Add feature flag to block top-level group creation via api [RUN ALL RSPEC] [RUN AS-IF-FOSS]

Merged Gosia Ksionek requested to merge 323573-limit-creating-top-level-groups into master

What does this MR do?

In this MR I created new policy, checked only during group creation via API - it blocks user from creating top-level group if:

  • we're on
  • feature flag allowing to create top-level group is disabled

Does this MR meet the acceptance criteria?


Availability and Testing


If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

  • Label as security and @ mention @gitlab-com/gl-security/appsec
  • The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
  • Security reports checked/validated by a reviewer from the AppSec team

Related to #323573

Edited by Gosia Ksionek