Myriota device Uplink Serialisation

The Myriota Developer documentation has some sample webhook data payloads so I used JSON2csharp to generate a Data Transfer Object(DTO) to deserialise payload. The format of the message is a bit “odd”, the “Data “Value” contains an “escaped” JSON object.

{
  "EndpointRef": "ksnb8GB_TuGj:__jLfs2BQJ2d",
  "Timestamp": 1692928585,
  "Data": "{"Packets": [{"Timestamp": 1692927646796, "TerminalId": "0001020304", "Value": "00008c9512e624cce066adbae764cccccccccccc"}]}",
  "Id": "a5c1bffe-4b62-4233-bbe9-d4ecc4f8b6cb",
  "CertificateUrl": "https://security.myriota.com/data-13f7751f3c5df569a6c9c42a9ce73a8a.crt",
  "Signature": "FDJpQdWHwCY+tzCN/WvQdnbyjgu4BmP/t3cJIOEF11sREGtt7AH2L9vMUDji6X/lxWBYa4K8tmI0T914iPyFV36i+GtjCO4UHUGuFPJObCtiugVV8934EBM+824xgaeW8Hvsqj9eDeyJoXH2S6C1alcAkkZCVt0pUhRZSZZ4jBJGGEEQ1Gm+SOlYjC2exUOf0mCrI5Pct+qyaDHbtiHRd/qNGW0LOMXrB/9difT+/2ZKE1xvDv9VdxylXi7W0/mARCfNa0J6aWtQrpvEXJ5w22VQqKBYuj3nlGtL1oOuXCZnbFYFf4qkysPaXON31EmUBeB4WbZMyPaoyFK0wG3rwA=="
}
namespace devMobile.IoT.myriotaAzureIoTConnector.myriota.UplinkWebhook.Models
{
    public class UplinkPayloadWebDto
    {
        public string EndpointRef { get; set; }
        public long Timestamp { get; set; } 
        public string Data { get; set; } // Embedded JSON ?
        public string Id { get; set; }
        public string CertificateUrl { get; set; }
        public string Signature { get; set; }
    }
}

The UplinkWebhook controller “automagically” deserialises the message, then in code the embedded JSON is deserialised and “unpacked”, finally the processed message is inserted into an Azure Storage queue.

namespace devMobile.IoT.myriotaAzureIoTConnector.myriota.UplinkWebhook.Controllers
{
    [Route("[controller]")]
    [ApiController]
    public class UplinkController : ControllerBase
    {
        private readonly Models.ApplicationSettings _applicationSettings;
        private readonly ILogger<UplinkController> _logger;
        private readonly QueueServiceClient _queueServiceClient;

        public UplinkController(IOptions<Models.ApplicationSettings> applicationSettings, QueueServiceClient queueServiceClient, ILogger<UplinkController> logger)
        {
            _applicationSettings = applicationSettings.Value;
            _queueServiceClient = queueServiceClient;
            _logger = logger;
        }

        [HttpPost]
        public async Task<IActionResult> Post([FromBody] Models.UplinkPayloadWebDto payloadWeb)
        {
            _logger.LogInformation("SendAsync queue name:{QueueName}", _applicationSettings.QueueName);

            QueueClient queueClient = _queueServiceClient.GetQueueClient(_applicationSettings.QueueName);

            var serializeOptions = new JsonSerializerOptions
            {
                WriteIndented = true,
                Encoder = System.Text.Encodings.Web.JavaScriptEncoder.UnsafeRelaxedJsonEscaping
            };

            await queueClient.SendMessageAsync(Convert.ToBase64String(JsonSerializer.SerializeToUtf8Bytes(payloadWeb, serializeOptions)));

            return this.Ok();
        }
    }
}

The webhook application uses the QueueClientBuilderExtensions and AddServiceClient so a QueueServiceClient can be injected into the webhook controller.

namespace devMobile.IoT.myriotaAzureIoTConnector.myriota.UplinkWebhook
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var builder = WebApplication.CreateBuilder(args);

            // Add services to the container.
            builder.Services.AddControllers();

            builder.Services.AddApplicationInsightsTelemetry(i => i.ConnectionString = builder.Configuration.GetConnectionString("ApplicationInsights"));

            builder.Services.Configure<Models.ApplicationSettings>(builder.Configuration.GetSection("Application"));

            builder.Services.AddAzureClients(azureClient =>
            {
                azureClient.AddQueueServiceClient(builder.Configuration.GetConnectionString("AzureWebApi"));
            });

            var app = builder.Build();

            // Configure the HTTP request pipeline.

            app.UseHttpsRedirection();

            app.MapControllers();

            app.Run();
        }
    }
}

After debugging the application on my desktop with Telerik fiddler I deployed the application to one of my Azure subscriptions.

Azure Resource Group for the myriota Azure IoT Connector
Adding a new Destination in the myriota device manager

As part of configuring a new device test messages can be sent to the configured destinations.

Testing a new Destination in the myriota device manager
{
  "EndpointRef": "N_HlfTNgRsqe:uyXKvYTmTAO5",
  "Timestamp": 1563521870,
  "Data": "{"Packets": [{"Timestamp": 1563521870359,
    "TerminalId": "f74636ec549f9bde50cf765d2bcacbf9",
    "Value": "0101010101010101010101010101010101010101"}]}",
  "Id": "fe77e2c7-8e9c-40d0-8980-43720b9dab75",
  "CertificateUrl":    "https://security.myriota.com/data-13f7751f3c5df569a6c9c42a9ce73a8a.crt",
  "Signature": "k2OIBppMRmBT520rUlIvMxNg+h9soJYBhQhOGSIWGdzkppdT1Po2GbFr7jbg..."
}

The DTO generated with JSON2csharp needed some manual “tweaking” after examining how a couple of the sample messages were deserialised.

Azure Storage Explorer messages

I left the Myriota Developer Toolkit device (running the tracker sample) outside overnight and the following day I could see with Azure Storage Explorer a couple of messages in the Azure Storage Queue

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