Merge pull request #43 from KarmaComputing/41-as-developer-I-can-use-…

…custom-port

Fix #41 document how to change the application port listened on using EXPOSE

repo-template-files/README.md

@@ -79,3 +79,4 @@ Ta-da! You'll be inside the [Python debugger](https://docs.python.org/3/library/
 ## Questions
 
 - How was this built? [All code is here](https://github.com/KarmaComputing/container-hosting)
+- How can I use a customized port numberi/change the port number listened on? You don't need to do this if you use the quickstarts. But if you do want to alter the port: Edit your `Dockerfile` and change `EXPOSE` to the port number you want your app to listen on. Understand that all apps go through the proxy (nginx) listening on port `80` and `443`, requests to your app get proxied (based on your hostname) to the port number you put after `EXPOSE` in your your `Dockerfile`. For example `EXPOSE 3000` means you want the Dokku nginx proxy to forward port `80` and `443` connections to port `3000`. You still need to make your application listen on your chosen port.