Added multiple proxies interoperability

[stanley-cheung]

1. Added multiple proxies interoperabilty
   • Envoy, Nginx, GrpcWebProxy
2. Added "binary" mode to client. So the client can be configured in 2 different ways now. See spec for details.
   • Default: Content-Type: application/grpc-web-text
     • Pass in mode=grpcwebtext in the code generator
     • Payload are base64-encoded for both requests and responses
     • Support unary and server streaming calls.
   • Binary: Content-Type: application/grpc-web+proto
     • Pass in mode=grpcweb in the code generator
     • Payload are in binary protobuf format
     • Only unary calls are supported for now.

[johanbrandhorst]

So pleased to finally see this interoperability done! Well done! This affects #91.

[johanbrandhorst]

I think this should download a released version rather than just using go get.

https://github.com/improbable-eng/grpc-web/archive/0.6.2.tar.gz

Then download dep and run dep ensure as done here.

[stanley-cheung]

Sorry wasn't very familiar with go get. Tried a bit just now and couldn't get it to work. Can you show me an example on how that's done?

I tried to download the tarball. Untar it. Which directory should I be running dep ensure from? Do I need another go get command after that?

[johanbrandhorst]

A complete installation would be:

# Install stable dep
curl https://raw.githubusercontent.com/golang/dep/master/install.sh | sh
# Install stable proxy
wget https://github.com/improbable-eng/grpc-web/archive/0.6.2.tar.gz
tar xfv 0.6.2.tar.gz /go/src/github.com/improbable-eng/
cd /go/src/github.com/improbable-eng/grpc-web
dep ensure --vendor-only
# Build and install into /go/bin/grpcwebproxy
go install ./go/grpcwebproxy

Something like this. I haven't tried it, just writing from memory, but shouldn't be far off.

[stanley-cheung]

Thanks! I made the change and that seems to do it.