[Storage] [Feature flag] Remove the 'new_route_storage_purchase' feature flag

In order to rollout feature flag :new_route_storage_purchase and release the feature CI Minutes, we proceed as follow:

roll-out :new_route_storage_purchase	#327896 (closed)
release the feature and remove :new_route_storage_purchase	👈 you are here

Summary

This issue is to roll out the feature on production, that is currently behind the <new_route_storage_purchase> feature flag.

The feature is updating the Storage purchase from an external one (on Customers Portal) to the one embedded in GitLab. More details in the Epic.

Owners

• Team: grouppurchase [DEPRECATED]
• Most appropriate slack channel to reach out to: #g_purchase
• Best individual to reach out to: @agulina
• PM: @tgolubeva

Stakeholders

The Rollout Plan

• Partial Rollout on GitLab.com with testing groups
• Rollout on GitLab.com for a certain period (2 milestones)
• Percentage Rollout on GitLab.com
• Rollout Feature for everyone as soon as it's ready

Testing Groups/Projects/Users

Expectations

What are we expecting to happen?

When a group is eligible for purchasing additional Storage...

What might happen if this goes wrong?

If something goes wrong, the customers won't be able to purchase additional Storage. Disabling the FF will be sufficient to solve any incident.

What can we monitor to detect problems with this?

Rollout Steps

The rollout part is handled with #327896 (closed)

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 <feature-flag-name> 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 <feature-flag-name> --dev NOT RELEVANT
  • /chatops run feature delete new_route_storage_purchase --staging
  • /chatops run feature delete new_route_storage_purchase
• Close this rollout issue.

Rollback Steps

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

/chatops run feature set new_route_storage_purchase false