[Feature Flag] Rollout of `introduce_rules_with_needs`

Summary

This FF is created to roll out a new feature: allowing needs in job rules.

MAIN-ISSUE-LINK
MR

Owners

• Team: Pipeline Authoring
• Most appropriate slack channel to reach out to: #g_pipeline-authoring
• Best individual to reach out to: @Kasia_Misirli
• PM: @dhershkovitch

Stakeholders

Expectations

What are we expecting to happen?

Users will be able to user needs with rules on jobs. See main issue for details

When is the feature viable?

Once merged and tested internally, we will release it to wider audiance.

What might happen if this goes wrong?

We turn off the feature flag.

What can we monitor to detect problems with this?

@dhershkovitch @marknuzzo could you advise which where can this improvement be monitored after release? Aka which dashboards do we usually observe once the new keyword is released?

What can we check for monitoring production after rollouts?

Consider adding links to check for Sentry errors, Production logs for 5xx, 302s, etc.

Rollout Steps

Note: Please make sure to run the chatops commands in the slack channel that gets impacted by the command.

Rollout on non-production environments

56ac1259

• Verify the MR with the feature flag is merged to master.
• Verify that the feature MRs have been deployed to non-production environments with:
  • /chatops run auto_deploy status 56ac125927bb9b97f124bb703e0d61c5e4191040
  • /chatops run feature set introduce_rules_with_needs true --project=Kasia_Misirli/km-project --staging
  • /chatops run feature set introduce_rules_with_needs 25 --actors --staging
  • /chatops run feature set introduce_rules_with_needs 25 --actors --dev
• Enable the feature globally on non-production environments.
  • /chatops run feature set introduce_rules_with_needs true --dev --staging --staging-ref
• Verify that the feature works as expected. Posting the QA result in this issue is preferable. The best environment to validate the feature in is staging-canary as this is the first environment deployed to. Note you will need to make sure you are configured to use canary as outlined here when accessing the staging environment in order to make sure you are testing appropriately.

Specific rollout on production

For visibility, all /chatops commands that target production should be executed in the #production slack channel and cross-posted (with the command results) to the responsible team's slack channel (#g_TEAM_NAME).

• Ensure that the feature MRs have been deployed to both production and canary.
  • /chatops run auto_deploy status 56ac125927bb9b97f124bb703e0d61c5e4191040
  • Depending on the type of actor you are using, pick one of these options:
    • If you're using project-actor, you must enable the feature on these entries:
    • /chatops run feature set --project=Kasia_Misirli/test-2 introduce_rules_with_needs true
      • /chatops run feature set --project=gitlab-org/gitlab,gitlab-org/gitlab-foss,gitlab-com/www-gitlab-com introduce_rules_with_needs true
      • If you're using group-actor, you must enable the feature on these entries:
        • /chatops run feature set --group=gitlab-org,gitlab-com introduce_rules_with_needs true
        • If you're using user-actor, you must enable the feature on these entries:
          • /chatops run feature set --user=<your-username> introduce_rules_with_needs true
• Verify that the feature works on the specific entries. Posting the QA result in this issue is preferable.

Preparation before global rollout

• Set a milestone to the rollout issue to signal for enabling and removing the feature flag when it is stable.
• Check if the feature flag change needs to be accompanied with a change management issue. Cross link the issue here if it does.
• Ensure that you or a representative in development can be available for at least 2 hours after feature flag updates in production. If a different developer will be covering, or an exception is needed, please inform the oncall SRE by using the @sre-oncall Slack alias.
• Ensure that documentation has been updated (More info).
• Leave a comment on the feature issue announcing estimated time when this feature flag will be enabled on GitLab.com.
• Ensure that any breaking changes have been announced following the release post process to ensure GitLab customers are aware.
• Notify #support_gitlab-com and your team channel (more guidance when this is necessary in the dev docs).
• Ensure that the feature flag rollout plan is reviewed by another developer familiar with the domain.

Global rollout on production

For visibility, all /chatops commands that target production should be executed in the #production slack channel and cross-posted (with the command results) to the responsible team's slack channel (#g_TEAM_NAME).

• Incrementally roll out the feature.
  • Between every step wait for at least 15 minutes and monitor the appropriate graphs on https://dashboards.gitlab.net.
  • If the feature flag in code has an actor, perform actor-based rollout.
    • /chatops run feature set introduce_rules_with_needs 25 --actors
    • /chatops run feature set introduce_rules_with_needs 50 --actors
    • /chatops run feature set introduce_rules_with_needs 75 --actors
    • /chatops run feature set introduce_rules_with_needs true
    • If the feature flag in code does NOT have an actor, perform time-based rollout (random rollout).
      • /chatops run feature set introduce_rules_with_needs <rollout-percentage> --random
      • Enable the feature globally on production environment.
        • /chatops run feature set introduce_rules_with_needs true
• Observe appropriate graphs on https://dashboards.gitlab.net and verify that services are not affected.
• Leave a comment on the feature issue announcing that the feature has been globally enabled.
• Wait for at least one day for the verification term.

(Optional) Release the feature with the feature flag

If you're still unsure whether the feature is deemed stable but want to release it in the current milestone, you can change the default state of the feature flag to be enabled. To do so, follow these steps:

• Create a merge request with the following changes. Ask for review and merge it.
  • Set the default_enabled attribute in the feature flag definition to true.
  • Review what warrants a changelog entry and decide if a changelog entry is needed.
• Ensure that the default-enabling MR has been included in the release package. If the merge request was deployed before the monthly release was tagged, the feature can be officially announced in a release blog post.
  • /chatops run release check <merge-request-url> <milestone>
• Consider cleaning up the feature flag from all environments by running these chatops command in #production channel. Otherwise these settings may override the default enabled.
  • /chatops run feature delete introduce_rules_with_needs --dev --staging --staging-ref --production
• Close the feature issue to indicate the feature will be released in the current milestone.
• Set the next milestone to this rollout issue for scheduling the flag removal.
• (Optional) You can create a separate issue for scheduling the steps below to Release the feature.
  • Set the title to "[Feature flag] Cleanup introduce_rules_with_needs".
  • Execute the /copy_metadata <this-rollout-issue-link> quick action to copy the labels from this rollout issue.
  • Link this rollout issue as a related issue.
  • Close this rollout issue.

WARNING: This approach has the downside that it makes it difficult for us to clean up the flag. For example, on-premise users could disable the feature on their GitLab instance. But when you remove the flag at some point, they suddenly see the feature as enabled and they can't roll it back to the previous behavior. To avoid this potential breaking change, use this approach only for urgent matters.

Release the feature

After the feature has been deemed stable, the clean up should be done as soon as possible to permanently enable the feature and reduce complexity in the codebase.

You can either create a follow-up issue for Feature Flag Cleanup or use the checklist below in this same issue.

• Create a merge request to remove introduce_rules_with_needs feature flag. Ask for review and merge it.
  • Remove all references to the feature flag from the codebase.
  • Remove the YAML definitions for the feature from the repository.
  • Create a changelog entry.
• Ensure that the cleanup MR has been included in the release package. If the merge request was deployed before the monthly release was tagged, the feature can be officially announced in a release blog post.
  • /chatops run release check <merge-request-url> <milestone>
• Close the feature issue to indicate the feature will be released in the current milestone.
• Clean up the feature flag from all environments by running these chatops command in #production channel:
  • /chatops run feature delete introduce_rules_with_needs --dev --staging --staging-ref --production
• Close this rollout issue.

Rollback Steps

• This feature can be disabled by running the following Chatops command:

/chatops run feature set introduce_rules_with_needs false