Hey!
Thanks for this project, very useful - I'll be moving over from Kopf soon.

I'm currently setting up preview environment for my PRs, where each environment has it's own copy of elasticsearch etc. I'm currently getting some port clashes with the other services within my stack.

I see on the Cerebro config you can specify something like http.port=1234 to change the exposed port.

I'm wondering if it would be possible to update the Dockerfile to allow us to set the port as an environment variable? I can have a go raising a PR some point soon, just wondered if anything was in the works?