debugging
  • Job resources support of OpenStack, OpenShift, K8S, Static nodes, AWS.
  • Well-defined, reproducible job environments to eliminate flakiness
  • Speculative testing before merging (gating): if several patches are about to land at the same time, they are tested on the repository's future state.

Until now, Zuul was only able to listen to Gerrit or Github events. Recently a new driver [4] allow Zuul to interface with Pagure as well. Pagure, Zuul and Nodepool could therefore combine into a very efficient CI/CD stack.

How to Zuul attach a Pagure repository on Zuul

Configure the repository for Zuul

In the project settings:

This helper script could be used to ease the setup: https://pagure.io/fedora-project-config/blob/master/f/tools/project-settings-helper

Add the repository into the Zuul configuration

Open a Pull Request on https://pagure.io/fedora-project-config

Edit resources/fedora.yaml and add the repository such as:

  • For a repository hosted on pagure.io:
resources:
  projects:
    Fedora-Zuul-CI:
      ...
      source-repositories:
        ...
        - repository-name


  • For a repository hosted on src.fedoraproject.org:
resources:
  projects:
    Fedora-Zuul-CI:
      ...
      source-repositories:
        ...
        - repository-name:
            connection: src.fedoraproject.org
            zuul/include: []

Once the Pull Request is accepted and merged, the repository should be available in the Zuul project list: https://fedora.softwarefactory-project.io/zuul/projects

Attach packaging jobs for a distgit repository on src.fedoraproject.org

Note that all repositories with a name that match the regexp '^rpms/.*' will get, by default, the jobs defined by the build, lint, test templates attached. Thus, if the default configuration is sufficient, then no need to edit the zuul.d/projects.yaml file as explained at the end of this section.

We have managed to provide some standard Pull Request's jobs and workflow. This idea is to reduce the amount of manual steps to propose packaging changes to Fedora by taking advantage of CI.

We propose a set of templates (a template can be seen as a workfow of jobs reacting to Pull Request events). Templates are available here https://pagure.io/fedora-zuul-jobs/blob/master/f/zuul.d/templates.yaml.

Templates configure jobs through three types of pipeline (not the same as Jenkins/Gitlab pipeline concept):

  • check: Jobs within that pipeline are triggered when a Pull Request is Opened or Updated
  • gate: Jobs within that pipeline are triggered when a Pull Request is approved (prior to be merged and closed)
  • promote: Jobs with that pipeline are triggered when a Pull Request is closed and merged

Conditions for a Pull Request to be approved:

  • All check pipelines's jobs succeeded
  • The Pull Request received the metadata tag: 'gateit'

Available jobs are (https://pagure.io/fedora-zuul-jobs/blob/master/f/zuul.d/jobs.yaml):

  • rpm-scratch-build: Runs a scratch build on Koji (Koji target based on the PR's branch) and retrieves artifacts on the test node (rpms).
  • rpm-build: Runs a regular build on Koji (Koji target based on the PR's branch)
  • rpm-lint: Runs a rpmlint on artifacts (rpms) passed from the parent job
  • rpm-rpminspect: Runs rpminspect on artifacts (rpms) passed from the parent job. The job also finds the latest build on the related Koji tag and passes it to the rpminspect job so you get the rpminspect diff.
  • rpm-test: Executes distgit embedded tests tests/tests.yml on the related Fedora node (rawhide VM for master branch, Fedora 30 VM for f30 branch, ...). It is compatible with the Fedora standard-test-interface as STI dependencies are available on the node.

Available templates are (https://pagure.io/fedora-zuul-jobs/blob/master/f/zuul.d/templates.yaml):

  • build: In the check pipeline, runs the rpm-scratch-build job in the check pipeline.
  • lint: In the check pipeline, runs, once the parent job rpm-scratch-build is done, the rpm-linter + rpm-rpminspect jobs against the rpms built by the parent job.
  • test: In the check pipeline, runs, once the parent job rpm-scratch-build is done, the rpm-test jobs against the rpms built by the parent job.
  • publish: In the gate pipeline, run a noop job (always succeed), to make the gate succeed. This makes Zuul to merge the Pull Request. Then in the promote pipeline, runs the rpm-build job (regular koji build).

To attach a template to a repository you need to open a Pull Request on https://pagure.io/fedora-zuul-jobs-config.

Edit zuul.d/projects.yaml to add:

- project:
    name: repository
    templates:
      - build
      - lint
      - gate
      - promote

repository should be like "rpms/python-gear".

Once the Pull Request is merged, the jobs of the chosen templates are attached to the repository.

Currently f29, f30, f31 and master branches are supported. Only the x86_64 arch is supported.

Sequence diagrams of the PR workflow

These diagrams show interactions between components involved in a workflow where build, lint, publish templates are used.

Pull Request created/updated/rechecked workflow

Distgit-pr-updated-workflow.png

Pull Request approved workflow

Distgit-pr-approved-workflow.png

Example of PR managed with that workflow

Nodepool nodes

Jobs are configured to execute on a Fedora VM. The default jobs we provide are configured to use the right node based on the PR target branch. For instance the rpm-test job for the master branch execute on a rawhide VM.

Projects using Zuul for the PR workflow

FAQ

Contacts

For any questions or issues you can contact fbo on freenode on #fedora-ci or #softwarefactory or you can create an issue on https://pagure.io/fedora-zuul-jobs/issues.

Also the work in progress and next steps are tracked into that Taiga EPIC: https://teams.fedoraproject.org/project/ci/epic/14