snapshot of https://github.com/grpc/grpc-go.git (master, 2026-09-15; blobs > 131072B omitted)

test/resolver_update_test.go

@@ -0,0 +1,263 @@
+/*
+ *
+ * Copyright 2022 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package test
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"strings"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/balancer/pickfirst"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/credentials/insecure"
+	"google.golang.org/grpc/internal"
+	"google.golang.org/grpc/internal/balancer/stub"
+	"google.golang.org/grpc/internal/stubserver"
+	"google.golang.org/grpc/internal/testutils"
+	"google.golang.org/grpc/resolver"
+	"google.golang.org/grpc/resolver/manual"
+	"google.golang.org/grpc/serviceconfig"
+	"google.golang.org/grpc/status"
+
+	testgrpc "google.golang.org/grpc/interop/grpc_testing"
+	testpb "google.golang.org/grpc/interop/grpc_testing"
+)
+
+// TestResolverUpdateDuringBuild_ServiceConfigParseError makes the
+// resolver.Builder call into the ClientConn, during the Build call, with a
+// service config parsing error.
+//
+// We use two separate mutexes in the code which make sure there is no data race
+// in this code path, and also that there is no deadlock.
+func (s) TestResolverUpdateDuringBuild_ServiceConfigParseError(t *testing.T) {
+	// Setting InitialState on the manual resolver makes it call into the
+	// ClientConn during the Build call.
+	r := manual.NewBuilderWithScheme("whatever")
+	r.InitialState(resolver.State{ServiceConfig: &serviceconfig.ParseResult{Err: errors.New("resolver build err")}})
+
+	cc, err := grpc.NewClient(r.Scheme()+":///test.server", grpc.WithTransportCredentials(insecure.NewCredentials()), grpc.WithResolvers(r))
+	if err != nil {
+		t.Fatalf("NewClient(_, _) = _, %v; want _, nil", err)
+	}
+	defer cc.Close()
+
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
+	defer cancel()
+	client := testgrpc.NewTestServiceClient(cc)
+	const wantMsg = "error parsing service config"
+	const wantCode = codes.Unavailable
+	if _, err := client.EmptyCall(ctx, &testpb.Empty{}); status.Code(err) != wantCode || !strings.Contains(status.Convert(err).Message(), wantMsg) {
+		t.Fatalf("EmptyCall RPC failed: %v; want code: %v, want message: %q", err, wantCode, wantMsg)
+	}
+}
+
+type fakeConfig struct {
+	serviceconfig.Config
+}
+
+// TestResolverUpdateDuringBuild_ServiceConfigInvalidTypeError makes the
+// resolver.Builder call into the ClientConn, during the Build call, with an
+// invalid service config type.
+//
+// We use two separate mutexes in the code which make sure there is no data race
+// in this code path, and also that there is no deadlock.
+func (s) TestResolverUpdateDuringBuild_ServiceConfigInvalidTypeError(t *testing.T) {
+	// Setting InitialState on the manual resolver makes it call into the
+	// ClientConn during the Build call.
+	r := manual.NewBuilderWithScheme("whatever")
+	r.InitialState(resolver.State{ServiceConfig: &serviceconfig.ParseResult{Config: fakeConfig{}}})
+
+	cc, err := grpc.NewClient(r.Scheme()+":///test.server", grpc.WithTransportCredentials(insecure.NewCredentials()), grpc.WithResolvers(r))
+	if err != nil {
+		t.Fatalf("NewClient(_, _) = _, %v; want _, nil", err)
+	}
+	defer cc.Close()
+
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
+	defer cancel()
+	client := testgrpc.NewTestServiceClient(cc)
+	const wantMsg = "illegal service config type"
+	const wantCode = codes.Unavailable
+	if _, err := client.EmptyCall(ctx, &testpb.Empty{}); status.Code(err) != wantCode || !strings.Contains(status.Convert(err).Message(), wantMsg) {
+		t.Fatalf("EmptyCall RPC failed: %v; want code: %v, want message: %q", err, wantCode, wantMsg)
+	}
+}
+
+// TestResolverUpdate_InvalidServiceConfigAsFirstUpdate makes the resolver send
+// an update with an invalid service config as its first update. This should
+// make the ClientConn apply the failing LB policy, and should result in RPC
+// errors indicating the failing service config.
+func (s) TestResolverUpdate_InvalidServiceConfigAsFirstUpdate(t *testing.T) {
+	r := manual.NewBuilderWithScheme("whatever")
+
+	cc, err := grpc.NewClient(r.Scheme()+":///test.server", grpc.WithTransportCredentials(insecure.NewCredentials()), grpc.WithResolvers(r))
+	if err != nil {
+		t.Fatalf("NewClient(_, _) = _, %v; want _, nil", err)
+	}
+	cc.Connect()
+	defer cc.Close()
+
+	scpr := r.CC().ParseServiceConfig("bad json service config")
+	r.UpdateState(resolver.State{ServiceConfig: scpr})
+
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
+	defer cancel()
+	client := testgrpc.NewTestServiceClient(cc)
+	const wantMsg = "error parsing service config"
+	const wantCode = codes.Unavailable
+	if _, err := client.EmptyCall(ctx, &testpb.Empty{}); status.Code(err) != wantCode || !strings.Contains(status.Convert(err).Message(), wantMsg) {
+		t.Fatalf("EmptyCall RPC failed: %v; want code: %v, want message: %q", err, wantCode, wantMsg)
+	}
+}
+
+func verifyClientConnStateUpdate(got, want balancer.ClientConnState) error {
+	if got, want := got.ResolverState.Addresses, want.ResolverState.Addresses; !cmp.Equal(got, want) {
+		return fmt.Errorf("update got unexpected addresses: %v, want %v", got, want)
+	}
+	if got, want := got.ResolverState.ServiceConfig.Config, want.ResolverState.ServiceConfig.Config; !internal.EqualServiceConfigForTesting(got, want) {
+		return fmt.Errorf("received unexpected service config: \ngot: %v \nwant: %v", got, want)
+	}
+	if got, want := got.BalancerConfig, want.BalancerConfig; !cmp.Equal(got, want) {
+		return fmt.Errorf("received unexpected balancer config: \ngot: %v \nwant: %v", cmp.Diff(nil, got), cmp.Diff(nil, want))
+	}
+	return nil
+}
+
+// TestResolverUpdate_InvalidServiceConfigAfterGoodUpdate tests the scenario
+// where the resolver sends an update with an invalid service config after
+// having sent a good update. This should result in the ClientConn discarding
+// the new invalid service config, and continuing to use the old good config.
+func (s) TestResolverUpdate_InvalidServiceConfigAfterGoodUpdate(t *testing.T) {
+	type wrappingBalancerConfig struct {
+		serviceconfig.LoadBalancingConfig
+		Config string `json:"config,omitempty"`
+	}
+
+	// Register a stub balancer which uses a "pick_first" balancer underneath and
+	// signals on a channel when it receives ClientConn updates.
+	ccUpdateCh := testutils.NewChannel()
+	stub.Register(t.Name(), stub.BalancerFuncs{
+		Init: func(bd *stub.BalancerData) {
+			pf := balancer.Get(pickfirst.Name)
+			bd.ChildBalancer = pf.Build(bd.ClientConn, bd.BuildOptions)
+		},
+		Close: func(bd *stub.BalancerData) {
+			bd.ChildBalancer.Close()
+		},
+		ParseConfig: func(lbCfg json.RawMessage) (serviceconfig.LoadBalancingConfig, error) {
+			cfg := &wrappingBalancerConfig{}
+			if err := json.Unmarshal(lbCfg, cfg); err != nil {
+				return nil, err
+			}
+			return cfg, nil
+		},
+		UpdateClientConnState: func(bd *stub.BalancerData, ccs balancer.ClientConnState) error {
+			if _, ok := ccs.BalancerConfig.(*wrappingBalancerConfig); !ok {
+				return fmt.Errorf("received balancer config of unsupported type %T", ccs.BalancerConfig)
+			}
+			ccUpdateCh.Send(ccs)
+			ccs.BalancerConfig = nil
+			return bd.ChildBalancer.UpdateClientConnState(ccs)
+		},
+	})
+
+	// Start a backend exposing the test service.
+	backend := &stubserver.StubServer{
+		EmptyCallF: func(context.Context, *testpb.Empty) (*testpb.Empty, error) { return &testpb.Empty{}, nil },
+	}
+	if err := backend.StartServer(); err != nil {
+		t.Fatalf("Failed to start backend: %v", err)
+	}
+	t.Logf("Started TestService backend at: %q", backend.Address)
+	defer backend.Stop()
+
+	r := manual.NewBuilderWithScheme("whatever")
+
+	cc, err := grpc.NewClient(r.Scheme()+":///test.server", grpc.WithTransportCredentials(insecure.NewCredentials()), grpc.WithResolvers(r))
+	if err != nil {
+		t.Fatalf("NewClient(_, _) = _, %v; want _, nil", err)
+	}
+	defer cc.Close()
+	cc.Connect()
+	// Push a resolver update and verify that our balancer receives the update.
+	addrs := []resolver.Address{{Addr: backend.Address}}
+	const lbCfg = "wrapping balancer LB policy config"
+	goodSC := r.CC().ParseServiceConfig(fmt.Sprintf(`
+{
+  "loadBalancingConfig": [
+    {
+      "%v": {
+        "config": "%s"
+      }
+    }
+  ]
+}`, t.Name(), lbCfg))
+	r.UpdateState(resolver.State{Addresses: addrs, ServiceConfig: goodSC})
+
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
+	defer cancel()
+	wantCCS := balancer.ClientConnState{
+		ResolverState: resolver.State{
+			Addresses:     addrs,
+			ServiceConfig: goodSC,
+		},
+		BalancerConfig: &wrappingBalancerConfig{Config: lbCfg},
+	}
+	ccs, err := ccUpdateCh.Receive(ctx)
+	if err != nil {
+		t.Fatalf("Timeout when waiting for ClientConnState update from grpc")
+	}
+	gotCCS := ccs.(balancer.ClientConnState)
+	if err := verifyClientConnStateUpdate(gotCCS, wantCCS); err != nil {
+		t.Fatal(err)
+	}
+
+	// Ensure RPCs are successful.
+	client := testgrpc.NewTestServiceClient(cc)
+	if _, err := client.EmptyCall(ctx, &testpb.Empty{}); err != nil {
+		t.Fatalf("EmptyCall RPC failed: %v", err)
+	}
+
+	// Push a bad resolver update and ensure that the update is propagated to our
+	// stub balancer. But since the pushed update contains an invalid service
+	// config, our balancer should continue to see the old loadBalancingConfig.
+	badSC := r.CC().ParseServiceConfig("bad json service config")
+	wantCCS.ResolverState.ServiceConfig = badSC
+	r.UpdateState(resolver.State{Addresses: addrs, ServiceConfig: badSC})
+	ccs, err = ccUpdateCh.Receive(ctx)
+	if err != nil {
+		t.Fatalf("Timeout when waiting for ClientConnState update from grpc")
+	}
+	gotCCS = ccs.(balancer.ClientConnState)
+	if err := verifyClientConnStateUpdate(gotCCS, wantCCS); err != nil {
+		t.Fatal(err)
+	}
+
+	// RPCs should continue to be successful since the ClientConn is using the old
+	// good service config.
+	if _, err := client.EmptyCall(ctx, &testpb.Empty{}); err != nil {
+		t.Fatalf("EmptyCall RPC failed: %v", err)
+	}
+}