improve: 使用标准项目结构

internal/pkg/dns/util/config.go

@@ -0,0 +1,9 @@
+package dnsUtil
+
+import (
+	"github.com/mitchellh/mapstructure"
+)
+
+func DecodeConfig(conf map[string]interface{}, output interface{}) error {
+	return mapstructure.Decode(conf, output)
+}

internal/pkg/dns/util/domain.go

@@ -0,0 +1,18 @@
+package dnsUtil
+
+import (
+	"errors"
+	"strings"
+)
+
+func DecodeDomain(domain string) (subStr string, rootDomain string, e error) {
+	t := strings.Split(domain, ".")
+	if len(t) == 1 {
+		return "", "", errors.New("域名不合法")
+	} else if len(t) == 2 {
+		return "@", domain, nil
+	}
+
+	l := len(t)
+	return strings.Join(t[:l-2], "."), strings.Join(t[l-2:l], "."), nil
+}