How to Identify Users in a Ktor WebSocket Server?

Question

I'm working on a Ktor application with WebSockets and I want to understand how to identify connected users. Specifically, I'm interested in knowing:

• User Information: Is it possible to access user information like IP address or session data within the WebSocket handler?
• Alternatives: If direct access isn't possible, are there alternative approaches to differentiate between connected users within the handler?

Code Snippet:

fun Application.configureSockets() {
    install(WebSockets) {
        // some configuration
    }
    routing("/ws") {
        for (frame in incoming) {
            // some code
        }
    }
}

• I'm open to learning about any best practices or security considerations regarding user identification in Ktor WebSockets.

Answer 1

You can get information about the WebSocket request, including the information about the client address, by calling the call.request within the WebSocket handler. Here is how you can get the client's remote IP address:

routing {
   webSocket("/ws") {
       val ip = call.request.local.remoteAddress
   }
}