resolver_update_test.go

Documentation: google.golang.org/grpc/test

     1  /*
     2   *
     3   * Copyright 2022 gRPC authors.
     4   *
     5   * Licensed under the Apache License, Version 2.0 (the "License");
     6   * you may not use this file except in compliance with the License.
     7   * You may obtain a copy of the License at
     8   *
     9   *     http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the License for the specific language governing permissions and
    15   * limitations under the License.
    16   *
    17   */
    18  
    19  package test
    20  
    21  import (
    22  	"context"
    23  	"encoding/json"
    24  	"errors"
    25  	"fmt"
    26  	"strings"
    27  	"testing"
    28  
    29  	"github.com/google/go-cmp/cmp"
    30  	"google.golang.org/grpc"
    31  	"google.golang.org/grpc/balancer"
    32  	"google.golang.org/grpc/codes"
    33  	"google.golang.org/grpc/credentials/insecure"
    34  	"google.golang.org/grpc/internal"
    35  	"google.golang.org/grpc/internal/balancer/stub"
    36  	"google.golang.org/grpc/internal/stubserver"
    37  	"google.golang.org/grpc/internal/testutils"
    38  	"google.golang.org/grpc/resolver"
    39  	"google.golang.org/grpc/resolver/manual"
    40  	"google.golang.org/grpc/serviceconfig"
    41  	"google.golang.org/grpc/status"
    42  
    43  	testgrpc "google.golang.org/grpc/interop/grpc_testing"
    44  	testpb "google.golang.org/grpc/interop/grpc_testing"
    45  )
    46  
    47  // TestResolverUpdateDuringBuild_ServiceConfigParseError makes the
    48  // resolver.Builder call into the ClientConn, during the Build call, with a
    49  // service config parsing error.
    50  //
    51  // We use two separate mutexes in the code which make sure there is no data race
    52  // in this code path, and also that there is no deadlock.
    53  func (s) TestResolverUpdateDuringBuild_ServiceConfigParseError(t *testing.T) {
    54  	// Setting InitialState on the manual resolver makes it call into the
    55  	// ClientConn during the Build call.
    56  	r := manual.NewBuilderWithScheme("whatever")
    57  	r.InitialState(resolver.State{ServiceConfig: &serviceconfig.ParseResult{Err: errors.New("resolver build err")}})
    58  
    59  	cc, err := grpc.NewClient(r.Scheme()+":///test.server", grpc.WithTransportCredentials(insecure.NewCredentials()), grpc.WithResolvers(r))
    60  	if err != nil {
    61  		t.Fatalf("NewClient(_, _) = _, %v; want _, nil", err)
    62  	}
    63  	defer cc.Close()
    64  
    65  	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
    66  	defer cancel()
    67  	client := testgrpc.NewTestServiceClient(cc)
    68  	const wantMsg = "error parsing service config"
    69  	const wantCode = codes.Unavailable
    70  	if _, err := client.EmptyCall(ctx, &testpb.Empty{}); status.Code(err) != wantCode || !strings.Contains(status.Convert(err).Message(), wantMsg) {
    71  		t.Fatalf("EmptyCall RPC failed: %v; want code: %v, want message: %q", err, wantCode, wantMsg)
    72  	}
    73  }
    74  
    75  type fakeConfig struct {
    76  	serviceconfig.Config
    77  }
    78  
    79  // TestResolverUpdateDuringBuild_ServiceConfigInvalidTypeError makes the
    80  // resolver.Builder call into the ClientConn, during the Build call, with an
    81  // invalid service config type.
    82  //
    83  // We use two separate mutexes in the code which make sure there is no data race
    84  // in this code path, and also that there is no deadlock.
    85  func (s) TestResolverUpdateDuringBuild_ServiceConfigInvalidTypeError(t *testing.T) {
    86  	// Setting InitialState on the manual resolver makes it call into the
    87  	// ClientConn during the Build call.
    88  	r := manual.NewBuilderWithScheme("whatever")
    89  	r.InitialState(resolver.State{ServiceConfig: &serviceconfig.ParseResult{Config: fakeConfig{}}})
    90  
    91  	cc, err := grpc.NewClient(r.Scheme()+":///test.server", grpc.WithTransportCredentials(insecure.NewCredentials()), grpc.WithResolvers(r))
    92  	if err != nil {
    93  		t.Fatalf("NewClient(_, _) = _, %v; want _, nil", err)
    94  	}
    95  	defer cc.Close()
    96  
    97  	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
    98  	defer cancel()
    99  	client := testgrpc.NewTestServiceClient(cc)
   100  	const wantMsg = "illegal service config type"
   101  	const wantCode = codes.Unavailable
   102  	if _, err := client.EmptyCall(ctx, &testpb.Empty{}); status.Code(err) != wantCode || !strings.Contains(status.Convert(err).Message(), wantMsg) {
   103  		t.Fatalf("EmptyCall RPC failed: %v; want code: %v, want message: %q", err, wantCode, wantMsg)
   104  	}
   105  }
   106  
   107  // TestResolverUpdate_InvalidServiceConfigAsFirstUpdate makes the resolver send
   108  // an update with an invalid service config as its first update. This should
   109  // make the ClientConn apply the failing LB policy, and should result in RPC
   110  // errors indicating the failing service config.
   111  func (s) TestResolverUpdate_InvalidServiceConfigAsFirstUpdate(t *testing.T) {
   112  	r := manual.NewBuilderWithScheme("whatever")
   113  
   114  	cc, err := grpc.Dial(r.Scheme()+":///test.server", grpc.WithTransportCredentials(insecure.NewCredentials()), grpc.WithResolvers(r))
   115  	if err != nil {
   116  		t.Fatalf("Dial(_, _) = _, %v; want _, nil", err)
   117  	}
   118  	defer cc.Close()
   119  
   120  	scpr := r.CC.ParseServiceConfig("bad json service config")
   121  	r.UpdateState(resolver.State{ServiceConfig: scpr})
   122  
   123  	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
   124  	defer cancel()
   125  	client := testgrpc.NewTestServiceClient(cc)
   126  	const wantMsg = "error parsing service config"
   127  	const wantCode = codes.Unavailable
   128  	if _, err := client.EmptyCall(ctx, &testpb.Empty{}); status.Code(err) != wantCode || !strings.Contains(status.Convert(err).Message(), wantMsg) {
   129  		t.Fatalf("EmptyCall RPC failed: %v; want code: %v, want message: %q", err, wantCode, wantMsg)
   130  	}
   131  }
   132  
   133  func verifyClientConnStateUpdate(got, want balancer.ClientConnState) error {
   134  	if got, want := got.ResolverState.Addresses, want.ResolverState.Addresses; !cmp.Equal(got, want) {
   135  		return fmt.Errorf("update got unexpected addresses: %v, want %v", got, want)
   136  	}
   137  	if got, want := got.ResolverState.ServiceConfig.Config, want.ResolverState.ServiceConfig.Config; !internal.EqualServiceConfigForTesting(got, want) {
   138  		return fmt.Errorf("received unexpected service config: \ngot: %v \nwant: %v", got, want)
   139  	}
   140  	if got, want := got.BalancerConfig, want.BalancerConfig; !cmp.Equal(got, want) {
   141  		return fmt.Errorf("received unexpected balancer config: \ngot: %v \nwant: %v", cmp.Diff(nil, got), cmp.Diff(nil, want))
   142  	}
   143  	return nil
   144  }
   145  
   146  // TestResolverUpdate_InvalidServiceConfigAfterGoodUpdate tests the scenario
   147  // where the resolver sends an update with an invalid service config after
   148  // having sent a good update. This should result in the ClientConn discarding
   149  // the new invalid service config, and continuing to use the old good config.
   150  func (s) TestResolverUpdate_InvalidServiceConfigAfterGoodUpdate(t *testing.T) {
   151  	type wrappingBalancerConfig struct {
   152  		serviceconfig.LoadBalancingConfig
   153  		Config string `json:"config,omitempty"`
   154  	}
   155  
   156  	// Register a stub balancer which uses a "pick_first" balancer underneath and
   157  	// signals on a channel when it receives ClientConn updates.
   158  	ccUpdateCh := testutils.NewChannel()
   159  	stub.Register(t.Name(), stub.BalancerFuncs{
   160  		Init: func(bd *stub.BalancerData) {
   161  			pf := balancer.Get(grpc.PickFirstBalancerName)
   162  			bd.Data = pf.Build(bd.ClientConn, bd.BuildOptions)
   163  		},
   164  		ParseConfig: func(lbCfg json.RawMessage) (serviceconfig.LoadBalancingConfig, error) {
   165  			cfg := &wrappingBalancerConfig{}
   166  			if err := json.Unmarshal(lbCfg, cfg); err != nil {
   167  				return nil, err
   168  			}
   169  			return cfg, nil
   170  		},
   171  		UpdateClientConnState: func(bd *stub.BalancerData, ccs balancer.ClientConnState) error {
   172  			if _, ok := ccs.BalancerConfig.(*wrappingBalancerConfig); !ok {
   173  				return fmt.Errorf("received balancer config of unsupported type %T", ccs.BalancerConfig)
   174  			}
   175  			bal := bd.Data.(balancer.Balancer)
   176  			ccUpdateCh.Send(ccs)
   177  			ccs.BalancerConfig = nil
   178  			return bal.UpdateClientConnState(ccs)
   179  		},
   180  	})
   181  
   182  	// Start a backend exposing the test service.
   183  	backend := &stubserver.StubServer{
   184  		EmptyCallF: func(ctx context.Context, in *testpb.Empty) (*testpb.Empty, error) { return &testpb.Empty{}, nil },
   185  	}
   186  	if err := backend.StartServer(); err != nil {
   187  		t.Fatalf("Failed to start backend: %v", err)
   188  	}
   189  	t.Logf("Started TestService backend at: %q", backend.Address)
   190  	defer backend.Stop()
   191  
   192  	r := manual.NewBuilderWithScheme("whatever")
   193  
   194  	cc, err := grpc.Dial(r.Scheme()+":///test.server", grpc.WithTransportCredentials(insecure.NewCredentials()), grpc.WithResolvers(r))
   195  	if err != nil {
   196  		t.Fatalf("Dial(_, _) = _, %v; want _, nil", err)
   197  	}
   198  	defer cc.Close()
   199  
   200  	// Push a resolver update and verify that our balancer receives the update.
   201  	addrs := []resolver.Address{{Addr: backend.Address}}
   202  	const lbCfg = "wrapping balancer LB policy config"
   203  	goodSC := r.CC.ParseServiceConfig(fmt.Sprintf(`
   204  {
   205    "loadBalancingConfig": [
   206      {
   207        "%v": {
   208          "config": "%s"
   209        }
   210      }
   211    ]
   212  }`, t.Name(), lbCfg))
   213  	r.UpdateState(resolver.State{Addresses: addrs, ServiceConfig: goodSC})
   214  
   215  	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
   216  	defer cancel()
   217  	wantCCS := balancer.ClientConnState{
   218  		ResolverState: resolver.State{
   219  			Addresses:     addrs,
   220  			ServiceConfig: goodSC,
   221  		},
   222  		BalancerConfig: &wrappingBalancerConfig{Config: lbCfg},
   223  	}
   224  	ccs, err := ccUpdateCh.Receive(ctx)
   225  	if err != nil {
   226  		t.Fatalf("Timeout when waiting for ClientConnState update from grpc")
   227  	}
   228  	gotCCS := ccs.(balancer.ClientConnState)
   229  	if err := verifyClientConnStateUpdate(gotCCS, wantCCS); err != nil {
   230  		t.Fatal(err)
   231  	}
   232  
   233  	// Ensure RPCs are successful.
   234  	client := testgrpc.NewTestServiceClient(cc)
   235  	if _, err := client.EmptyCall(ctx, &testpb.Empty{}); err != nil {
   236  		t.Fatalf("EmptyCall RPC failed: %v", err)
   237  	}
   238  
   239  	// Push a bad resolver update and ensure that the update is propagated to our
   240  	// stub balancer. But since the pushed update contains an invalid service
   241  	// config, our balancer should continue to see the old loadBalancingConfig.
   242  	badSC := r.CC.ParseServiceConfig("bad json service config")
   243  	wantCCS.ResolverState.ServiceConfig = badSC
   244  	r.UpdateState(resolver.State{Addresses: addrs, ServiceConfig: badSC})
   245  	ccs, err = ccUpdateCh.Receive(ctx)
   246  	if err != nil {
   247  		t.Fatalf("Timeout when waiting for ClientConnState update from grpc")
   248  	}
   249  	gotCCS = ccs.(balancer.ClientConnState)
   250  	if err := verifyClientConnStateUpdate(gotCCS, wantCCS); err != nil {
   251  		t.Fatal(err)
   252  	}
   253  
   254  	// RPCs should continue to be successful since the ClientConn is using the old
   255  	// good service config.
   256  	if _, err := client.EmptyCall(ctx, &testpb.Empty{}); err != nil {
   257  		t.Fatalf("EmptyCall RPC failed: %v", err)
   258  	}
   259  }
   260
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