[Feature flag] Enable `web_hooks_disable_failed`

Feature

This feature uses the :web_hooks_disable_failed feature flag!

This feature enables us to detect repeated failures and pro-actively disable failing web-hooks.

• See: https://gitlab.com/gitlab-org/gitlab/-/issues/329213

We do not expect this to be enabled until UI elements are in place.

Owners

• Team: ~"group::integrations"
• Most appropriate slack channel to reach out to: #g_ecosystem_be
• Best individual to reach out to: @alexkalderimis
• PM: @g.hickman
• EM: @arturoherrero

The Rollout Plan

• Partial Rollout on GitLab.com with beta groups

Beta Groups/Projects:

• gitlab-org/gitlab project
• gitlab-org/gitlab-com groups

Expectations

What are we expecting to happen?

We expect that webhooks that fail will be disabled. Ones that fail with 5xx errors will come back after a cooldown period and users will notice little disruption. Ones that fail with 4xx errors will be disabled and will need to be re-enabled. There may be users who are unhappy about this.

What might happen if this goes wrong?

Users workflows could break, webhooks could get disabled and they might not know what to do.

In the worst case, they won't be able to re-enable them, even when the webhook server is working.

If there are any problems we should disable this feature flag, which will re-enable all webhooks.

Feature.disable(:web_hooks_disable_failed)

What can we monitor to detect problems with this?

We should monitor the Projects::HooksController and TestHooks::ProjectService. Failures to re-enable hooks will be seen here as errors. Sentry should help here.

Rollout Steps

Rollout on non-production environments

Initial Rollout

Preparation Phase

• Enable on staging (/chatops run feature set web_hooks_disable_failed true --staging)

• Test on staging

• Ensure that documentation has been updated (More info)

• Announce on the issue an estimated time this will be enabled on GitLab.com

• Check if the feature flag change needs to be accompagnied with a change management issue. Cross link the issue here if it does.

• 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 web_hooks_disable_failed true --dev
  • /chatops run feature set web_hooks_disable_failed true --staging

• Verify that the feature works as expected. Posting the QA result in this issue is preferable.

Specific rollout on production

• Ensure that the feature MRs have been deployed to both production and canary.
  • /chatops run auto_deploy status <merge-commit-of-your-feature>
• If you're using project-actor, you must enable the feature on these entries:
  • /chatops run feature set --project=gitlab-org/gitlab web_hooks_disable_failed true
  • /chatops run feature set --project=gitlab-org/gitlab-foss web_hooks_disable_failed true
  • /chatops run feature set --project=gitlab-com/www-gitlab-com web_hooks_disable_failed true
• If you're using group-actor, you must enable the feature on these entries:
  • /chatops run feature set --group=gitlab-org web_hooks_disable_failed true
  • /chatops run feature set --group=gitlab-com web_hooks_disable_failed true
• Verify that the feature works on the specific entries. Posting the QA result in this issue is preferable.

Preparation before global rollout

• Check if the feature flag change needs to be accompanied with a change management issue. See: gitlab-com/gl-infra/production#6448 (closed)
• 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.
• Notify #support_gitlab-com and your team channel (more guidance when this is necessary in the dev docs).

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.
  • If the feature flag in code has an actor, perform actor-based rollout.
    • /chatops run feature set web_hooks_disable_failed <rollout-percentage> --actors
  • If the feature flag in code does NOT have an actor, perform time-based rollout (random rollout).
    • /chatops run feature set web_hooks_disable_failed <rollout-percentage>
  • Enable the feature globally on production environment.
    • Important: First ensure previously affected customer's hooks are made exempt #329849 (comment 1109721299).
    • /chatops run feature set web_hooks_disable_failed 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 to true.
  • 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 web_hooks_disable_failed".
  • 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 web_hooks_disable_failed 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 77adcd5a0768381d398ae96ac05bb58cf4465e9a
• 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 web_hooks_disable_failed --dev
  • /chatops run feature delete web_hooks_disable_failed --staging
  • /chatops run feature delete web_hooks_disable_failed
• Close this rollout issue.

Rollback Steps

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

/chatops run feature set web_hooks_disable_failed false