Possible to retrieve peer info?

[eberkund]

With grpc-go I can get peer info like so:

p, ok := peer.FromContext(ctx)
if !ok {
    return nil, errors.New("could not get peer from context")
}
addr := p.Addr.String()

Is it possible to do this with connect-go?

I am trying to get the IP that the request is originating from.

Thanks

[akshayjshah]

Currently, it's possible but not super-simple. You'd need to write a small piece of net/http middleware to attach the HTTP Request.RemoteAddr to the context, then pull it off the context and include it in your logs.

I'm open to exposing this in handlers with an easier-to-use API, but I'd like to see what else people expect to do with this information. For example, we don't have any current plans to expose an equivalent to the grpc.Peer call options.

[clly]

Some potential usages I can think of include per IP rate limiting, caching, or naive authorization.

It might be nicer to include it in the request object like the headers are. It makes them more explicit, less magical, and easier to use.

[eberkund]

A middleware like @akshayjshah suggested indeed works for anyone who comes across this issue. This is how I implemented it:

type remoteAddrKey struct{}

func addRemoteAddr(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		ctx := context.WithValue(r.Context(), remoteAddrKey{}, r.RemoteAddr)
		next.ServeHTTP(w, r.WithContext(ctx))
	})
}

Make sure you wrap your handler in the middleware (like any other HTTP middleware in Go):

mux.Handle(path, addRemoteAddr(handler))

And then in your handler:

remoteAddr, ok := ctx.Value(remoteAddrKey{}).(string)

[eberkund]

But besides the option above, is there a way to get the remote address without the middleware?

I saw the IP address is already in the context when I was playing around with my debugger but I just didn't get to a point of figuring out how to extract it.

[akshayjshah]

I saw the IP address is already in the context when I was playing around with my debugger but I just didn't get to a point of figuring out how to extract it.

Nothing in connect-go is putting the IP onto the context, and AFAIK nothing in net/http is either.

[akshayjshah]

Opened a PR that exposes this info on Request, AnyRequest, StreamingClientConn, StreamingHandlerConn, and the relevant wrappers. @clly, we're definitely not attaching anything to the context!

Usage looks like this:

type PingServer struct {}

func (p *PingServer) Ping(
  ctx context.Context,
  request *connect.Request[pingv1.PingRequest],
) (*connect.Response[pingv1.PingResponse], error) {
  fmt.Println(request.Peer().Addr) // <-- this is new!
  return connect.NewResponse(&pingv1.PingResponse{
    Number: request.Msg.Number,
  }), nil
}

[akshayjshah]

Released in v0.5.0!