gqtt

MQTT5 broker/client implementation by golang.

See OASIS’s spec: http://docs.oasis-open.org/mqtt/mqtt/v5.0/cs02/mqtt-v5.0-cs02.html

Requirement

• Go1.12 or later

Installation

This packages uses go mod, so you need to enable it as export GO111MODULE=on in your environment.

Usage

To debug message passing, set export DEBUG=1 before start processes.

Broker

Simple broker with accept hook message example:

package main
import (
    "context"
    "github.com/ysugimoto/gqtt"
    "github.com/ysugimoto/gqtt/message"
)
func main() {
    server := gqtt.NewBroker(":9999")
    ctx := context.Background()
    // Start server inside goroutine
    go server.ListenAndServe(ctx)
    // Hooks of messages
    for evt := range server.MessageEvent {
        switch e := evt.(type) {
        // Client subscribed
        case *message.Subscribe:
            log.Println("Received SUBSCRIBE event: ", e.GetType())
        // Client connected
        case *message.Connect:
            log.Println("Received CONNECT event", e.GetType())
        // Client published message
        case *message.Publish:
            log.Println("Received PUBLISH event", e.GetType())
        }
    }
    <-ctx.Done()
}

Client

Simple connect (with authentication) -> subscribe -> publish example.
The auth challenge during connect phase is new of MQTT5 spec.

package main
import (
    "log"
    "os"
    "time"
    "context"
    "github.com/ysugimoto/gqtt"
    "github.com/ysugimoto/gqtt/message"
)
func main() {
    client := gqtt.NewClient("mqtt://localhost:9999")
    defer client.Disconnect()
    ctx := context.Background()
    // Connect with authenticate
    auth := gqtt.WithLoginAuth("admin", "admin")
    if err := client.Connect(ctx, auth); err != nil {
        log.Fatal(err)
    }
    // Subscribe topic
    if err := client.Subscribe("gqtt/example", message.QoS2); err != nil {
        log.Fatal(err)
    }
    ticker := time.NewTicker(3 * time.Second)
    for {
        select {
        case <-client.Closed:
            log.Println("connection closed")
            return
        case <-ctx.Done():
            log.Println("context canceled")
            return
        case msg := <-client.Message:
            log.Printf("published message received: %s\n", string(msg.Body))
        case <-ticker.C:
            log.Printf("message publish")
            if err := client.Publish("gqtt/example", []byte("Hello, MQTT5!"), gqtt.WithQoS(message.QoS2)); err != nil {
                return
            }
        }
    }
}

See more examples in detail.

Features

This package now implements partial features. See following checks:

• QoS0 message
• QoS1 message (but not persistent storage, only store on memory)
• QoS2 message (but not persistent storage, only store on memory)
• Retain message (but not persistent storage, only store on memory)
• Will message
• Wildcard topics
• User Property
• MQTT over WebSocket
• Connect redirection
• Request/Response feature
• Auth challenge (now experimental. Only basic/login auth with admin/admin)
• Distirbuted brokers

LICENSE

MIT

Author

Yoshiaki Sugimoto

This package is still under development. PR is welcome :-)