How to use middleware with Azure Functions

[foppenm]

Ask any question related to the blog post here 😊

See the blog @ https://re-mark-able.net when published

[simirajsp]

I am trying to do some decryption/ encryption of my request using middleware (IFunctionsWorkerMiddleware). The invoke method has access to an instance of FunctionContext, but that does not have any methods to access HttpRequestData or HttpResponseData. As I cannot access these properties, I am not able to do encryption/ decryption.

Also for centralized exception handling, I can log to ILogger from context. But If I want to return a custom error message (response code 500, message: An error occurred while executing function), that's also not possible.

I can follow the restrictions here as FunctionContext is built for all triggers and cannot have HTTP-specific properties. But is there any way to access these in pipelines so that I can do the use-cases mentioned above?

[simirajsp]

I think I found my answer from your article itself. There was an open issue mentioned, which I was late to see.

[foppenm]

@simirajsp Yeah the issue is still open but as a workaround you can use: Azure/azure-functions-dotnet-worker#414 (comment)

Not the best solution but it should work until there is a fix.

[Kalyan-Modak]

Hello @foppenm ,

Do we need .Net 5 version to support middleware functionality?

As I'm unable to find ConfigureFunctionsWorkerDefaults method while configuring host.

[StMarian]

Hello, @Kalyan-Modak
It's not about .net version, but rather about in-process vs isolated mode differences. In the in-process, the middleware is not supported.
https://docs.microsoft.com/en-us/azure/azure-functions/dotnet-isolated-process-guide#differences-with-net-class-library-functions

[petrkoutnycz]

Thanks for this article, exactly I was looking for :-)

[NibblyPig]

Is there a way to pass a parameter into the function in this manner, like you can do with ValueProviders in ASP.NET MVC?

So you could add MyObject object as a parameter in your function, and have the middleware populate this automatically?

[shekhar-byte]

I am using azure function with Orchestration trigger. In that case input is not getting binded with binding context which is present in function context. Or is there any different way to access context of orchestration trigger inside middleware