gitlab docker registry with external nginx and omnibus returns 502

I already run an gitlab server inside an docker container with an external nginx server inside an other, so the gitlab nginx server is deactivated. Now I want to use the docker registry included in the gitlab server.

I try to get the information from the administration manual: https://docs.gitlab.com/ee/administration/container_registry.html

and use fitted nginx config from linked file: https://gitlab.com/gitlab-org/gitlab-ce/blob/master/lib/support/nginx/registry-ssl (works with an other docker registry container)

to the gitlab.rb I added:

... registry_external_url 'url' registry_nginx['enable'] = false registry['enable'] = true ...

But if I try to login (docker login url) but I only get an 502 Bad Gateway error. I also tried some other configuration combinations, but getting always got the same error. Do anybody get it work? Need I to add more settings to the omnibus file or is it still not possible to use the gitlab internal docker registry with omnibus and external nginx?