Socket.io failed: WebSocket is closed before the connection is established

Question

The Issue

My Twitter streaming app using Socket.io works okay when visiting the site with the IP address and port, but live streaming throws an error, when using the d

Answer 1

Found the solution, and it was in fact simple! Posting the answer here, to help others facing a similar issue, because I was totally stuck on this for 2 days!

My issue was caused by a dependency update.

Socket.io V 2.0.0 is not backward compatible.

According to the release notes:

The new (V 2.0.0) major release brings several performance improvements, but also snuck into the bottom of the release notes was this:

This release is not backward-compatible, due to:

• A breaking change related to utf-8 encoding in engine.io-parser (socketio/engine.io-parser#81)
• an update to make the socket id on the client match the id on the server-side (socketio/socket.io-client#1058)

Please note that if you are using a self-signed certificate, rejectUnauthorized now defaults to true (socketio/engine.io-client#558).

Here's the full V2 release notes: https://github.com/socketio/socket.io/releases/tag/2.0.0

The solution is to use HTTPS

Make your app https, or sign your own requests, as per documentation. As a quick fix though, I just downgraded back to socket.io V 1.7.0 and it works perfectly