/// <inheritdoc cref="IMqttRepositoryGrain" />
/// <summary>
/// Connects a broker to the grain.
/// </summary>
/// <param name="brokerConnectionSettings">The broker connection settings.</param>
/// <param name="brokerId">The broker identifier.</param>
/// <exception cref="ArgumentNullException">Thrown when the broker connection settings or the broker identifier is <c>null</c>.</exception>
/// <seealso cref="IMqttRepositoryGrain" />
public Task ConnectBroker(IBrokerConnectionSettings brokerConnectionSettings, Guid brokerId)
{
if (brokerConnectionSettings == null)
{
#pragma warning disable IDE0016 // throw-Ausdruck verwenden
throw new ArgumentNullException(nameof(brokerConnectionSettings));
#pragma warning restore IDE0016 // throw-Ausdruck verwenden
}
if (brokerId == null)
{
throw new ArgumentNullException(nameof(brokerId));
}
// Save connect to the database
var eventLog = new EventLog
{
EventType = EventType.BrokerConnect,
EventDetails = $"New broker connected: BrokerId = {brokerId}."
};
this.eventLogQueue.Enqueue(eventLog);
// Add to dictionary
this.brokers[brokerId] = brokerConnectionSettings;
return(Task.CompletedTask);
}
/// <inheritdoc cref="IMqttRepositoryGrain" />
/// <summary>
/// Connects a broker to the grain.
/// </summary>
/// <param name="brokerConnectionSettings">The broker connection settings.</param>
/// <param name="brokerId">The broker identifier.</param>
/// <seealso cref="IMqttRepositoryGrain" />
public async void ConnectBroker(IBrokerConnectionSettings brokerConnectionSettings, Guid brokerId)
{
try
{
// Save connect to the database
var eventLog = new EventLog
{
EventType = EventType.BrokerConnect,
EventDetails = $"New broker connected: BrokerId = {brokerId}."
};
await this.eventLogRepository.InsertEventLog(eventLog);
// Add to dictionary
this.brokers[brokerId] = brokerConnectionSettings;
}
catch (Exception ex)
{
this.logger.Error("An error occured: {ex}.", ex);
}
}
/// <summary>
/// Publishes a message to a remote broker that hasn't initially sent the message to the cluster.
/// </summary>
/// <param name="context">The context.</param>
/// <param name="brokerConnectionSettings">The broker connection settings.</param>
/// <returns>A <see cref="Task" /> representing asynchronous operation.</returns>
private static async Task PublishMessageToBroker(MqttApplicationMessageInterceptorContext context, IBrokerConnectionSettings brokerConnectionSettings)
{
if (context.ApplicationMessage == null)
{
return;
}
// Create a new MQTT client
var factory = new MqttFactory();
var mqttClient = factory.CreateMqttClient();
var optionsBuilder = new MqttClientOptionsBuilder().WithClientId(brokerConnectionSettings.ClientId).WithTcpServer(brokerConnectionSettings.HostName, brokerConnectionSettings.Port)
.WithCredentials(brokerConnectionSettings.UserName, brokerConnectionSettings.Password).WithCleanSession(brokerConnectionSettings.UseCleanSession);
if (brokerConnectionSettings.UseTls)
{
optionsBuilder.WithTls();
}
var options = optionsBuilder.Build();
// Deserialize payload
var payloadString = context.ApplicationMessage?.Payload == null ? string.Empty : Encoding.UTF8.GetString(context.ApplicationMessage.Payload);
// Connect the MQTT client
await mqttClient.ConnectAsync(options, CancellationToken.None);
// Send the message
var message = new MqttApplicationMessageBuilder().WithTopic(context.ApplicationMessage.Topic).WithPayload(payloadString).WithQualityOfServiceLevel(context.ApplicationMessage.QualityOfServiceLevel)
.WithRetainFlag(context.ApplicationMessage.Retain).Build();
await mqttClient.PublishAsync(message, CancellationToken.None);
await mqttClient.DisconnectAsync(null, CancellationToken.None);
}