Method TestGRPCLB_Basic

balancer/grpclb/grpclb_test.go:415–468

TestGRPCLB_Basic tests the basic case of a channel being configured with grpclb as the load balancing policy.

(t *testing.T)

// TestGRPCLB_Basic tests the basic case of a channel being configured with
// grpclb as the load balancing policy.
func (s) TestGRPCLB_Basic(t *testing.T) {
	tss, cleanup, err := startBackendsAndRemoteLoadBalancer(t, 1, testUserAgent, nil)
	if err != nil {
		t.Fatalf("failed to create new load balancer: %v", err)
	}
	defer cleanup()

	// Push the test backend address to the remote balancer.
	tss.ls.sls <- &lbpb.ServerList{
		Servers: []*lbpb.Server{
			{
				IpAddress:        tss.beIPs[0].AsSlice(),
				Port:             int32(tss.bePorts[0]),
				LoadBalanceToken: lbToken,
			},
		},
	}

	// Configure the manual resolver with an initial state containing a service
	// config with grpclb as the load balancing policy and the remote balancer
	// address specified via attributes.
	r := manual.NewBuilderWithScheme("whatever")
	s := &grpclbstate.State{
		BalancerAddresses: []resolver.Address{
			{
				Addr:       tss.lbAddr,
				ServerName: lbServerName,
			},
		},
	}
	rs := grpclbstate.Set(resolver.State{ServiceConfig: internal.ParseServiceConfig.(func(string) *serviceconfig.ParseResult)(grpclbConfig)}, s)
	r.InitialState(rs)

	// Connect to the test backend.
	dopts := []grpc.DialOption{
		grpc.WithResolvers(r),
		grpc.WithTransportCredentials(&serverNameCheckCreds{}),
		grpc.WithContextDialer(fakeNameDialer),
		grpc.WithUserAgent(testUserAgent),
	}
	cc, err := grpc.NewClient(r.Scheme()+":///"+beServerName, dopts...)
	if err != nil {
		t.Fatalf("Failed to create a client for the backend %v", err)
	}
	defer cc.Close()

	// Make one successful RPC.
	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
	defer cancel()
	testC := testgrpc.NewTestServiceClient(cc)
	if _, err := testC.EmptyCall(ctx, &testpb.Empty{}); err != nil {
		t.Fatalf("%v.EmptyCall(_, _) = _, %v, want _, <nil>", testC, err)
	}
}

// TestGRPCLB_Weighted tests weighted roundrobin. The remote balancer is
// configured to send a response with duplicate backend addresses (to simulate