pkg/hostagent: Use Go's built-in DNS resolver in DialContextToGuestIP

Signed-off-by: Norio Nomura <norio.nomura@gmail.com>

Author: norio-nomura

pkg/hostagent/hostagent.go

@@ -999,7 +999,13 @@ func (a *HostAgent) DialContextToGuestIP(guestIP net.IP) func(ctx context.Contex
 		default:
 			return nil, fmt.Errorf("unsupported network %q", network)
 		}
-		d := net.Dialer{LocalAddr: sourceAddr}
+		d := net.Dialer{
+			LocalAddr: sourceAddr,
+			Resolver: &net.Resolver{
+				PreferGo:     true,
+				StrictErrors: true,
+			},
+		}
 		_, port, err := net.SplitHostPort(address)
 		if err != nil {
 			return nil, err