Display a list of discovered virtual hosts

Procfile

@@ -1,2 +1,3 @@
 nginx: nginx
 dockergen: docker-gen -watch -only-exposed -notify "nginx -s reload" /app/nginx.tmpl /etc/nginx/conf.d/default.conf
+dockergen: docker-gen -watch -only-exposed /app/index.html.tmpl /app/www/index.html

index.html.tmpl

@@ -0,0 +1,13 @@
+<h1>Nginx Reverse Proxy for Docker</h1>
+
+{{ with groupByMulti $ "Env.VIRTUAL_HOST" "," }}
+<ul>
+	{{ range $host, $containers := . }}
+		<li><a href="http://{{ $host }}">{{ (first $containers).Name }}</a></li>
+	{{ end }}
+</ul>
+{{ else }}
+	<p>The Nginx Reverse Proxy for Docker is started but no virtual hosts have been found. Try starting one with the <em>VIRTUAL_HOST</em> environement variable set.</p>
+	<pre>$ docker run --rm --name helloworld --expose 8080 -e VIRTUAL_HOST=helloworld.127.0.0.1.xip.io adejonge/helloworld</pre>
+	<p><a href="https://github.com/jwilder/nginx-proxy#usage">More information on Github</a></p>
+{{ end }}

nginx.tmpl

@@ -34,7 +34,10 @@ proxy_set_header X-Forwarded-Proto $proxy_x_forwarded_proto;
 server {
 	listen 80 default_server;
 	server_name _; # This is just an invalid value which will never trigger on a real hostname.
-	return 503;
+	location / {
+		root /app/www/;
+	}
+	error_page 404 /;
 }
 
 {{ range $host, $containers := groupByMulti $ "Env.VIRTUAL_HOST" "," }}

www/index.html

@@ -0,0 +1,6 @@
+<h1>Nginx Reverse Proxy for Docker</h1>
+
+<p>
+	The Nginx Reverse Proxy for Docker has not yet started.
+	<a href="https://github.com/jwilder/nginx-proxy#usage">More information on Github</a>
+</p>