nginxreverseauth

This small webserver can be used with the nginx http_auth_request_module.

It will do a lookup of the domain in dynamic_domains and checks the ip of the requesting client matches the domain ip and returns a http 200 if both matches. This way you can use the module with dynamic ips that have dynamic dns entries. DNS results are currently cached for one hour.

Example nginx config to use with this:

location /private/ {
    auth_request /auth;
    ...
}

location = /auth {
  allow 127.0.0.0/8;
  allow 10.0.0.0/8;
  allow 172.16.0.0/12;
  allow 192.168.0.0/16;
  deny all;

  proxy_pass_request_body off;
  proxy_set_header Content-Length "";
  proxy_set_header X-Original-URI $request_uri;
  proxy_set_header X-Real-IP $remote_addr;
  proxy_pass http://localhost:8081;
}

To make this work you need to build the binary yourself or download it from the release section.

You need a config file containing all your dynamic dns records that you would like to allow. Just copy config.sample.json and edit it to your needs.

Config Options

You can either set the options via command line parameters, environment variables or create a .env file containing the environment variable names. When you use .env the environment variables will be populated with the values.

Commandline parameter	env variable/.env entry	default	description
-host	NGINX_HOST	127.0.0.1:8080	IP and Port to bind to
-debug	NGINX_DEBUG	false	enable debug output
-graceful-timeout	NGINX_GRACEFUL_TIMEOUT	2s	the duration for which the server waits on exit for existing connections to finish
-timeout	NGINX_TIMEOUT	5s	dns and http timeout
-config	NGINX_CONFIG	config.json	config file to use