gqtt

README

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 :-)

Documentation

Index

• func NewBroker(addr string) *broker.Broker
• func NewClient(url string) *client.Client
• type Option
  • func WithBasicAuth(user, password string) Option
  • func WithLoginAuth(user, password string) Option
  • func WithQoS(qos message.QoSLevel) Option
  • func WithRetain() Option
  • func WithWill(qos message.QoSLevel, retain bool, topic, payload string, ...) Option
• type Topic

Functions

func NewBroker

func NewBroker(addr string) *broker.Broker

func NewClient

func NewClient(url string) *client.Client

Types

type Option

type Option = client.ClientOption

func WithBasicAuth

func WithBasicAuth(user, password string) Option

func WithLoginAuth

func WithLoginAuth(user, password string) Option

func WithQoS

func WithQoS(qos message.QoSLevel) Option

func WithRetain

func WithRetain() Option

func WithWill

func WithWill(qos message.QoSLevel, retain bool, topic, payload string, property *message.WillProperty) Option

type Topic

type Topic = message.SubscribeTopic