.localhost Domains

This nginx local dev config snippet is one-and-done:

  # Proxy to a backend server based on the hostname.
  if (-d vhosts/$host) {
    proxy_pass http://unix:vhosts/$host/server.sock;
    break;
  }

Your local dev servers must listen on a unix domain socket, and you must drop a symlink to them at eg /var/lib/nginx/vhosts/inclouds.localhost/server.sock.

Not a single command, and you still have to add hostname resolution. But you don't have to programmatically edit config files or restart the proxy to stand up a new dev server!

This is neat!

I'm not that familiar with nginx config. Does this protect against path traversal? Ex: host=../../../docker.sock

nginx validates hostnames per the spec, and to your question specifically it rejects requests that would put a slash in $host: https://github.com/nginx/nginx/blob/b6e7eb0f5792d7a52d2675ee...