Support for custom server directive using default_server broken by 9b4bb07

[Enchiridion]

I run several proxied sites simultaneously, to make it easier to see which sites are active I'm using docker-gen with a custom .tmpl file to auto-generate an html file, with links and tools for each site, whenever sites are started/stopped. I'm displaying the page at http://localhost/, to do so my custom nginx config takes over being the default server. I don't override /etc/nginx/conf.d/default.conf, I named mine so it loads first. My custom config is really small:

/etc/nginx/conf.d/01-custom.conf

server {
  server_name __; # This is just an invalid value which will never trigger on a real hostname.
  listen 80 default_server;
  access_log /var/log/nginx/access.log;
  root /app/web/public;
  index index.htm;
}

An update in commit 9b4bb07 broke it because it added default_server on lines 406, 408, 412, and 414. Nginx throws an error if there are multiple default servers for the same port.

From what I've read in the nginx docs, adding default_server is unnecessary in default.conf since the first server block becomes the default and default_server is only needed if you want to override that, which is what I need to do. I don't know enough about the codebase of nginx-proxy to know if removing those now would be ok or not, else I'd make a PR to remove them.

In the meantime, I've made a copy of nginx.tmpl, removed default_server, and replaced it in container using my Dockerfile, but it's not a long-term solution.

[buchdag]

@rhansen could you take a look at this ?

[buchdag]

@Enchiridion I suspect you're using a method to get a default virtual host that previously only worked "by accident".

The correct, tested method is using DEFAULT_HOST

[rhansen]

While users could just run a new container and point DEFAULT_HOST at it, it seems reasonable to me to support users that want a custom server directive, not a container, as the fallback handler. I'll open a PR with a fix and test coverage.

[Enchiridion]

Thanks for looking into and fixing it @buchdag and @rhansen !

[buchdag]

@Enchiridion could you try the fix proposed by @rhansen in #2214 and tell us if it works for you ?