melody

:notes: Minimalist websocket framework for Go

Description

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:

Programming language: Go

License: BSD 2-clause "Simplified" License

Tags: Web Frameworks     Websocket    

README

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:

• [x] Clear and easy interface similar to net/http or Gin.
• [x] A simple way to broadcast to all or selected connected sessions.
• [x] Message buffers making concurrent writing safe.
• [x] Automatic handling of ping/pong and session timeouts.
• [x] Store data on sessions.

Install

go get gopkg.in/olahol/melody.v1

Example: chat

Using Gin:

package main

import (
    "github.com/gin-gonic/gin"
    "gopkg.in/olahol/melody.v1"
    "net/http"
)

func main() {
    r := gin.Default()
    m := melody.New()

    r.GET("/", func(c *gin.Context) {
        http.ServeFile(c.Writer, c.Request, "index.html")
    })

    r.GET("/ws", func(c *gin.Context) {
        m.HandleRequest(c.Writer, c.Request)
    })

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

    r.Run(":5000")
}

Using Echo:

package main

import (
    "github.com/labstack/echo"
    "github.com/labstack/echo/engine/standard"
    "github.com/labstack/echo/middleware"
    "gopkg.in/olahol/melody.v1"
    "net/http"
)

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

    e.Use(middleware.Logger())
    e.Use(middleware.Recover())

    e.GET("/", func(c echo.Context) error {
        http.ServeFile(c.Response().(*standard.Response).ResponseWriter, c.Request().(*standard.Request).Request, "index.html")
        return nil
    })

    e.GET("/ws", func(c echo.Context) error {
        m.HandleRequest(c.Response().(*standard.Response).ResponseWriter, c.Request().(*standard.Request).Request)
        return nil
    })

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

    e.Run(standard.New(":5000"))
}

Example: gophers

package main

import (
    "github.com/gin-gonic/gin"
    "gopkg.in/olahol/melody.v1"
    "net/http"
    "strconv"
    "strings"
    "sync"
)

type GopherInfo struct {
    ID, X, Y string
}

func main() {
    router := gin.Default()
    mrouter := melody.New()
    gophers := make(map[*melody.Session]*GopherInfo)
    lock := new(sync.Mutex)
    counter := 0

    router.GET("/", func(c *gin.Context) {
        http.ServeFile(c.Writer, c.Request, "index.html")
    })

    router.GET("/ws", func(c *gin.Context) {
        mrouter.HandleRequest(c.Writer, c.Request)
    })

    mrouter.HandleConnect(func(s *melody.Session) {
        lock.Lock()
        for _, info := range gophers {
            s.Write([]byte("set " + info.ID + " " + info.X + " " + info.Y))
        }
        gophers[s] = &GopherInfo{strconv.Itoa(counter), "0", "0"}
        s.Write([]byte("iam " + gophers[s].ID))
        counter += 1
        lock.Unlock()
    })

    mrouter.HandleDisconnect(func(s *melody.Session) {
        lock.Lock()
        mrouter.BroadcastOthers([]byte("dis "+gophers[s].ID), s)
        delete(gophers, s)
        lock.Unlock()
    })

    mrouter.HandleMessage(func(s *melody.Session, msg []byte) {
        p := strings.Split(string(msg), " ")
        lock.Lock()
        info := gophers[s]
        if len(p) == 2 {
            info.X = p[0]
            info.Y = p[1]
            mrouter.BroadcastOthers([]byte("set "+info.ID+" "+info.X+" "+info.Y), s)
        }
        lock.Unlock()
    })

    router.Run(":5000")
}

More examples

Documentation

Contributors

• Ola Holmström (@olahol)
• Shogo Iwano (@shiwano)
• Matt Caldwell (@mattcaldwell)
• Heikki Uljas (@huljas)
• Robbie Trencheny (@robbiet480)
• yangjinecho (@yangjinecho)

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 }