openmetrics: forward server context (#434)

Author: Aliaksandr Mianzhynski

providers/openmetrics/reporter.go

@@ -69,14 +69,14 @@ type reportable struct {
 }
 
 func (rep *reportable) ServerReporter(ctx context.Context, _ interface{}, typ interceptors.GRPCType, service string, method string) (interceptors.Reporter, context.Context) {
-	return rep.reporter(rep.serverMetrics, nil, typ, service, method, KindServer)
+	return rep.reporter(ctx, rep.serverMetrics, nil, typ, service, method, KindServer)
 }
 
 func (rep *reportable) ClientReporter(ctx context.Context, _ interface{}, typ interceptors.GRPCType, service string, method string) (interceptors.Reporter, context.Context) {
-	return rep.reporter(nil, rep.clientMetrics, typ, service, method, KindClient)
+	return rep.reporter(ctx, nil, rep.clientMetrics, typ, service, method, KindClient)
 }
 
-func (rep *reportable) reporter(sm *ServerMetrics, cm *ClientMetrics, rpcType interceptors.GRPCType, service, method string, kind Kind) (interceptors.Reporter, context.Context) {
+func (rep *reportable) reporter(ctx context.Context, sm *ServerMetrics, cm *ClientMetrics, rpcType interceptors.GRPCType, service, method string, kind Kind) (interceptors.Reporter, context.Context) {
 	r := &reporter{
 		clientMetrics: cm,
 		serverMetrics: sm,
@@ -110,7 +110,5 @@ func (rep *reportable) reporter(sm *ServerMetrics, cm *ClientMetrics, rpcType in
 		}
 		r.serverMetrics.serverStartedCounter.WithLabelValues(string(r.typ), r.service, r.method).Inc()
 	}
-
-	// TODO: @yashrsharma44 - What should we use instead of the context.Background()?
-	return r, context.Background()
+	return r, ctx
 }

providers/openmetrics/server_test.go

@@ -6,6 +6,7 @@ package metrics
 import (
 	"bufio"
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"net"
@@ -242,6 +243,9 @@ func (s *testService) PingEmpty(ctx context.Context, _ *pb_testproto.PingEmptyRe
 
 func (s *testService) Ping(ctx context.Context, ping *pb_testproto.PingRequest) (*pb_testproto.PingResponse, error) {
 	// Send user trailers and headers.
+	if _, ok := grpc.Method(ctx); !ok {
+		return nil, errors.New("cannot retrieve method name")
+	}
 	return &pb_testproto.PingResponse{Value: ping.Value, Counter: 42}, nil
 }
 
@@ -251,6 +255,9 @@ func (s *testService) PingError(ctx context.Context, ping *pb_testproto.PingErro
 }
 
 func (s *testService) PingList(ping *pb_testproto.PingListRequest, stream pb_testproto.TestService_PingListServer) error {
+	if _, ok := grpc.Method(stream.Context()); !ok {
+		return errors.New("cannot retrieve method name")
+	}
 	if ping.ErrorCodeReturned != 0 {
 		return status.Error(codes.Code(ping.ErrorCodeReturned), "foobar")
 	}