Move Prometheus Integration to Operations Settings

Proposal

• Add a Prometheus section in Settings > Operations.
• Convert the existing Prometheus integration screen into a placeholder, which directs users to the new location.
• As mentioned in #24651 (comment 346122485) - the alerts section of the Prometheus configuration can be removed as soon as we complete #218572 (closed) so it doesn't need to be moved as part of this effort. Only the Auto Configuration, Manual Configuration and Metrics need to be moved to Settings > Operations.

Design

The screen on the left would be the new settings > operations page, and the screen on the right is the current settings > integrations > prometheus page after the switch. Post-switch, the current page would have all the buttons disabled, and would have an alert linking to the new settings > operations page.

New settings page	Old integrations page

Next Steps

• In a separate iteration we'll need to update the design of the Prometheus section following this design proposal.
• We also want to explore better long-term solutions to the placement of Prometheus configuration, to bring it closer to the Operations tools themselves

Implementation

• Add feature flag

Features to move

• user can add manual configuration for Promethues

• user can update manual configuration for Promethues

• user can delete manual configuration for Promethues

• user can add custom metric

• existing custom metrics are detected

• user can edit custom metric

• user can delete custom metric

• existing common metrics are detected

• integration status is detected

• not active service integrations displays link to install prometheus on a cluster

• Promethes from gitlab-managed-apps display links to manage cluster

• Promethes from gitlab-managed-apps disables manual configuration of service

• For manually configured services cluster management is hidden

• For manually configured services alerts config can be added

• For manually configured services alerts config can be updated

• New metric panel display correct breadcrumbs

• Edit metric panel display correct breadcrumbs

• After manual configuration is saved user is redirected to operations section

• After manual configuration changes are canceled (Cancel button) user is redirected to operations section

• After new metrics is added user is redirected to operations section

• After new metrics form is closed (Cancel button) user is redirected to operations section

• After existing metrics is updated user is redirected to operations section

• After existing metrics is deleted user is redirected to operations section

• After existing metrics edict from is closed (Cancel button) user is redirected to operations section

Backend

• add prometheus service variable to operations OperationsController#show