Example of how one might do websocket logging when using go-apachelog for http logging.

wslog.go

package main

import (
	"io"
	"log"
	"net/http"
	"os"
	"time"

	"code.google.com/p/go.net/websocket"
	apachelog "github.com/cespare/go-apachelog"
)

const addr = "localhost:8888"

// Where to write all the logs.
var out = os.Stderr

func init() { log.SetOutput(out) }

type wsHandlerFunc func(io.Writer, []byte) error

func EchoHandler(w io.Writer, msg []byte) error {
	_, err := w.Write(msg)
	return err
}

func wsLog(ws *websocket.Conn, format string, args ...interface{}) {
	args = append([]interface{}{ws.RemoteAddr()}, args...)
	log.Printf("[websocket] (%s) "+format, args...)
}

func MakeWSHandler(handleFunc wsHandlerFunc) websocket.Handler {
	return func(ws *websocket.Conn) {
		wsLog(ws, "connection opened")
		totalStart := time.Now()
		var totalBytes uint64
		buf := make([]byte, 1024)
		for {
			// TODO: handle frames larger than buf as a single message and call to handleFunc
			n, err := ws.Read(buf)
			if err != nil {
				if err == io.EOF {
					break
				} else {
					wsLog(ws, "error: %s", err)
					return
				}
			}
			start := time.Now()
			if err := handleFunc(ws, buf); err != nil {
				wsLog(ws, "error: %s", err)
				return
			}
			elapsed := time.Since(start)
			wsLog(ws, "message %d %.4f", n, elapsed.Seconds())
			totalBytes += uint64(n)
		}
		totalElapsed := time.Since(totalStart)
		wsLog(ws, "connection closed %d %.4f", totalBytes, totalElapsed.Seconds())
	}
}

func Handle(w http.ResponseWriter, r *http.Request) {
	w.Write([]byte("hello"))
}

func main() {
	mux := http.NewServeMux()
	mux.Handle("/ws", MakeWSHandler(EchoHandler))
	mux.HandleFunc("/a", Handle)
	logger := apachelog.NewHandler(mux, out)
	server := &http.Server{
		Handler: logger,
		Addr:    addr,
	}
	log.Fatal(server.ListenAndServe())
}