Pluggable online user counter, deployable straight on Heroku.

This is an entry for a CloudSpokes challenge.

• The counter only requires insertion of an iframe with a source URL containing the current username in the query
• Therefore no other backend modification is required, other than rendering the username into the iframe URL (backend notifying counter application would slow down response times, because of sync http notifications)
• Inside the iframe a socket.io connection is established with the counter server, which updates all clients in an async manner about joining or disconnecting users
• Clicking the counter text, a popup is opened with a full list of online members, their names used as links to their profiles

To use this online user counter on your website, follow these steps:

• Deploy the repository on heroku (see below, suppose your app address is http://xxx.herokuapp.com)
• Insert the following markup into your website (_USERNAME_ should be substituted by your logic to the logged in user's name)

<iframe style="width: 200px; height: 40px; border: 0;" src="http://xxx.herokuapp.com/embed?user=_USERNAME_"></iframe>

• Issue heroku apps:create [app-name] --stack cedar in a terminal, then clone the prompted git URL
• Copy content of this repository to the empty heroku repo
• git commit -a and git push origin master to push&deploy the repository on heroku

• Install necessary node.js libraries with npm install
• Launch the web server with node ./app.js

MIT license