A gRPC server in Go kit

Adding a gPRC server using Go kit is almost as easy as adding a JSON/HTTP server, like we did in the last section. In our generated code (in the pb folder), we were given the following pb.VaultServer type:

type VaultServer interface { 
  Hash(context.Context, *HashRequest)
    (*HashResponse, error) 
  Validate(context.Context, *ValidateRequest)
    (*ValidateResponse, error) 
} 

This type is very similar to our own Service interface, except that it takes in generated request and response classes rather than raw arguments.

We'll start by defining a type that will implement the preceding interface. Add the following code to a new file called server_grpc.go:

package vault 
import ( 
  "golang.org/x/net/context" 
  grpctransport "github.com/go-kit/kit/transport/grpc" 
) 
type grpcServer struct { 
  hash     grpctransport.Handler 
  validate grpctransport.Handler 
} 
func (s *grpcServer) Hash(ctx context.Context,
 r *pb.HashRequest) (*pb.HashResponse, error) { 
  _, resp...