melody

:notes: Minimalist websocket framework for Go.

Melody is websocket framework based on github.com/gorilla/websocket that abstracts away the tedious parts of handling websockets. It gets out of your way so you can write real-time apps. Features include:

• Clear and easy interface similar to net/http or Gin.
• A simple way to broadcast to all or selected connected sessions.
• Message buffers making concurrent writing safe.
• Automatic handling of sending ping/pong heartbeats that timeout broken sessions.
• Store data on sessions.

Install

go get github.com/olahol/melody

Example: chat

package main

import (
	"net/http"

	"github.com/olahol/melody"
)

func main() {
	m := melody.New()

	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		http.ServeFile(w, r, "index.html")
	})

	http.HandleFunc("/ws", func(w http.ResponseWriter, r *http.Request) {
		m.HandleRequest(w, r)
	})

	m.HandleMessage(func(s *melody.Session, msg []byte) {
		m.Broadcast(msg)
	})

	http.ListenAndServe(":5000", nil)
}

Example: gophers

package main

import (
	"fmt"
	"net/http"
	"sync/atomic"

	"github.com/olahol/melody"
)

var idCounter atomic.Int64

func main() {
	m := melody.New()

	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		http.ServeFile(w, r, "index.html")
	})

	http.HandleFunc("/ws", func(w http.ResponseWriter, r *http.Request) {
		m.HandleRequest(w, r)
	})

	m.HandleConnect(func(s *melody.Session) {
		id := idCounter.Add(1)

		s.Set("id", id)

		s.Write([]byte(fmt.Sprintf("iam %d", id)))
	})

	m.HandleDisconnect(func(s *melody.Session) {
		if id, ok := s.Get("id"); ok {
			m.BroadcastOthers([]byte(fmt.Sprintf("dis %d", id)), s)
		}
	})

	m.HandleMessage(func(s *melody.Session, msg []byte) {
		if id, ok := s.Get("id"); ok {
			m.BroadcastOthers([]byte(fmt.Sprintf("set %d %s", id, msg)), s)
		}
	})

	http.ListenAndServe(":5000", nil)
}

More examples

Documentation

Contributors

FAQ

If you are getting a 403 when trying to connect to your websocket you can change allow all origin hosts:

m := melody.New()
m.Upgrader.CheckOrigin = func(r *http.Request) bool { return true }