Supported bindings for Singleton scopeId on HTTP Trigger Azure Function

I am unclear on how the scopeId parameter of the SingletonAttribute works. Specifically does the scopeId parameter work for HTTP Trigger Azure Functions when you bind it to a route parameter? How does the binding work? What variables/values can I bind to?

For example:

[Singleton("{input}", Mode = SingletonMode.Listener)]  public async Task<IActionResult> Run([HttpTrigger(AuthorizationLevel.Anonymous, "post", Route = "v1/{input:length(1,30)}")] Microsoft.AspNetCore.Http.HttpRequest req, string input, ILogger log) {      return new OkObjectResult(input + " world");  }  

A HTTP POST request to this function with the URI 'v1/hello' would return: "Hello world".

But would the Singleton attribute work such that all requests to 'v1/hello' would run serially whereas two simultaneous requests with one to 'v1/first' and the other to 'v1/second' would run in parallel?

I see from this answer that for Service Bus Triggers you can bind to properties within the Message object directly.
Also in the documentation there is an example of a Queue Trigger Function with scopeId binding to a property in the WorkItem object.
It's unclear what's supported for HTTP Trigger Functions.

https://stackoverflow.com/questions/65745130/supported-bindings-for-singleton-scopeid-on-http-trigger-azure-function January 16, 2021 at 08:05AM