Unable to write message to Service Bus Queue from Azure Function

Question

I'm trying to follow the documentation to write a message to an Azure Service Bus queue from an Azure Function ( https://docs.microsoft.com/en-us/azure/azure-functions/functions-bindings-service-bus-output?tabs=csharp ).

I started off with the "File->New Project" for an HTTP Trigger and added the binding:

[FunctionName("Message")]
[return: ServiceBus("namequeue")]
public static async Task<string> Run(
    [HttpTrigger(AuthorizationLevel.Anonymous, "post", Route = null)] HttpRequest req,
    ILogger log)
{
    log.LogInformation("C# HTTP trigger function processed a request.");

    string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
    dynamic data = JsonConvert.DeserializeObject(requestBody);
    string name = data?.name ?? "DefaultName";

    return name;
}

My host.json and local.settings.json file contains:

"extensions": {
    "serviceBus": {
        "prefetchCount": 100,
        "messageHandlerOptions": {
            "autoComplete": true,
            "maxConcurrentCalls": 32,
            "maxAutoRenewDuration": "00:05:00"
        },
        "sessionHandlerOptions": {
            "autoComplete": false,
            "messageWaitTimeout": "00:00:30",
            "maxAutoRenewDuration": "00:55:00",
            "maxConcurrentSessions": 16
        },
        "batchOptions": {
            "maxMessageCount": 1000,
            "operationTimeout": "00:01:00",
            "autoComplete": "true"
        }
    }
},
"Values": {
    "AzureWebJobsServiceBus": "Endpoint=<redacted>"
}

When running locally I get a timeout exception (which might be a corporate firewall).

When deployed to Azure, I can POST to the function, get a 204 reply, but no messages are added to the queue.

I think I've missed a key step as my function.json in the Azure Portal has:

{
  "generatedBy": "Microsoft.NET.Sdk.Functions-3.0.13",
  "configurationSource": "attributes",
  "bindings": [
    {
      "type": "httpTrigger",
      "methods": [
        "post"
      ],
      "authLevel": "anonymous",
      "name": "req"
    }
  ],
  "disabled": false,
  "scriptFile": "../bin/AppMapServiceBusCreate.dll",
  "entryPoint": "AppMapServiceBus.CreateMessageFunction.Run"
}

And when I click on Integration within the Portal there are no output and adding one gives me a warning of "In order to see the entire list of available function templates, you must set up extension bundles for your app.".

I thought Extension Bundles were non .NET code and the fact I've added the following via NuGet did the same thing?

<PackageReference Include="Microsoft.Azure.WebJobs.Extensions.ServiceBus" Version="4.3.0" />

If that's accurate, how/what do I add to the function.json?

Answer 1

For Azure Functions using an output trigger to write to Service Bus, you'll need to add the connection string as an application setting in the function's configuration. By default , the expected setting name is AzureWebJobsServiceBus :