fix: etcd discovery mechanism on grpc with idle manager (#4589)

zrpc/resolver/internal/discovbuilder.go

@@ -38,9 +38,24 @@ func (b *discovBuilder) Build(target resolver.Target, cc resolver.ClientConn, _
 	sub.AddListener(update)
 	update()
 
-	return &nopResolver{cc: cc, closeFunc: func() { sub.Close() }}, nil
+	return &discovResolver{
+		cc:  cc,
+		sub: sub,
+	}, nil
 }
 
 func (b *discovBuilder) Scheme() string {
 	return DiscovScheme
 }
+
+type discovResolver struct {
+	cc  resolver.ClientConn
+	sub *discov.Subscriber
+}
+
+func (r *discovResolver) Close() {
+	r.sub.Close()
+}
+
+func (r *discovResolver) ResolveNow(_ resolver.ResolveNowOptions) {
+}

zrpc/resolver/internal/kubebuilder.go

@@ -28,6 +28,10 @@ type kubeResolver struct {
 	stopCh chan struct{}
 }
 
+func (r *kubeResolver) Close() {
+	close(r.stopCh)
+}
+
 func (r *kubeResolver) ResolveNow(_ resolver.ResolveNowOptions) {}
 
 func (r *kubeResolver) start() {
@@ -36,10 +40,6 @@ func (r *kubeResolver) start() {
 	})
 }
 
-func (r *kubeResolver) Close() {
-	close(r.stopCh)
-}
-
 type kubeBuilder struct{}
 
 func (b *kubeBuilder) Build(target resolver.Target, cc resolver.ClientConn,

zrpc/resolver/internal/resolver.go

@@ -37,14 +37,10 @@ func register() {
 }
 
 type nopResolver struct {
-	cc        resolver.ClientConn
-	closeFunc func()
+	cc resolver.ClientConn
 }
 
 func (r *nopResolver) Close() {
-	if r.closeFunc != nil {
-		r.closeFunc()
-	}
 }
 
 func (r *nopResolver) ResolveNow(_ resolver.ResolveNowOptions) {

zrpc/resolver/internal/resolver_test.go

@@ -1,7 +1,6 @@
 package internal
 
 import (
-	"github.com/zeromicro/go-zero/core/discov"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -19,20 +18,6 @@ func TestNopResolver(t *testing.T) {
 	})
 }
 
-func TestNopResolver_Close(t *testing.T) {
-	var isChanged bool
-	r := nopResolver{}
-	r.Close()
-	assert.False(t, isChanged)
-	r = nopResolver{
-		closeFunc: func() {
-			isChanged = true
-		},
-	}
-	r.Close()
-	assert.True(t, isChanged)
-}
-
 type mockedClientConn struct {
 	state resolver.State
 	err   error