How To Configure Queue Name for Queue Trigger In Azure Function App

Question

I'm creating a function app in Azure and want to use a queue trigger. I know how to configure the queue name at design time, e.g:

[FunctionName("MyTestFunction")]  public static void Run([QueueTrigger("myqueue-items", Connection = "testdelete")]string myQueueItem, TraceWriter log)

However, I'd like to be able to define and reference it in a configuration file. I'm aware of the existence of function.json (Probably this one), host.json and local.settings.json, but I don't know how to set a queue name in there and have it be referenced in the function.

If I deploy a freshly created function created in visual studio (With the new 15.3 update), I can see the following in the function.json file post deployment (even though the file doesn't exist when i develop locally):

  "bindings": [      {        "type": "queueTrigger",        "queueName": "myqueue-items",        "connection": "testdelete",        "name": "myQueueItem"      }

I've found that if I create that file, and change the "queueName" to something that doesn't match the value in the actual function, it unfortunately doesn't override it (That would have been too easy I guess).

How can I reference the bindings in the function.json in the functions QueueTrigger attribute?

Presumably whatever the solution is will allow me to do the same with poison queue handling?

The reason I want to do this, is because I need to deploy multiple instances of the exact same function, but pointing each one at a different queue (In order to get around max memory limitations).

Thanks.

Answer 1

Could you not just reference the queue name as a setting (using the %settingName% syntax) for your App Function? Then in each function app you deploy have change the setting to the required queue name.

[FunctionName("MyTestFunction")] public static void Run([QueueTrigger("%MyQueueName%", Connection = "testdelete")]string myQueueItem, TraceWriter log) 

And specify the setting in local.settings.json for running locally

{   "Values: {      "MyQueueName": "myqueue-items"    } }