websocket

Okapi WebSocket (okapiws)

WebSocket support ships as a separate, framework-agnostic package. It works with Okapi handlers and with plain net/http.

Installation

The repository is jkaninda/okapi-ws, but the module path is github.com/jkaninda/okapiws — use that in go get and in imports:

go get github.com/jkaninda/okapiws

import okapiws "github.com/jkaninda/okapiws"

Built on github.com/gorilla/websocket.

Upgrading Inside an Okapi Handler

c.Response() implements Hijack, so the upgrader works directly:

func WebSocket(config *okapiws.WSConfig, c *okapi.Context) (*okapiws.WSConnection, error) {
    upgrader := okapiws.NewWSUpgrader(config) // nil config = defaults
    return upgrader.Upgrade(c.Response(), c.Request(), nil)
}

func WebSocketWithHeaders(config *okapiws.WSConfig, headers http.Header, c *okapi.Context) (*okapiws.WSConnection, error) {
    upgrader := okapiws.NewWSUpgrader(config)
    return upgrader.Upgrade(c.Response(), c.Request(), headers)
}

Or upgrade with defaults in one call: okapiws.Default(c.Response(), c.Request(), nil).

Echo Server

func main() {
    app := okapi.Default()

    app.Get("/", func(c *okapi.Context) error {
        return c.OK(okapi.M{"message": "Hello from Okapi!"})
    })

    app.Get("/ws", handleWebSocket)

    if err := app.Start(); err != nil {
        panic(err)
    }
}

func handleWebSocket(c *okapi.Context) error {
    ws, err := WebSocket(nil, c)
    if err != nil {
        return err
    }
    defer func() {
        if err := ws.Close(); err != nil {
            log.Printf("error closing WebSocket: %v", err)
        }
    }()

    ws.OnMessage(func(msg *okapiws.WSMessage) {
        log.Printf("[%d] %s", msg.Type, msg.Data)
        _ = ws.Send(msg.Data) // echo back
    })

    ws.OnError(func(err error) { log.Printf("WebSocket error: %v", err) })
    ws.OnClose(func() { log.Println("client disconnected") })

    ws.Start()            // start the read/write pumps

    <-ws.Context().Done() // block until the connection closes
    return nil
}