Added customizable GRPC-Zerolog output writer option (#5)

Fixed GRPC-Zerolog output writer to be customizable and default to global Zerolog instance.

README.md

@@ -31,9 +31,16 @@ import (
 )
 
 func main() {
+	// With global Zerolog logger.
 	grpc.NewServer(
 		zerolog.UnaryInterceptor(),
 	)
+
+	// With custom Zerolog instance.
+	log := zerolog.New(os.Stdout)
+	grpc.NewServer(
+		zerolog.UnaryInterceptorWithLogger(&log),
+	)
 }
 ```
 

unary_interceptor.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"time"
 
+	"github.com/rs/zerolog"
+	"github.com/rs/zerolog/log"
 	"google.golang.org/grpc"
 )
 
@@ -12,6 +14,10 @@ func UnaryInterceptor() grpc.ServerOption {
 	return grpc.UnaryInterceptor(NewUnaryServerInterceptor())
 }
 
+func UnaryInterceptorWithLogger(log *zerolog.Logger) grpc.ServerOption {
+	return grpc.UnaryInterceptor(NewUnaryServerInterceptorWithLogger(log))
+}
+
 // NewUnaryServerInterceptor that logs gRPC Requests using Zerolog.
 //	{
 //		ServiceField: "ExampleService",
@@ -35,6 +41,10 @@ func UnaryInterceptor() grpc.ServerOption {
 //		ZerologMessageField: "UnaryMessageDefault",
 //	}
 func NewUnaryServerInterceptor() grpc.UnaryServerInterceptor {
+	return NewUnaryServerInterceptorWithLogger(&log.Logger)
+}
+
+func NewUnaryServerInterceptorWithLogger(log *zerolog.Logger) grpc.UnaryServerInterceptor {
 	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
 		now := time.Now()
 		resp, err := handler(ctx, req)

unary_interceptor_test.go

@@ -13,6 +13,7 @@ import (
 type TestUnaryInterceptorSuite struct {
 	suite.Suite
 	out    *bytes.Buffer
+	log    zerolog.Logger
 	client *test.TestClient
 }
 
@@ -21,15 +22,17 @@ func TestUnaryServerInterceptor(t *testing.T) {
 }
 
 func (s *TestUnaryInterceptorSuite) SetupSuite() {
+	s.out = &bytes.Buffer{}
+	s.log = zerolog.New(s.out)
 	go func() {
-		test.StartServer(NewUnaryServerInterceptor())
+		test.StartServer(NewUnaryServerInterceptorWithLogger(&s.log))
 	}()
 	s.client = test.GetClient()
 }
 
 func (s *TestUnaryInterceptorSuite) SetupTest() {
 	s.out = &bytes.Buffer{}
-	log = zerolog.New(s.out)
+	s.log = zerolog.New(s.out)
 }
 
 func TestUnaryInterceptor(t *testing.T) {

util.go

@@ -62,7 +62,6 @@ var (
 	DetailsField = "details"
 	// UnaryMessageDefault of logging messages from unary.
 	UnaryMessageDefault = "unary"
-	log                 = zerolog.Logger{}
 )
 
 // LogIncomingCall of gRPC method.