[Feature flag] Rollout of `ci_workflow_rules_variables`

What

Remove the :ci_workflow_rules_variables feature flag ...

• Feature issue: #294232 (closed)
• Introduced in: !52085 (merged)
• Fixed in: !58777 (merged)

TODOs:

• Remove redundant methods to just control FF and return a value
• Remove redundant merge and just add value into the hash in lib/gitlab/web_ide/config/entry/terminal.rb

Owners

• Team: grouppipeline authoring
• Most appropriate slack channel to reach out to: #g_pipeline-authoring
• Best individual to reach out to: @furkanayhan

Expectations

What are we expecting to happen?

We are expecting that users can start using workflow:rules:variables.

What might happen if this goes wrong?

Pipelines may fail to start.

What can we monitor to detect problems with this?

• We should not see a decrease of 201 response code of Projects::PipelinesController#create endpoint: https://log.gprd.gitlab.net/goto/7d638af810e4b002de03d9df7132175c
• We should not see an increase of pipeline creation errors via PostReceive: https://log.gprd.gitlab.net/goto/1f47665f46009eab2b3e142a251ac17c
  • This metric is not enough itself because it is just a number. We should provide a metric like; errors / total number of enqueued workers PostReceive. Help?
  • For now; compare it with: https://log.gprd.gitlab.net/goto/542b35f80796baf5163d870af8796391

Beta groups/projects

If applicable, any groups/projects that are happy to have this feature turned on early. Some organizations may wish to test big changes they are interested in with a small subset of users ahead of time for example.

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

Roll Out Steps

• Enable on staging (/chatops run feature set ci_workflow_rules_variables true --staging)
• Test on staging
• Ensure that documentation has been updated
• Enable on GitLab.com for individual groups/projects listed above and verify behaviour (/chatops run feature set --project=gitlab-org/gitlab ci_workflow_rules_variables true)
• Coordinate a time to enable the flag with the SRE oncall and release managers
  • In #production mention @sre-oncall and @release-managers. Once an SRE on call and Release Manager on call confirm, you can proceed with the rollout
• Announce on the issue an estimated time this will be enabled on GitLab.com
• Enable on GitLab.com by running chatops command in #production (/chatops run feature set ci_workflow_rules_variables true)
• Cross post chatops Slack command to #support_gitlab-com (more guidance when this is necessary in the dev docs) and in your team channel
• Announce on the issue that the flag has been enabled
• Remove feature flag and add changelog entry
• After the flag removal is deployed, clean up the feature flag by running chatops command in #production channel

Rollback Steps

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

/chatops run feature set --project=gitlab-org/gitlab ci_workflow_rules_variables false