wskit

go-wskit

WebSocket hub-and-spoke server on coder/websocket with optional Redis Pub/Sub for multi-instance broadcast.

Install

go get github.com/wahrwelt-kit/go-wskit

import "github.com/wahrwelt-kit/go-wskit"

Features

• Hub - single-goroutine dispatcher with register/unregister/broadcast channels, graceful shutdown via context, atomic subscriber count
• Client - ReadPump (drain incoming) + WritePump (send + ping/pong), safe concurrent Send with close protection
• SSEClient - Server-Sent Events subscriber; AcceptSSE registers it with the hub and streams data until disconnect or shutdown
• Redis Pub/Sub - BroadcastEvent with JSON serialization, fallback to local broadcast on Redis failure, SubscribeToRedis for horizontal scaling
• Event envelope - Event{Type, Payload, Timestamp} standard JSON format, BroadcastJSON helper
• Accept / AcceptSSE helpers - upgrade HTTP to WebSocket or SSE + create client + register in one call
• Functional options - configurable timeouts, buffer sizes, callbacks

Example

hub := wskit.NewHub(
    wskit.WithRedis(redisClient, "ws:events"),
    wskit.WithOnConnect(func(sub wskit.Subscriber) {
        data, _ := json.Marshal(wskit.NewEvent("connected", nil))
        sub.Send(data)
    }),
)
go hub.Run(ctx)
go hub.SubscribeToRedis(ctx)

// WebSocket endpoint
http.HandleFunc("/ws", func(w http.ResponseWriter, r *http.Request) {
    client, err := wskit.Accept(r.Context(), w, r, hub, nil)
    if err != nil {
        return
    }
    go client.ReadPump()
    go client.WritePump()
})

// SSE endpoint
http.HandleFunc("/events", func(w http.ResponseWriter, r *http.Request) {
    wskit.AcceptSSE(w, r, hub)
})

hub.BroadcastJSON(ctx, "notification", map[string]string{"message": "hello"})

Options

Hub: WithRedis, WithBroadcastBuf, WithRegisterBuf, WithChannelTimeout, WithOnTimeout, WithOnConnect, WithOnDisconnect

Client: WithWriteWait, WithPingInterval, WithMaxMessageSize, WithSendBufSize