custom_lb_test.go

Documentation: google.golang.org/grpc/interop/xds

     1  /*
     2   *
     3   * Copyright 2023 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 xds
    20  
    21  import (
    22  	"context"
    23  	"errors"
    24  	"fmt"
    25  	"testing"
    26  	"time"
    27  
    28  	"google.golang.org/grpc"
    29  	"google.golang.org/grpc/credentials/insecure"
    30  	"google.golang.org/grpc/internal"
    31  	"google.golang.org/grpc/internal/grpctest"
    32  	"google.golang.org/grpc/internal/stubserver"
    33  	"google.golang.org/grpc/internal/testutils"
    34  	testgrpc "google.golang.org/grpc/interop/grpc_testing"
    35  	testpb "google.golang.org/grpc/interop/grpc_testing"
    36  	"google.golang.org/grpc/metadata"
    37  	"google.golang.org/grpc/resolver"
    38  	"google.golang.org/grpc/resolver/manual"
    39  	"google.golang.org/grpc/serviceconfig"
    40  )
    41  
    42  var defaultTestTimeout = 5 * time.Second
    43  
    44  type s struct {
    45  	grpctest.Tester
    46  }
    47  
    48  func Test(t *testing.T) {
    49  	grpctest.RunSubTests(t, s{})
    50  }
    51  
    52  // TestCustomLB tests the Custom LB for the interop client. It configures the
    53  // custom lb as the top level Load Balancing policy of the channel, then asserts
    54  // it can successfully make an RPC and also that the rpc behavior the Custom LB
    55  // is configured with makes it's way to the server in metadata.
    56  func (s) TestCustomLB(t *testing.T) {
    57  	errCh := testutils.NewChannel()
    58  	// Setup a backend which verifies the expected rpc-behavior metadata is
    59  	// present in the request.
    60  	backend := &stubserver.StubServer{
    61  		UnaryCallF: func(ctx context.Context, in *testpb.SimpleRequest) (*testpb.SimpleResponse, error) {
    62  			md, ok := metadata.FromIncomingContext(ctx)
    63  			if !ok {
    64  				errCh.Send(errors.New("failed to receive metadata"))
    65  				return &testpb.SimpleResponse{}, nil
    66  			}
    67  			rpcBMD := md.Get("rpc-behavior")
    68  			if len(rpcBMD) != 1 {
    69  				errCh.Send(fmt.Errorf("received %d values for metadata key \"rpc-behavior\", want 1", len(rpcBMD)))
    70  				return &testpb.SimpleResponse{}, nil
    71  			}
    72  			wantVal := "error-code-0"
    73  			if rpcBMD[0] != wantVal {
    74  				errCh.Send(fmt.Errorf("metadata val for key \"rpc-behavior\": got val %v, want val %v", rpcBMD[0], wantVal))
    75  				return &testpb.SimpleResponse{}, nil
    76  			}
    77  			// Success.
    78  			errCh.Send(nil)
    79  			return &testpb.SimpleResponse{}, nil
    80  		},
    81  	}
    82  	if err := backend.StartServer(); err != nil {
    83  		t.Fatalf("Failed to start backend: %v", err)
    84  	}
    85  	t.Logf("Started good TestService backend at: %q", backend.Address)
    86  	defer backend.Stop()
    87  
    88  	lbCfgJSON := `{
    89    		"loadBalancingConfig": [
    90      		{
    91        			"test.RpcBehaviorLoadBalancer": {
    92  					"rpcBehavior": "error-code-0"
    93        		}
    94      	}
    95    	]
    96  	}`
    97  
    98  	sc := internal.ParseServiceConfig.(func(string) *serviceconfig.ParseResult)(lbCfgJSON)
    99  	mr := manual.NewBuilderWithScheme("customlb-e2e")
   100  	defer mr.Close()
   101  	mr.InitialState(resolver.State{
   102  		Addresses: []resolver.Address{
   103  			{Addr: backend.Address},
   104  		},
   105  		ServiceConfig: sc,
   106  	})
   107  
   108  	cc, err := grpc.NewClient(mr.Scheme()+":///", grpc.WithResolvers(mr), grpc.WithTransportCredentials(insecure.NewCredentials()))
   109  	if err != nil {
   110  		t.Fatalf("grpc.NewClient() failed: %v", err)
   111  	}
   112  	defer cc.Close()
   113  	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
   114  	defer cancel()
   115  	testServiceClient := testgrpc.NewTestServiceClient(cc)
   116  
   117  	// Make a Unary RPC. This RPC should be successful due to the round_robin
   118  	// leaf balancer. Also, the custom load balancer should inject the
   119  	// "rpc-behavior" string it is configured with into the metadata sent to
   120  	// server.
   121  	if _, err := testServiceClient.UnaryCall(ctx, &testpb.SimpleRequest{}); err != nil {
   122  		t.Fatalf("EmptyCall() failed: %v", err)
   123  	}
   124  
   125  	val, err := errCh.Receive(ctx)
   126  	if err != nil {
   127  		t.Fatalf("error receiving from errCh: %v", err)
   128  	}
   129  
   130  	// Should receive nil on the error channel which implies backend verified it
   131  	// correctly received the correct "rpc-behavior" metadata.
   132  	if err, ok := val.(error); ok {
   133  		t.Fatalf("error in backend verifications on metadata received: %v", err)
   134  	}
   135  }
   136
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