Group hooks (custom hooks per group basis)

Description

As I understand the documentation, there is no simple way to define custom serverside hooks on group level. At the moment there are global hooks and per project hooks.

Proposal

Something between project custom hooks and globally defined hooks.

Links / references

https://docs.gitlab.com/ce/administration/custom_hooks.html

Overview

In a group of projects similar behaviour is neccessary. Defining it globally is here not applicable.

Use cases

We want to create a group of projects with identical hooks. Adding a new project to this groups creates workload/overhead by adding the same custom hooks at the server.

...but maybe it's allready available or possible today?