nginx config for proxying requests for plex over a hostname-based virtualhost.

nginx.conf

upstream plex-upstream {
	# change plex-server.example.com:32400 to the hostname:port of your plex server.
	# this can be "localhost:32400", for instance, if Plex is running on the same server as nginx.
	server plex-server.example.com:32400;
}

server {
	listen 80;

	# server names for this server.
	# any requests that come in that match any these names will use the proxy.
	server_name
		tv
		plex
		tv.example.com
		plex.example.com;

	# this is where everything cool happens (you probably don't need to change anything here):
	location / {
		# if a request to / comes in, 301 redirect to the main plex page.
                # but only if it doesn't contain the X-Plex-Device-Name header
		# this fixes a bug where you get permission issues when accessing the web dashboard
		if ($http_x_plex_device_name = '') {
			rewrite ^/$ http://$http_host/web/index.html;
		}

		# set some headers and proxy stuff.
		proxy_set_header X-Real-IP $remote_addr;
		proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
		proxy_redirect off;

		# include Host header
		proxy_set_header Host $http_host;

		# proxy request to plex server
		proxy_pass http://plex-upstream;
	}
}

thanks

Did you ever get it working @andrewm659 ?

Update: The original gist without the proxy_set_headers as mentioned in follow-ups works well.
Thanks @spikegrobstein.