Go examples

Enqueue downlink

The example below demonstrates:

Configuration of gRPC dial options including API token
Connect to a gRPC API
Define service client (in this case for the DeviceQueueService)
Perform an API call for a service (in this case Enqueue)

main.go

package main

import (
    "context"
    "fmt"

    "google.golang.org/grpc"

    "github.com/brocaar/chirpstack-api/go/v3/as/external/api"
    "github.com/brocaar/lorawan"
)

// configuration
var (
    // This must point to the API interface
    server = "localhost:8080"

    // The DevEUI for which we want to enqueue the downlink
    devEUI = lorawan.EUI64{0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01}

    // The API token (retrieved using the web-interface)
    apiToken = "..."
)

type APIToken string

func (a APIToken) GetRequestMetadata(ctx context.Context, url ...string) (map[string]string, error) {
    return map[string]string{
        "authorization": fmt.Sprintf("Bearer %s", a),
    }, nil
}

func (a APIToken) RequireTransportSecurity() bool {
    return false
}

func main() {
    // define gRPC dial options
    dialOpts := []grpc.DialOption{
        grpc.WithBlock(),
        grpc.WithPerRPCCredentials(APIToken(apiToken)),
        grpc.WithInsecure(), // remove this when using TLS
    }

    // connect to the gRPC server
    conn, err := grpc.Dial(server, dialOpts...)
    if err != nil {
        panic(err)
    }

    // define the DeviceQueueService client
    queueClient := api.NewDeviceQueueServiceClient(conn)

    // make an Enqueue api call
    resp, err := queueClient.Enqueue(context.Background(), &api.EnqueueDeviceQueueItemRequest{
        DeviceQueueItem: &api.DeviceQueueItem{
            DevEui:    devEUI.String(),
            FPort:     10,
            Confirmed: false,
            Data:      []byte{0x01, 0x02, 0x03},
        },
    })
    if err != nil {
        panic(err)
    }

    fmt.Printf("The downlink has been enqueued with FCnt: %d\n", resp.FCnt)
}