[Feature Flag] Rollout visualization tab in PA home

What

Activate the :ci_config_visualization_tab feature flag progressively and remove it all together once it has been proven to work

Remove the :ci_config_visualization_tab feature flag ...

Owners

• Team: Pipeline Authoring
• Most appropriate slack channel to reach out to: #g_pipeline-authoring
• Best individual to reach out to: Frédéric Caplette (@f_caplette)

Expectations

What are we expecting to happen?

The new tab will render a graphical visualization of CI config jobs and needs

What might happen if this goes wrong?

The graph will not render for certain users. This should be contained within the tab, but to make sure it doesn't have a bad effect on the rest of the new Authoring section, we are being extra careful.

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-ui project

Roll Out Steps

• Confirm that QA tests pass with the feature flag enabled (if you're unsure how, contact the relevant stable counterpart in the Quality department)
• Enable on staging (/chatops run feature set feature_name 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 feature_name 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 feature_name 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 feature_name false