This is a Heroku Buildpack for running a auxiliary port on a process in dyno. The auxiliary port will be proxied by ngrok, which makes it accessible from a remote machine. By default, the port is 9090, but it can be configured with the $AUX_PORT config variable.

First, create a free ngrok account. This is necessary to use TCP with their service. Then capture your API key, and set it as a config var on your Heroku app like this:

$ heroku config:set NGROK_API_TOKEN=xxxxxx

Next, add this buildpack to your app:

$ heroku buildpacks:add jkutner/ngrok

Then add your primary buildpack. For example, if you are using Java:

$ heroku buildpacks:add heroku/java

Now modify your Procfile by prefixing your web process with the with_ngrok command. For example:

web: with_ngrok java $JAVA_OPTS -cp target/classes:target/dependency/* Main

Finally, commit your changes, and redeploy the app:

$ git add Procfile
$ git commit -m "Added with_ngrok"
$ git push heroku master

Once your app is running with the ngrok buildpack and the with_ngrok command, you'll see something like this in your logs:

2015-05-19T16:06:36.530988+00:00 app[web.1]: Listening for transport dt_socket at address: 8998
...
2015-05-19T16:06:37.052977+00:00 app[web.1]: [05/19/15 16:06:37] [INFO] [client] Tunnel established at tcp://ngrok.com:39678

Then, from your local machine, you can connect to the auxiliary port using the ngrok URL in the logs. For example:

$ open http://ngrok.com:39678

You can customize the aux port like so:

$ heroku config:set AUX_PORT=5001

You can customize the execution of ngrok by setting the NGROK_OPTS config var like so:

$ heroku config:set NGROK_OPTS="-subdomain=my-custom-name"

You can also add a .ngrok to your app.