Expose a way to pass Name of Factory Client to Function Triggers

[jonmeyerson]

Library name

Microsoft.Azure.Functions.Worker

Please describe the feature.

Feature Request:

Currently when using a ServiceBusTrigger you need to specify the Connection String - It would be nice if we could instead pass the name of a Factory Client and it would be able to proceed from there. This internally could rely on the IAzureClientFactory for DI.
This could also be extended to other clients that have connections like BlobTrigger/QueueTrigger

services.AddAzureClients((factoryBuilder) =>
{
    factoryBuilder
        .AddClient<ServiceBusClient, ServiceBusClientOptions>((options, serviceProvider) =>
        {
            string Connectionstring = //custom logic. 
            return new ServiceBusClient(Connectionstring, options);
        })
        .WithName("ServiceBusClientName");
    factoryBuilder
         .AddClient<ServiceBusReceiver, ServiceBusReceiverOptions>((options, serviceProvider) =>
         {
             var factory = serviceProvider.GetRequiredService<IAzureClientFactory<ServiceBusClient>>();
             var client = factory.CreateClient("ServiceBusClientName");
             return client.CreateReceiver("QueueName", options);
          }).WithName(ServiceBusReceiverClientName);
});

public string ServiceBusReceivedMessageFunction(
      [ServiceBusTrigger(ClientName = "ServiceBusReceiverClientName")] ServiceBusReceivedMessage message)
{
      var outputMessage = $"Output message created at {DateTime.Now}";
      return outputMessage;
}

Problem being solved:
Able to use DI to setup the Connection AND options.

And in the future something like this could be registered and tied to a new Trigger [ServiceBusTrigger(ClientName = "ServiceBusSession1", IsSessionsEnabled = true)]

factoryBuilder.AddClient<ServiceBusSessionProcessor, ServiceBusSessionProcessorOptions>((options, serviceProvider) =>
{
    var factory = serviceProvider.GetRequiredService<IAzureClientFactory<ServiceBusClient>>();
    var _options = serviceProvider.GetRequiredService<IOptions<MyOptions>>();
    var client = factory.CreateClient(MyOptions.ClientName);
    options = new ServiceBusSessionProcessorOptions
    {
        MaxConcurrentSessions = _options.Value.MaxConcurrentSessions,
        MaxConcurrentCallsPerSession = 1,//Guarantees order.
        ReceiveMode = ServiceBusReceiveMode.ReceiveAndDelete,
        PrefetchCount = _options.Value.PrefetchCount,
        MaxAutoLockRenewalDuration = _options.Value.SessionTimeToLive //Prevent session starvation.
    };
    return client.CreateSessionProcessor(_options.Value.TopicName, _options.Value.SubscriptionName, options);
}).WithName("ServiceBusSession1");

Currently options for servicebustrigger are only configurable in host.json, this would allow them to pull from here.

Edit:
It looks the the ServiceBusListener used by the current ServiceBusTrigger is using MessagingProvider as a factory, instead of registering them to the IAzureClientFactory<> and retrieving them from there. There is also a separate class ServiceBusClientFactory also using MessagingProvider. currently it is using a concurrent dictionary with a key generated by entityPath which is generated by the code based on inputs.

[github-actions]

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