Interceptor Chain

import (
	"context"
	"log"
	"time"

	"google.golang.org/grpc"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
)

func loggingInterceptor(
	ctx context.Context,
	req interface{},
	info *grpc.UnaryServerInfo,
	handler grpc.UnaryHandler,
) (interface{}, error) {
	start := time.Now()
	resp, err := handler(ctx, req)
	log.Printf("method=%s duration=%s err=%v", info.FullMethod, time.Since(start), err)
	return resp, err
}

func recoveryInterceptor(
	ctx context.Context,
	req interface{},
	info *grpc.UnaryServerInfo,
	handler grpc.UnaryHandler,
) (resp interface{}, err error) {
	defer func() {
		if r := recover(); r != nil {
			log.Printf("panic: %v", r)
			err = status.Errorf(codes.Internal, "internal error")
		}
	}()
	return handler(ctx, req)
}

func main() {
	srv := grpc.NewServer(
		grpc.ChainUnaryInterceptor(
			loggingInterceptor,
			recoveryInterceptor,
		),
	)
	// register services and serve...
}