rpc: flatten details field

[BrianHicks]

We don't need a struct details field, just bytes. I also re-read the spec and realized that the google.proto.Any specifies that the content will be protobuf-serialized. We don't have that on the structs we're serializing, so that's changed just a bit.

[ryane]

lgtm. this also fixes graph over rpc for me.

one note: this is already accounted for in the readme but I had been running with protoc 2.6.1 and this pr seems to enforce the 3.x requirement. Just a note for anyone who runs into problems - it took me a while to get my environment sorted out. After trying a bunch of things, I ended up building protoc from source and reinstalling the other rpc dependencies mentioned in the readme.

[stevendborrelli]

@ryane we should have a converge config that installs protoc. I have this as an rpc.hcl:

param "gopath" {
  default = "${HOME}/gopath"
}

task "gopath" {
  description = "Create GOPATH"
  check = "[[ -d {{param `gopath`}} ]]"
  apply = "mkdir -p {{param `gopath`}}"
}

task "install protoc-gen-go" {
  check = "[[ -f {{param `gopath`}}/bin/protoc-gen-go ]]"
  apply = "go get -u github.com/golang/protobuf/protoc-gen-go"
  depends = ["task.gopath"]
}

task "install protoc-gen-grpc-gateway" {
  check = "[[ -f {{param `gopath`}}/bin/protoc-gen-grpc-gateway ]]"
  apply = "go get -u github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway "
  depends = ["task.gopath"]
}

task "install protoc-gen-swagger" {
  check = "[[ -f {{param `gopath`}}/bin/protoc-gen-swagger ]]"
  apply = "go get -u github.com/grpc-ecosystem/grpc-gateway/protoc-gen-swagger"
  depends = ["task.gopath"]
}

[BrianHicks]

Yeah, gRPC requires Protocol Buffers 3.x.

[ryane]

my main problem was the protoc binary. once that was updated, the other golang dependencies needed rebuilt. In my troubleshooting, I ended up building protoc from source but it may not have been necessary - the pre-built binary might have been sufficient.