Start

go get google.golang.org/grpc/cmd/protoc-gen-go-grpc
go get google.golang.org/protobuf/cmd/protoc-gen-go

go install google.golang.org/grpc/cmd/protoc-gen-go-grpc
go install google.golang.org/protobuf/cmd/protoc-gen-go

Generate

protoc --go_out=. --go_opt=paths=source_relative \
  --go-grpc_out=. --go-grpc_opt=paths=source_relative \
  proto/service.proto

Reflection

package pkg

import "google.golang.org/grpc/reflection"

func foo() {
    reflection.Register(server)
}

grpcurl -plaintext localhost:10116 list

grpc.reflection.v1alpha.ServerReflection
signservice.SignService

grpcurl -plaintext localhost:10116 describe

grpc.reflection.v1alpha.ServerReflection is a service:
service ServerReflection {
  rpc ServerReflectionInfo ( stream .grpc.reflection.v1alpha.ServerReflectionRequest ) returns ( stream .grpc.reflection.v1alpha.ServerReflectionResponse );
}
signservice.SignService is a service:
service SignService {
  rpc Sign ( .signservice.Document ) returns ( .signservice.DocSign );
  rpc SignStream ( stream .signservice.Document ) returns ( stream .signservice.DocSign );
  rpc Verify ( .signservice.VerifyRequest ) returns ( .signservice.VerifyResponse );
  rpc VerifyStream ( stream .signservice.VerifyRequest ) returns ( stream .signservice.VerifyResponse );
}

Sign

Data must be base64 encoded.

grpcurl -plaintext -format json -d '{"data": "YXNkYXNkYXNkYXNkYXNk"}' localhost:10116 signservice.SignService.Sign

Possible output

{
  "sign": "REGt4dNPZYLaQEXXA/PKTxwFaMhIhTkfsvxyOMQVY0oqmFd7f/XBFG6aX3KvVkgOEh7UsndqZv9csdgDn6zqDg=="
}

Verify

grpcurl -plaintext -format json -d '{"data": "YXNkYXNkYXNkYXNkYXNk"}' localhost:10116 signservice.SignService.Sign

Possible output

{
  "sign": "qf5+VF/juwmFQRMLedRzljnadrKeOQXUN0/SOBSQ3Gb79pS1/uOzJPhLNU1i0gEtdU3DLSA1SsfLIPLuhDanBg=="
}

grpcurl -plaintext -format json -d \
'{"doc":{"data": "YXNkYXNkYXNkYXNkYXNk"}, "sign":{"sign": "qf5+VF/juwmFQRMLedRzljnadrKeOQXUN0/SOBSQ3Gb79pS1/uOzJPhLNU1i0gEtdU3DLSA1SsfLIPLuhDanBg=="}}' \
localhost:10116 signservice.SignService.Verify

Possible output

{
  "isOk": true
}

Bad signature

grpcurl -emit-defaults -plaintext -format json -d \
'{"doc":{"data": "YXNkYXNkYXNkYXNkYXNk"}, "sign":{"sign": "qf5+VF/juwmFQRMLedRzljnadrKeOQXUN0/SOBSQ3Gb79pS1/uOzJPhLNU1i0gEtdU3DLSA1SsfLIPLuhDanBg=="}}' \
localhost:10116 signservice.SignService.Verify

{
  "isOk": false
}

Benchmarks

Bench name	Loop count	ns/op
BenchmarkGrpcDocSignServer_Sign/size_17-16	29068	40537
BenchmarkGrpcDocSignServer_Sign/size_1024-16	28004	42641
BenchmarkGrpcDocSignServer_Sign/size_1024*1024-16	637	1861758
BenchmarkGrpcDocSignServer_Sign/size_nil-16	30822	39082
BenchmarkGrpcDocSignServer_SignUnary-16	596	1992559
BenchmarkGrpcDocSignServer_SignBatch/size_0-16	79906	15165
BenchmarkGrpcDocSignServer_SignBatch/size_17-16	29290	41040
BenchmarkGrpcDocSignServer_SignBatch/size_6*17-16	8178	147086
BenchmarkGrpcDocSignServer_SignBatch/size_5*1024+17-16	7665	159833
BenchmarkGrpcDocSignServer_SignBatch/size_17+1024+1024*1024-16	621	1928025
BenchmarkGrpcDocSignServer_SignStream/size_none-16	964539764	1.243
BenchmarkGrpcDocSignServer_SignStream/size_17-16	41540	28521
BenchmarkGrpcDocSignServer_SignStream/size_4*17-16	10000	102939
BenchmarkGrpcDocSignServer_SignStream/size_3*1024+17-16	10000	109679
BenchmarkGrpcDocSignServer_SignStream/size_2010241024-16	31	35026141
BenchmarkGrpcDocSignServer_SignStream/size_1024*1024+1024+17-16	681	1749070

Platform:

• goos: darwin
• goarch: arm64
• cpu: Apple M1 Max

In bench.txt you can find raw results of a single run of the benchmark.

REST API

go install \
    github.com/grpc-ecosystem/grpc-gateway/v2/protoc-gen-grpc-gateway \
    github.com/grpc-ecosystem/grpc-gateway/v2/protoc-gen-openapiv2 \
    google.golang.org/protobuf/cmd/protoc-gen-go \
    google.golang.org/grpc/cmd/protoc-gen-go-grpc

protoc -I . --grpc-gateway_out . \
    --grpc-gateway_opt logtostderr=true \
    --grpc-gateway_opt paths=source_relative \
    --grpc-gateway_opt generate_unbound_methods=true \
    proto/service.proto

curl -H 'Authorization: jwt fgdfgdfgdgfdgfdgfdgfd' --data '{"data": "YXNkYXNkYXNkYXNkYXNk"}' localhost:8080/signservice.SignService/Sign                                                                                                                  

{"sign":"Jem/OJYUH6b0OseqsFCQA9zAhfBEPWpjUGMgO1BoQw2NkNj5Nb2MY6UkF9xPVNom7bb0E0fik9fEeNl/N4n7Bw=="}%

grpcurl -plaintext -H 'Authorization: jwt fgdfgdfgdgfdgfdgfdgfd' -format json -d '{"data": "YXNkYXNkYXNkYXNkYXNk"}' localhost:10116 signservice.SignService.Sign

{
  "sign": "Jem/OJYUH6b0OseqsFCQA9zAhfBEPWpjUGMgO1BoQw2NkNj5Nb2MY6UkF9xPVNom7bb0E0fik9fEeNl/N4n7Bw=="
}

Helpful Links

• https://learn.microsoft.com/en-us/aspnet/core/grpc/performance
• https://github.com/grpc-ecosystem/go-grpc-middleware
• https://github.com/grpc-ecosystem/grpc-gateway
• https://blog.logrocket.com/guide-to-grpc-gateway/
• https://protobuf.dev/programming-guides/encoding/
• https://protobuf.dev/programming-guides/dos-donts/
• https://learn.microsoft.com/en-us/dotnet/architecture/grpc-for-wcf-developers/streaming-versus-repeated