503 for default or non-existent virtual hosts

[mcnesium]

There should be a 503 or something, if a request comes in on a domain or IP address that is not defined by VIRTUAL_HOST env var. Instead, it just redirects to the first defined one.

According to this there must be a default added to the default listen-directive, for which I assume here is the right place. This file gets re-generated each time the proxy container starts though.

Is this within the scope of this project or rather upstream at jwilder/nginx-proxy?

[buchdag]

According to the answer from server fault that you quoted:

If you omit the default parameter, the first server block is treated as the default.

So this server block is already the default, being always the first.

I think your issue is instead yet another duplicate of #74, #373 and #411

If it is, could you close this issue and continue the discussion on #411 ?

[mcnesium]

Looks like it. My experience with nginx is very little, I can only compare it to Apache's 000-default.conf that prevents requests to arbitrary domains/IP-addresses to reach a wrong web service.