[3.4] embed: fix nil pointer dereference when stopServer

embed/etcd.go

@@ -424,18 +424,20 @@ func (e *Etcd) Close() {
 }
 
 func stopServers(ctx context.Context, ss *servers) {
-	shutdownNow := func() {
-		// first, close the http.Server
+	// first, close the http.Server
+	if ss.http != nil {
 		ss.http.Shutdown(ctx)
-		// then close grpc.Server; cancels all active RPCs
-		ss.grpc.Stop()
+	}
+
+	if ss.grpc == nil {
+		return
 	}
 
 	// do not grpc.Server.GracefulStop with TLS enabled etcd server
 	// See https://github.com/grpc/grpc-go/issues/1384#issuecomment-317124531
 	// and https://github.com/etcd-io/etcd/issues/8916
 	if ss.secure && ss.http != nil {
-		shutdownNow()
+		ss.grpc.Stop()
 		return
 	}
 
@@ -453,7 +455,7 @@ func stopServers(ctx context.Context, ss *servers) {
 	case <-ctx.Done():
 		// took too long, manually close open transports
 		// e.g. watch streams
-		shutdownNow()
+		ss.grpc.Stop()
 
 		// concurrent GracefulStop should be interrupted
 		<-ch

tests/e2e/cluster_test.go

@@ -133,6 +133,8 @@ type etcdProcessClusterConfig struct {
 	WatchProcessNotifyInterval time.Duration
 
 	debug bool
+
+	stopSignal os.Signal
 }
 
 // newEtcdProcessCluster launches a new cluster from etcd processes, returning
@@ -151,12 +153,20 @@ func newEtcdProcessCluster(cfg *etcdProcessClusterConfig) (*etcdProcessCluster,
 			epc.Close()
 			return nil, err
 		}
+
 		epc.procs[i] = proc
 	}
 
 	if err := epc.Start(); err != nil {
 		return nil, err
 	}
+
+	// overwrite the default signal
+	if cfg.stopSignal != nil {
+		for _, proc := range epc.procs {
+			proc.WithStopSignal(cfg.stopSignal)
+		}
+	}
 	return epc, nil
 }
 

tests/e2e/cmux_test.go

@@ -21,6 +21,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"syscall"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -63,10 +64,19 @@ func TestConnectionMultiplexing(t *testing.T) {
 	} {
 		t.Run(tc.name, func(t *testing.T) {
 			ctx := context.Background()
-			cfg := etcdProcessClusterConfig{clusterSize: 1, clientTLS: tc.serverTLS, enableV2: true, clientHttpSeparate: tc.separateHttpPort}
+			cfg := etcdProcessClusterConfig{
+				clusterSize:        1,
+				clientTLS:          tc.serverTLS,
+				enableV2:           true,
+				clientHttpSeparate: tc.separateHttpPort,
+				stopSignal:         syscall.SIGTERM, // check graceful stop
+			}
 			clus, err := newEtcdProcessCluster(&cfg)
 			require.NoError(t, err)
-			defer clus.Close()
+
+			defer func() {
+				require.NoError(t, clus.Close())
+			}()
 
 			var clientScenarios []clientConnType
 			switch tc.serverTLS {