optimize ParseIP

Signed-off-by: helen <haitao.zhang@daocloud.io>

pkg/karmadactl/cmdinit/utils/ip.go

@@ -5,19 +5,14 @@ import (
 	"net"
 )
 
-//ParseIP parse an ip address and return whether it is a v4 or v6 ip address
+// ParseIP parses an IP address and returns whether it is a v4 or v6 IP address
 func ParseIP(s string) (net.IP, int, error) {
 	ip := net.ParseIP(s)
 	if ip == nil {
 		return nil, 0, fmt.Errorf("%s is not a valid ip address", s)
 	}
-	for i := 0; i < len(s); i++ {
-		switch s[i] {
-		case '.':
-			return ip, 4, nil
-		case ':':
-			return ip, 6, nil
-		}
+	if ip.To4() != nil {
+		return ip, 4, nil
 	}
-	return nil, 0, fmt.Errorf("%s is not a valid ip address", s)
+	return ip, 6, nil
 }