nginx.conf

map $http_host $subdomain_port {
  hostnames;

  www.donmccurdy.com            8001;
  sandbox.donmccurdy.com        8002;
  proxy-controls.donmccurdy.com 8003;
}

server {
  server_name         _;
  return              301 https://$host$request_uri;
}

server {
  listen              443 ssl;
  server_name         donmccurdy.com;
  root                /home/donmccurdy/public;

  access_log          /var/log/nginx/donmccurdy.log;
  error_log           /var/log/nginx/donmccurdy.error.log;

  ssl_certificate     <cert>;
  ssl_certificate_key <key>;

  if ($subdomain_port = "") {
    return            302 https://www.donmccurdy.com$request_uri;
  }

  location / {
    try_files         $uri @proxy;
  }

  location @proxy {
    proxy_http_version 1.1;
    proxy_set_header  Upgrade $http_upgrade;
    proxy_set_header  Connection "upgrade";
    proxy_set_header  X-Real-IP $remote_addr;
    proxy_set_header  X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header  X-Forwarded-Proto https;
    proxy_set_header  Host $http_host;
    proxy_set_header  X-NginX-Proxy true;

    proxy_pass        http://127.0.0.1:$subdomain_port;
    proxy_redirect    off;
  }
}