Websocket

The WebSocket Server is a lightweight and flexible server implementation that allows real-time communication between clients and servers using the WebSocket protocol. It provides a foundation for building WebSocket-based applications with ease and customization.

Valid WebSocket Connections

1. Authentication: The client must provide valid credentials and token during the WebSocket handshake. We will validate the credentials and token based on the headers, which includes the x-user-id, Sec-WebSocket-Protocol

   1. x-user-id: a type string, which is suppiled from Gateway or another service

   2. Sec-WebSocket-Protocol: a type string, which is given from the client

2. User: If we have two or more connections from the same user with the same x-user-id, only one will be approved. We have a boolean option variable KickOutNewUserConn to determine it.

WebSocket Message

• We only accept custom message, it be defined in ws.proto

Methods

• GetWsHandler: get websocket handler to registers a new route with a matcher

• SubscribeMessageHandler: function to subscribe a message handler when a message is sent from the client

• SubscribeDisconnectHandler: function to subscribe a disconnect handler when connection is closed

Examples

package ws

import (
    "flag"
    "log"
    "net/http"
    "testing"

    "gitlab.ugaming.io/marketplace/edk/pkg/ws"
)

var addr = flag.String("addr", ":8080", "http service address")

func main() {
    log.Println("start websocket service")
    client := New()

    http.HandleFunc("/ws", client.GetWsHandler())

    client.SubscribeMessageHandler(func(userID string, msg *ws.Message) {
        log.Printf("user %s: message: %s\n", userID, msg)
    })

    client.SubscribeDisconnectHandler(func(userID string) {
        log.Printf("user %s is disconnected\n", userID)
    })

    http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
        w.WriteHeader(200)
        w.Write([]byte("Hello world"))
    })

    err := http.ListenAndServe(*addr, nil)
    if err != nil {
        log.Printf("listen server error: %v\n", err)
    }
}