Configure http server to only listen on known vhosts/IP

For the rest it returns 404

Fixes #446

setup/start/nginx/appconfig.ejs

@@ -4,6 +4,41 @@ map $http_upgrade $connection_upgrade {
     '' close;
 }
 
+# http server
+server {
+    listen       80;
+<% if (hasIPv6) { -%>
+    listen       [::]:80;
+<% } -%>
+
+<% if (vhost) { -%>
+    server_name  <%= vhost %>;
+<% } else { -%>
+    # IP based access. TODO: match the IPv6 address
+    server_name  "~^\d+\.\d+\.\d+\.\d+$";
+
+    # collectd
+    location /nginx_status {
+        stub_status on;
+        access_log off;
+        allow 127.0.0.1;
+        deny all;
+    }
+
+    # acme challenges
+    location /.well-known/acme-challenge/ {
+        default_type text/plain;
+        alias /home/yellowtent/platformdata/acme/;
+    }
+<% } -%>
+
+    location / {
+        # redirect everything to HTTPS
+        return 301 https://$host$request_uri;
+    }
+}
+
+# https server
 server {
 <% if (vhost) { -%>
     server_name  <%= vhost %>;