Azure function worker isolated process .NET 6 - work with servicebus and servicebus trigger

Question

I'm working with Azure Function isolated process .net 6.

I have an issue to work with the service bus and service bus trigger.

If in-process I will declare like this

public async Task<ActionResult> Run([HttpTrigger(AuthorizationLevel.Function, "post", Route = null)]HttpRequest req, ILogger log, ExecutionContext context,
    [ServiceBus("mail-sender", Connection = "ServiceBusConnection")] IAsyncCollector<dynamic> outgoingMessage)
{
    ... outgoingMessage.Send(mymessage);...
}

And then I will have another service bus trigger azure function to process the message like this

   public void Run([ServiceBusTrigger("mail-sender", Connection = "ServiceBusConnection")]string myQueueItem, ILogger log)
        {
            try
            {
                var mailHost = Environment.GetEnvironmentVariable("MAIL_HOST") ?? "smtp.sendgrid.net";
                var mailPort = Convert.ToInt32(Environment.GetEnvironmentVariable("MAIL_PORT") ?? "587");
                var mailUsername = Environment.GetEnvironmentVariable("MAIL_USERNAME") ?? "apikey";
                var mailPassword = Environment.GetEnvironmentVariable("MAIL_PASSWORD") ?? "8755faf7-78c9-4389-b3a5-f1578953bc00";
                var ssl = Convert.ToBoolean(Environment.GetEnvironmentVariable("MAIL_SSL") ?? "false");

                using (var mailHelpers = new MailHelpers(mailHost, mailPort, mailUsername, mailPassword, ssl))
                {
                    var mail = JsonConvert.DeserializeObject<MailViewModel>(myQueueItem);
                    mailHelpers.Send(mail);
                }
            }
            catch (Exception ex)
            {
                log.LogError(ex, "Error during sending email.");
            }
        }

How can I achieve that in the azure function isolated process?

Please help me to give example detail and the package's dependencies if any.

Many thanks

===========================

BTW, I have declare TimerTrigger azure function, it uses https://www.nuget.org/packages/Microsoft.Azure.Functions.Worker.Extensions.Timer It can trigger the task to run, but I cannot debug it? I'm not sure why?

        public async Task<DispatchedMessages> Run([TimerTrigger("* * * * * *")] MyInfo myTimer)
        {
            try
            {...}
        }

Answer 1

As I understand your question, the flow will look like something like this:

1. post to Httptrigger
2. the HttpTrigger will queue a message in some service bus queue (for detail about how to post a message to the queue see the documentation) Here is how you can send a message to a service bus queue:

using Azure.Messaging.ServiceBus;

public class ServiceBusAdapter
    {
        private readonly ServiceBusClient _client;

        public ServiceBusAdapter(ServiceBusClient client)
        {
            _client = client;
        }

        public async Task SendMessage(string queueName, BinaryData body, string? messageId = null)
        {
            ServiceBusMessage sbMessage = CreateServiceBusMessage(body, messageId);
            await using ServiceBusSender sender = _client.CreateSender(queueName);

            try
            {
                await sender.SendMessageAsync(CreateServiceBusMessage(body, messageId));
            }
            catch (ServiceBusException e) when (e.IsTransient)
            {
                throw new SomeCustomException(e.Message, e);
            }
        }

        public async Task SendMessages(string queueName, IEnumerable<Message> messages)
        {
            Queue<ServiceBusMessage> sbMessages = new(messages.Select(m => CreateServiceBusMessage(m.Body, m.MessageId)));
            await using ServiceBusSender sender = _client.CreateSender(queueName);

            // While all messages are not sent to the Service Bus queue
            while (sbMessages.Count > 0)
            {
                // Start a new batch
                using ServiceBusMessageBatch messageBatch = await sender.CreateMessageBatchAsync();

                // Add the first message to the batch
                if (messageBatch.TryAddMessage(sbMessages.Peek()))
                {
                    // Dequeue the message from the .NET queue once the message is added to the batch
                    sbMessages.Dequeue();
                }
                else
                {
                    // If the first message can't fit, then it is too large for the batch.
                    // Try to send it anyway so that we get a proper service bus exception.
                    await sender.SendMessageAsync(sbMessages.Dequeue());
                    continue;
                }

                // Add as many messages as possible to the current batch
                while (sbMessages.Count > 0 && messageBatch.TryAddMessage(sbMessages.Peek()))
                {
                    // Dequeue the message from the .NET queue as it has been added to the batch
                    sbMessages.Dequeue();
                }

                try
                {
                    // Now, send the batch
                    await sender.SendMessagesAsync(messageBatch);
                }
                catch (ServiceBusException e) when (e.IsTransient)
                {
                    throw new SomeCustomException(e.Message, e);
                }

                // If there are any remaining messages in the .NET queue, the while loop repeats
            }
        }

        private static ServiceBusMessage CreateServiceBusMessage(BinaryData body, string? messageId)
        {
            var message = new ServiceBusMessage(body);

            if (messageId is not null)
            {
                // Service Bus (Standard and Premium SKU but not Basic) finds
                // duplicates by this MessageId
                message.MessageId = messageId;
            }

            return message;
        }
    }

3. once the message is queued the service bus will notify the ServiceBusTrigger that is configured and listening to that queue.

Here is an example of a ServiceBusTrigger in .net 6 isolated functions:

using Microsoft.Azure.Functions.Worker;
using Microsoft.Extensions.Logging;

namespace Functions.Sample
{
    public class SampleServiceBusTrigger
    {
        private readonly ILogger _logger;
        private const string QueueName = "My.Sample.Queue.Name";

        private readonly ISomeHandler _someHandler;

        public SampleServiceBusTrigger(
            ILoggerFactory loggerFactory,
            ISomeHandler someHandler)
        {
            _logger = loggerFactory.CreateLogger<SampleServiceBusTrigger>();
            _someHandler = someHandler;
        }

        [Function(nameof(SampleServiceBusTrigger))]
        public async Task RunAsync(
            [ServiceBusTrigger(QueueName)] MyObject outMessage)
        {
            _logger.LogInformation("Triggered...");
            await _someHandler.Execute(outMessage);
            _logger.LogInformation("Completed.");
        }
    }
}

You will also need to add these configs to your local.settings.json for local development:

"FUNCTIONS_WORKER_RUNTIME": "dotnet-isolated",
"AzureWebJobsServiceBus": "<YOUR SB CONNECTION STRING>",