timestamppb.timestamp cause "json: cannot unmarshal object into Go value of type string" after upgrade v4.6

[gzhhong]

Describe the bug

1. I use golang and upgrade go micro from v4.5 to v4.6
2. I expected that all of my integration test should pass
3. What happens instead? My logger print errors below: {\"id\":\"go.micro.client.codec\",\"code\":500,\"detail\":\"json: cannot unmarshal object into Go value of type string\",\"status\":\"Internal Server Error\"} In general it is said go.micro.client.codec has error json: cannot unmarshal object into Go value of type string.

How to reproduce the bug

My message structure in proto file

message Meeting {
    // @inject_tag: json:"start" validate:"required"
    google.protobuf.Timestamp start = 1;
}

The golang structure created by protoc

type Meeting struct {
    state         protoimpl.MessageState
    sizeCache     protoimpl.SizeCache
    unknownFields protoimpl.UnknownFields

    // @inject_tag: json:"start" validate:"required"
    Start *timestamppb.Timestamp `protobuf:"bytes,1,opt,name=start,proto3" json:"start" validate:"required"`
}

When I assign value to meeting.Start, the code like:

    meeting.Start = timestamp.New(model.Start) // timestamp imported from "google.golang.org/protobuf/types/known/timestamppb"

There is no such value if I continue using go micro v4.5. I am using libprotoc 3.21.6 and protoc-gen-go v1.27.1

Go Version output:

go version go1.17.13 darwin/amd64

The go env output:

GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/zhihong/Library/Caches/go-build"
GOENV="/Users/zhihong/Library/Application Support/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GOMODCACHE="/Users/zhihong/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/Users/zhihong/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
GOVCS=""
GOVERSION="go1.17.13"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/dev/null"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -arch x86_64 -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/r7/f018pp653m3_fw0xv9jx_tgh0000gn/T/go-build2635807831=/tmp/go-build -gno-record-gcc-switches -fno-common"

Any suggestions welcomed, thanks,

James

[Davincible]

Thanks for reporting this! We should definitely look into this. Are there any tests, non specific to your system that you could provide that we could test with?

[jochumdev]

Hey @gzhhong / James,

just switch the clients DefaultContentType to "application/proto". I would as well switch server AND client to gRPC.

Let me know when you need help.

Kind Regards, René

[gzhhong]

@Davincible , Hello David, I upload a test project at https://github.com/gzhhong/test-grpc. I hope I made it clear in the readme and the code. @jochumdev , Hello Rene, could you please help to correct my sample code if possible?

Thanks both of you.

James

[Davincible]

@gzhhong hmm the request is never actually reaching the server on the second one.. interesting. This is gonna take some debugging.

Thanks for the example!

[tttao7]

Hey @gzhhong / James,

just switch the clients DefaultContentType to "application/proto". I would as well switch server AND client to gRPC.

Let me know when you need help.

Kind Regards, René

Hello @jochumdev / René ,

How to set DefaultContentType to "application/proto", can you give an example, thank you very much.

It's not okay to write like this

client.DefaultContentType = "application/protobuf"

Then I wrote it like this, and it always feels weird.

client.DefaultContentType = "application/protobuf"
client.DefaultClient = client.NewClient(client.ContentType(client.DefaultContentType))

Thank you !

[jochumdev]

Hi @tttao7 ,

I recommend something like (untested):

package main

import (
    "go-micro.dev/v4"
    grpcClient "github.com/go-micro/plugins/v4/client/grpc"
    grpcServer "github.com/go-micro/plugins/v4/server/grpc"
)

func main() {
    service := micro.NewService(
        micro.Name("greeter"),
        micro.Server(grpcServer.NewServer()),
        micro.Client(grpcClient.NewClient(client.ContentType("application/protobuf"))),
    )
}

Switching Server & Client to grpc will boost your application a lot AND it will work with protobuf.