PoC: enable the metadata database for new installations

Context

As part of Release container registry with metadata databa... (&5521), we need to be able to enable the metadata database for new installations as stated in https://about.gitlab.com/install/. The two most common methods are either using Omnibus or Helm charts for Kubernetes deployments.

Problem

As of today, the metadata database is not enabled for new installations. However, with some tweaking it would be possible to enable the database and start using it for fresh installations.

Solution

The aim of this issue is to start experimenting and hacking with both of these installation methods to document what kind of changes are needed to be able to use the metadata database.

• PoC with a new omnibus installation
  • Snippet: https://gitlab.com/-/snippets/2572204
  • Video: https://youtu.be/_d27dDbLSv4
• PoC with a new Helm chart installation
  • Snippet: https://gitlab.com/-/snippets/2582598
  • Video: https://youtu.be/8rmLaVmFhzg