Support for Middlewares

[tonychengchime]

Hi, does Twirpy support Middlewares like Starlette? I'm trying to implement an auth layer and would like to do it in a Middleware.

I did not see in the documentation or code where to specify them.

Thanks

[ofpiyush]

Hi @tonychengchime, thanks for reaching out.

Yes! Twirp has support for both "middlewares" and hooks. They're nothing like the ones you see in Starlette though. And for your use case, they're not ideal.

For more nuanced use cases, twirp has the concept of hooks.
This is how it looks like in go: https://pkg.go.dev/github.com/twitchtv/twirp#ServerHooks

Equivalent implementation in python. https://github.com/verloop/twirpy/blob/0.0.7/twirp/hook.py

You can pass a hook with the kwarg like so, TwirpAsgiApp(hook=MyHook).

Since you want to do auth, you can use request_received or request_routed hook. Both of them run before the request body is read at all.

You can raise a TwirpServerException with Unauthenticated or PermissionDenied code from within your hook.

I can post a more complete example tomorrow if that'll help.

[tonychengchime]

Hi Piyush, that was very helpful. I got what I need so I will close this ticket. Thanks

[ofpiyush]

Today I got some time to check starlette's middlewares again.

@tonychengchime check the "Using middleware in other frameworks" section on https://www.starlette.io/middleware/

Twirpy is a standard ASGI app, so it should work for youad well.