Changes/GatingRawhidePackages

Gating Rawhide - Single package updates

Summary

We want to gate packages on test results before they can land in rawhide. This will reduce the amount of broken dependency, uninstallable packages and broken composes leading to a more stable rawhide as well as less work on the infrastructure and rel-eng teams to keep composes working.

This project will be split in two phases, at first only single package updates will be supported, in a second stage, we will add support for multi-packages updates.

This proposal is about the phase 1 of this project.

Owner

• Name: Pierre-Yves Chibon
• Email: pingou - pingoured.fr

People who are/will be involved in this:

• Coordinator: Pierre-Yves Chibon
• Bodhi: Randy Barlow and Aurélien Bompard
• Fedora CI: Dominik Perpeet
• Release notes owner:

Current status

• Targeted release: N/A
• Last updated: 2019-02-28

Detailed Description

Querying the Bodhi database, it was revealed that 95% of all our updates involve a single package.

To be exhaustive, here are the exact number found:

Of all time:

  Single build updates: 123,657 (94.1%)
  Multi  build updates:   7,766 ( 5.9%)

  Total:                131,423

Per release:

  Fedora 29:

  Single:  4,675 (93.7%)
  Multi:     316 ( 6.3%)

  Fedora 28:

  Single:  9,153 (94.5%)
  Multi:     536 ( 5.5%)

  EPEL 7:

  Single: 12,664 (94.0%)
  Multi:     814 ( 6.0%)

When considering gating rawhide package updates on test results, we need to consider two workflows: single package updates, multi-package updates. This proposal only considers the single package updates workflow. [ Another proposal] will be submitted in the future to support the multi package updates workflow.

At first we want to build the system allowing to gating rawhide, packagers will opt-in into gating using greenwave's opt-in gating mechanism as they want. We will also offer a way to opt-out so packages depending on other packages can still be built without issues.

We do not aim at making any tests mandatory as part of these proposals. Once the two proposals have been deployed it will be up to the community and likely FESCo to decide if they would like to enforce some rules on all packages and which ones.

Workflows

• 

  Single package update with gating

Benefit to Fedora

• As more packagers opt-into gating and add tests to their packages, rawhide becomes more stable
• More stable rawhide will lead to easier composes and a smoother release process
• Ability to use chain-build in rawhide and stable releases

Scope

The scope of this work is adding a mechanism to gate single package updates before they enter the rawhide buildroot (and thus become accessible to others) so broken packages are kept out and cannot affect other packages or the compose until they are fixed by their maintainers.

The CI system, the tests and the decision on which tests are used to gate upon are out of scope for the present document.

• Proposal owners: pingou will be coordinating the work among the different stack holder

• Other developers:
  • Bodhi developers: Implement the needed changes
  • infrastructure: deploy the new version of bodhi and the new koji plugin

• Release engineering: #Releng issue number (a check of an impact with Release Engineering is needed)

• Policies and guidelines: Once the entire system is in place, FESCo may want to set a policy on distribution-wide gating (ie: tests that would be enforced for all packages in the distributions). This is however out of scope of this proposal.

• Trademark approval: N/A (not needed for this Change)

Application impacted

Bodhi

• Single package update
  • We will need to write a message-bus listener that will automatically create a bodhi update for each package built in the rawhide-gated tag.
  • We will need to write a message-bus listener to automatically push bodhi updates created for rawhide that have passed CI (the decision being announced by Greenwave).

• Bodhi will comment on the updates when greenwave's decision about an update is known
  • This will notify users about the test results and the corresponding gating status.

Greenwave / WaiverDB

Nothing should change for these tools but we will have to confirm this and test in staging that they behave as expected.

CI system

Nothing should change for the CI system but we will have to confirm this and test in staging that they behave as expected.

Upgrade/compatibility impact

N/A

How To Test

Single package update

1. Add tests to a package you maintain in Fedora using the CI/Quick_Start_Guide documentation (see the full CI documentation for more information).
2. Update your package in rawhide
3. Ensure that the bodhi update is automatically created
4. Check that the tests have properly ran (see the Tests tab in the bodhi update)
5. Ensure that the bodhi update went through to rawhide once the tests passed

User Experience

Single package update

   fedpkg clone rpms/foobar
   cd foobar/
   vim foobar.spec
   git commit -am "Git commit message"
   fedpkg build
   

If the CI tests pass, the package will land in rawhide, if they fail the user will be able to go to bodhi to see what failed and why as well as waiving the failed tests if needed.

Multi package update with single package update gating

   fedpkg clone rpms/foobar
   cd foobar/
   vim foobar.spec
   git commit -am "Update of foobar to update foo to 1.2"
   fedpkg push
   fedpkg build --target=rawhide-candidate
   cd ..
   fedpkg clone rpms/foobaz
   cd foobaz
   vim foobaz.spec
   git commit -am "Update of foobaz to update foo to 1.2"
   fedpkg push
   fedpkg build --target=rawhide-candidate
   cd ..
   fedpkg clone rpms/foo
   cd foo
   vim foo.spec
   git commit -am "Update foo to 1.2"
   fedpkg push
   fedpkg build --target=rawhide-candidate

Users are practically by-passing the gating process by specifying a specific build target.

Dependencies

• Bodhi
  • bus listener to automatically create updates when a build happens in rawhide
  • bus listener to automatically push updates who passed gating according to greenwave
  • comment on updates about gating status change/announce to notify packagers about it

Contingency Plan

We can keep doing rawhide as we are doing it today.

Documentation

To be written/updated

List of documentation pages to update:

• https://fedoraproject.org/wiki/Updates_Policy
• https://fedoraproject.org/wiki/Package_maintenance_guide
• https://fedoraproject.org/wiki/Package_update_HOWTO
• https://docs.fedoraproject.org/en-US/packaging-guidelines/