Getting ready

To get started with debugging on the server side, you will need to have Node and Socket.IO installed and an existing app that uses Socket.IO. To test this out, you can easily use any of the apps we built in the previous recipes in this chapter.

How to do it…

To get server-side debugging turned on, follow these steps:

How it works…

Node.js environmental variables are available in process.env in any running Node process. They are often used to set up server-specific configurations, such as database connections and third-party credentials.

The great thing about using environmental variables to define the logging verbosity is that most cloud-based hosting providers allow you to change environmental variables on the fly, so you can easily toggle logging on or off without having to redeploy your code.

There's more…

Similar to client-side logging, you can set the logging type to something other than the wildcard. This allows you to only get debugging messages on the topic you want to listen to.

For example, listening for XHR requests is as simple as passing it to the environmental variables when you start your Node server with the following code:

DEBUG=socket.io:server node server