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

resolver_test.go

@@ -0,0 +1,197 @@
+/*
+ *
+ * Copyright 2023 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 grpc
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"google.golang.org/grpc/attributes"
+	"google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/credentials/insecure"
+	"google.golang.org/grpc/internal/balancer/stub"
+	"google.golang.org/grpc/resolver"
+	"google.golang.org/grpc/resolver/manual"
+)
+
+type wrapResolverBuilder struct {
+	resolver.Builder
+	scheme string
+}
+
+func (w *wrapResolverBuilder) Scheme() string {
+	return w.scheme
+}
+
+func init() {
+	resolver.Register(&wrapResolverBuilder{Builder: resolver.Get("passthrough"), scheme: "casetest"})
+	resolver.Register(&wrapResolverBuilder{Builder: resolver.Get("dns"), scheme: "caseTest"})
+}
+
+func (s) TestResolverCaseSensitivity(t *testing.T) {
+	// This should find the "casetest" resolver instead of the "caseTest"
+	// resolver, even though the latter was registered later.  "casetest" is
+	// "passthrough" and "caseTest" is "dns".  With "passthrough" the dialer
+	// should see the target's address directly, but "dns" would be converted
+	// into a loopback IP (v4 or v6) address.
+	target := "caseTest:///localhost:1234"
+	addrCh := make(chan string, 1)
+	customDialer := func(_ context.Context, addr string) (net.Conn, error) {
+		select {
+		case addrCh <- addr:
+		default:
+		}
+		return nil, fmt.Errorf("not dialing with custom dialer")
+	}
+
+	cc, err := NewClient(target, WithContextDialer(customDialer), WithTransportCredentials(insecure.NewCredentials()))
+	if err != nil {
+		t.Fatalf("Unexpected NewClient(%q) error: %v", target, err)
+	}
+	cc.Connect()
+	if got, want := <-addrCh, "localhost:1234"; got != want {
+		cc.Close()
+		t.Fatalf("Dialer got address %q; wanted %q", got, want)
+	}
+	cc.Close()
+
+	// Clear addrCh for future use.
+	select {
+	case <-addrCh:
+	default:
+	}
+
+	res := &wrapResolverBuilder{Builder: resolver.Get("dns"), scheme: "caseTest2"}
+	// This should not find the injected resolver due to the case not matching.
+	// This results in "passthrough" being used with the address as the whole
+	// target.
+	target = "caseTest2:///localhost:1234"
+	cc, err = NewClient(target, WithContextDialer(customDialer), withDefaultScheme("passthrough"), WithResolvers(res), WithTransportCredentials(insecure.NewCredentials()))
+	if err != nil {
+		t.Fatalf("Unexpected NewClient(%q) error: %v", target, err)
+	}
+	cc.Connect()
+	if got, want := <-addrCh, target; got != want {
+		cc.Close()
+		t.Fatalf("Dialer got address %q; wanted %q", got, want)
+	}
+	cc.Close()
+}
+
+// TestResolverAddressesToEndpoints ensures one Endpoint is created for each
+// entry in resolver.State.Addresses automatically.
+func (s) TestResolverAddressesToEndpoints(t *testing.T) {
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
+	defer cancel()
+
+	const scheme = "testresolveraddressestoendpoints"
+	r := manual.NewBuilderWithScheme(scheme)
+
+	stateCh := make(chan balancer.ClientConnState, 1)
+	bf := stub.BalancerFuncs{
+		UpdateClientConnState: func(_ *stub.BalancerData, ccs balancer.ClientConnState) error {
+			stateCh <- ccs
+			return nil
+		},
+	}
+	balancerName := "stub-balancer-" + scheme
+	stub.Register(balancerName, bf)
+
+	a1 := attributes.New("x", "y")
+	a2 := attributes.New("a", "b")
+	r.InitialState(resolver.State{Addresses: []resolver.Address{{Addr: "addr1", BalancerAttributes: a1}, {Addr: "addr2", BalancerAttributes: a2}}})
+
+	cc, err := NewClient(r.Scheme()+":///",
+		WithTransportCredentials(insecure.NewCredentials()),
+		WithResolvers(r),
+		WithDefaultServiceConfig(fmt.Sprintf(`{"loadBalancingConfig": [{"%s":{}}]}`, balancerName)))
+	if err != nil {
+		t.Fatalf("NewClient() failed: %v", err)
+	}
+	cc.Connect()
+	defer cc.Close()
+
+	select {
+	case got := <-stateCh:
+		want := []resolver.Endpoint{
+			{Addresses: []resolver.Address{{Addr: "addr1"}}, Attributes: a1},
+			{Addresses: []resolver.Address{{Addr: "addr2"}}, Attributes: a2},
+		}
+		if diff := cmp.Diff(got.ResolverState.Endpoints, want); diff != "" {
+			t.Errorf("Did not receive expected endpoints.  Diff (-got +want):\n%v", diff)
+		}
+	case <-ctx.Done():
+		t.Fatalf("timed out waiting for endpoints")
+	}
+}
+
+// Test ensures one Endpoint is created for each entry in
+// resolver.State.Addresses automatically. The test calls the deprecated
+// NewAddresses API to send a list of addresses to the channel.
+func (s) TestResolverAddressesToEndpointsUsingNewAddresses(t *testing.T) {
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
+	defer cancel()
+
+	const scheme = "testresolveraddressestoendpoints"
+	r := manual.NewBuilderWithScheme(scheme)
+
+	stateCh := make(chan balancer.ClientConnState, 1)
+	bf := stub.BalancerFuncs{
+		UpdateClientConnState: func(_ *stub.BalancerData, ccs balancer.ClientConnState) error {
+			stateCh <- ccs
+			return nil
+		},
+	}
+	balancerName := "stub-balancer-" + scheme
+	stub.Register(balancerName, bf)
+
+	a1 := attributes.New("x", "y")
+	a2 := attributes.New("a", "b")
+	addrs := []resolver.Address{
+		{Addr: "addr1", BalancerAttributes: a1},
+		{Addr: "addr2", BalancerAttributes: a2},
+	}
+
+	cc, err := NewClient(r.Scheme()+":///",
+		WithTransportCredentials(insecure.NewCredentials()),
+		WithResolvers(r),
+		WithDefaultServiceConfig(fmt.Sprintf(`{"loadBalancingConfig": [{"%s":{}}]}`, balancerName)))
+	if err != nil {
+		t.Fatalf("NewClient() failed: %v", err)
+	}
+	cc.Connect()
+	defer cc.Close()
+	r.CC().NewAddress(addrs)
+
+	select {
+	case got := <-stateCh:
+		want := []resolver.Endpoint{
+			{Addresses: []resolver.Address{{Addr: "addr1"}}, Attributes: a1},
+			{Addresses: []resolver.Address{{Addr: "addr2"}}, Attributes: a2},
+		}
+		if diff := cmp.Diff(got.ResolverState.Endpoints, want); diff != "" {
+			t.Errorf("Did not receive expected endpoints.  Diff (-got +want):\n%v", diff)
+		}
+	case <-ctx.Done():
+		t.Fatalf("timed out waiting for endpoints")
+	}
+}