Lucio Franco

@carllerche i think we need to figure out a `tower-http-connection` crate to provide a type alias for http connections.

Initial work is being worked on here https://github.com/tower-rs/tower-http/pull/19

@davidvartan sorry this TLS work has taken a long time as we have been distracted moving to std::Future. What issues are you running into with TLS/ALPN?

So I'm not sure the http_connector from hyper does ALPN negotiation. That said, you should be able to use this example + `MakeConnection` to produce a `AsyncRead + AsyncWrite` stream...

@kcking hi thanks for the issue! I have not looked too deep at grpc-go's interceptors yet, is this something that would work at the http2 level aka intercepting `http::Request` and...

So `MetadataMap` is 1:1 with `http::HeadersMap`. So that should be easy to provide a tower-request-modifier where you can update the metadata, the issue is the body but I don think...

@kcking so I think we could provide a middleware that actually will go from http -> tower-grpc request/responses types then its trivial for a user to implement the same interceptors....

@kcking soon for futures 0.3! 😄 So we have these internal fns https://github.com/tower-rs/tower-grpc/blob/master/tower-grpc/src/request.rs#L44 we could provide a Service that does this mapping for you and takes a `fn(&mut tower_grpc::Request)` and...

Reference https://github.com/tower-rs/tower-grpc/pull/208#issuecomment-535052437

Here is an example of a tower middlware being applied to a grpc client. https://github.com/tower-rs/tower-grpc/blob/master/tower-grpc-examples/src/helloworld/client.rs#L29