[Feature flag] Rollout of `ci_runner_limits_override`
Summary
This issue is to allow flexibility in the rollout the feature on production,
that is currently behind the ci_runner_limits
feature flag. The ci_runner_limits_override
FF will allow disabling ci_runner_limits
for namespaces/projects that require it.
Owners
- Team: Verify:Runner
- Most appropriate slack channel to reach out to:
#g_runner
- Best individual to reach out to: @pedropombeiro
- PM: @DarrenEastman
Stakeholders
The Rollout Plan
- Initial rollout on GitLab.com to create exclusions for the upcoming [Feature flag] Rollout of
ci_runner_limits
(#329438). - Usual rollout as described in [Feature flag] Rollout of
ci_runner_limits
(#329438)
Testing Groups/Projects/Users
-
pedropombeiro/playground
project
Expectations
What are we expecting to happen?
We expect that when this FF is enabled for an actor, it overrides ci_runner_limits
in the following way:
- CI runner limits only apply when
ci_runner_limits
is enabled andci_runner_limits_override
is disabled for an actor.
We'll start by enabling the ci_runner_limits_override
FF for namespaces we know we don't want to be affected by ci_runner_limits
(since those namespaces are known to contain more than 1000 runners). Later we'll start rolling out ci_runner_limits
and watching for customer complaints. We'll be able to add specific namespaces to the exclusion list by enabling the ci_runner_limits_override
FF on those namespaces, but if it gets too unwieldy, it might be better to disable ci_runner_limits
altogether and rethink the deployment with new learnings.
For the record, I will be on vacations from Aug 9th-20th so if things get out of hand during that period, the simplest solution is to just rollback the ci_runner_limits
FF deployment.
What might happen if this goes wrong?
This FF is meant to allow rolling back changes brought by ci_runner_limits
, the only thing that might go wrong is if this doesn't actually perform the override as advertised.
What can we monitor to detect problems with this?
Rollout Steps
Rollout on non-production environments
-
Ensure that the feature MRs have been deployed to non-production environments. -
/chatops run auto_deploy status <merge-commit-of-your-feature>
-
-
Enable the feature globally on non-production environments. -
/chatops run feature set ci_runner_limits_override true --dev
-
/chatops run feature set ci_runner_limits_override true --staging
-
-
Verify that the feature works as expected. Posting the QA result in this issue is preferable.
Preparation before production rollout
-
Ensure that the feature MRs have been deployed to both production and canary. -
/chatops run auto_deploy status <merge-commit-of-your-feature>
-
-
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). -
Announce on the feature issue an estimated time this will be enabled on GitLab.com. -
If the feature might impact the user experience, notify #support_gitlab-com
and your team channel (more guidance when this is necessary in the dev docs). -
If the feature flag in code has an actor, enable it on GitLab.com for testing groups/projects. -
/chatops run feature set --<actor-type>=<actor> ci_runner_limits_override true
-
-
Verify that the feature works as expected. Posting the QA result in this issue is preferable.
Global rollout on production
-
Enable the feature flag on selected namespaces and projects as determined by the thread in https://gitlab.com/gitlab-org/gitlab/-/issues/321368#note_637969756. -
/chatops run feature set --group=<group path> ci_runner_limits_override true
-
-
Announce on the feature issue 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 totrue
. -
Create a changelog entry.
-
-
Ensure that the default-enabling MR has been deployed to both production and canary. If the merge request was deployed before the code cutoff, the feature can be officially announced in a release blog post. -
/chatops run auto_deploy status <merge-commit-of-default-enabling-mr>
-
-
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 ci_runner_limits_override
". -
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.
-
Create a merge request to remove ci_runner_limits_override
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 deployed to both production and canary. If the merge request was deployed before the code cutoff, the feature can be officially announced in a release blog post. -
/chatops run auto_deploy status <merge-commit-of-cleanup-mr>
-
-
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 ci_runner_limits_override --dev
-
/chatops run feature delete ci_runner_limits_override --staging
-
/chatops run feature delete ci_runner_limits_override
-
-
Close this rollout issue.
Rollback Steps
-
This feature can be disabled by running the following Chatops command:
/chatops run feature set ci_runner_limits_override false