/// <summary>
/// Ctor for the singleton class.
/// </summary>
internal IotHubCommunication()
{
// check if we got an IoTHub owner connection string
if (string.IsNullOrEmpty(IotHubOwnerConnectionString))
{
Logger.Information("IoT Hub owner connection string not passed as argument.");
// check if we have an environment variable to register ourselves with IoT Hub
if (!string.IsNullOrEmpty(Environment.GetEnvironmentVariable("_HUB_CS")))
{
IotHubOwnerConnectionString = Environment.GetEnvironmentVariable("_HUB_CS");
Logger.Information("IoT Hub owner connection string read from environment.");
}
}
Logger.Information($"IoTHub device cert store type is: {IotDeviceCertStoreType}");
Logger.Information($"IoTHub device cert path is: {IotDeviceCertStorePath}");
if (string.IsNullOrEmpty(IotHubOwnerConnectionString))
{
Logger.Information("IoT Hub owner connection string not specified. Assume device connection string already in cert store or passed in via command line option.");
}
else
{
if (string.IsNullOrEmpty(DeviceConnectionString))
{
Logger.Information($"Attempting to register ourselves with IoT Hub using owner connection string.");
RegistryManager manager = RegistryManager.CreateFromConnectionString(IotHubOwnerConnectionString);
// remove any existing device
Device existingDevice = manager.GetDeviceAsync(ApplicationName).Result;
if (existingDevice != null)
{
Logger.Information($"Device '{ApplicationName}' found in IoTHub registry. Remove it.");
manager.RemoveDeviceAsync(ApplicationName).Wait();
}
Logger.Information($"Adding device '{ApplicationName}' to IoTHub registry.");
Device newDevice = manager.AddDeviceAsync(new Device(ApplicationName)).Result;
if (newDevice != null)
{
Logger.Information($"Generate device connection string.");
string hostname = IotHubOwnerConnectionString.Substring(0, IotHubOwnerConnectionString.IndexOf(";", StringComparison.InvariantCulture));
DeviceConnectionString = hostname + ";DeviceId=" + ApplicationName + ";SharedAccessKey=" + newDevice.Authentication.SymmetricKey.PrimaryKey;
}
else
{
string errorMessage = $"Can not register ourselves with IoT Hub. Exiting...";
Logger.Fatal(errorMessage);
throw new Exception(errorMessage);
}
}
else
{
Logger.Information($"There have been a device connectionstring specified on command line. Skipping device creation in IoTHub. Please ensure you created a device with name '{ApplicationName}' manually.");
}
}
// save the device connectionstring, if we have one
if (!string.IsNullOrEmpty(DeviceConnectionString))
{
Logger.Information($"Adding device connectionstring to secure store.");
SecureIoTHubToken.WriteAsync(ApplicationName, DeviceConnectionString, IotDeviceCertStoreType, IotDeviceCertStorePath).Wait();
}
// try to read connection string from secure store and open IoTHub client
Logger.Information($"Attempting to read device connection string from cert store using subject name: {ApplicationName}");
DeviceConnectionString = SecureIoTHubToken.ReadAsync(ApplicationName, IotDeviceCertStoreType, IotDeviceCertStorePath).Result;
if (string.IsNullOrEmpty(DeviceConnectionString))
{
string errorMessage = $"Device connection string not found in secure store. Please pass it in at least once via command line option. Can not connect to IoTHub. Exiting...";
Logger.Fatal(errorMessage);
throw new ArgumentException(errorMessage);
}
// connect as device client
Logger.Information($"Create device client using '{HubProtocol}' for communication.");
IotHubClient = HubClient.CreateDeviceClientFromConnectionString(DeviceConnectionString, HubProtocol, Logger);
if (!InitHubCommunicationAsync(IotHubClient, true, true).GetAwaiter().GetResult())
{
string errorMessage = $"Cannot create IoTHub client. Exiting...";
Logger.Fatal(errorMessage);
throw new Exception(errorMessage);
}
}