taoh / iothub

Azure iothub SDK for golang plus CLI tools

iothub

This repository provides Azure IoT Hub SDK for golang and command line tools for device-to-cloud (iotdevice) and cloud-to-device (iotservice) functionality.

This project in the active development state and if you decided to use it anyway, please vendor the source code.

Only MQTT is available for device-to-cloud communication for because it has many advantages over AMQP and REST: it's stable, widespread, compact and provide many out-of-box features like auto-reconnects.

See TODO list to learn what is missing.

Examples

Send a message from an IoT device:

package main

import (
	"context"
	"log"
	"os"

	"github.com/amenzhinsky/iothub/iotdevice"
	"github.com/amenzhinsky/iothub/iotdevice/transport/mqtt"
)

func main() {
	c, err := iotdevice.NewClient(
		iotdevice.WithTransport(mqtt.New()),
		iotdevice.WithConnectionString(os.Getenv("DEVICE_CONNECTION_STRING")),
	)
	if err != nil {
		log.Fatal(err)
	}

	// connect to the iothub
	if err = c.Connect(context.Background()); err != nil {
		log.Fatal(err)
	}

	// send a device-to-cloud message
	if err = c.SendEvent(context.Background(), []byte(`hello`),
		iotdevice.WithSendProperty("foo", "bar"),
	); err != nil {
		log.Fatal(err)
	}
}

Receive and print messages from IoT devices in a backend application:

package main

import (
	"context"
	"fmt"
	"log"
	"os"

	"github.com/amenzhinsky/iothub/common"
	"github.com/amenzhinsky/iothub/iotservice"
)

func main() {
	c, err := iotservice.NewClient(
		iotservice.WithConnectionString(os.Getenv("SERVICE_CONNECTION_STRING")),
	)
	if err != nil {
		log.Fatal(err)
	}
	log.Fatal(c.SubscribeEvents(context.Background(), func(msg *common.Message) {
		fmt.Printf("%q sends %q", msg.ConnectionDeviceID, msg.Payload)
	}))
}

CLI

The project provides two command line utilities: iothub-device and iothub-sevice. First is for using it on IoT devices and the second manages and interacts with them.

You can perform operations like publishing, subscribing to events and feedback, registering and invoking direct method, etc. straight from the command line.

iothub-service is a iothub-explorer replacement that can be distributed as a single binary opposed to typical nodejs app.

See -help for more details.

Testing

To enable end-to-end testing in the tests directory you need to provide TEST_SERVICE_CONNECTION_STRING which is a shared access policy connection string.

TODO

1. Stabilize API.
2. HTTP transport (files uploading).
3. AMQP transport (batch sending, WS).
4. Grammar check plus better documentation.
5. Rework Subscribe* functions.

Contributing

All contributions are welcome.