add core/error/util files

pkg/utils/network.go

@@ -0,0 +1,62 @@
+package utils
+
+import (
+	"bytes"
+	"net"
+
+	"github.com/mayswind/lab/pkg/errs"
+)
+
+func GetLocalIPAddressesString() (string, error) {
+	localAddrs, err := GetLocalIPAddresses()
+
+	if err != nil {
+		return "", err
+	}
+
+	if len(localAddrs) < 1 {
+		return "", errs.ErrGettingLocalAddress
+	}
+
+	buff := &bytes.Buffer{}
+
+	for i := 0; i < len(localAddrs); i++ {
+		if i > 0 {
+			buff.WriteString(",")
+		}
+
+		buff.WriteString(localAddrs[i].String())
+	}
+
+	return string(buff.Bytes()), nil
+}
+
+func GetLocalIPAddresses() ([]net.IP, error) {
+	addrs, err := net.InterfaceAddrs()
+
+	if err != nil {
+		return nil, err
+	}
+
+	var localAddrs []net.IP
+
+	for _, addr := range addrs {
+		if ipnet, ok := addr.(*net.IPNet); ok {
+			if ipnet.IP.IsLoopback() {
+				continue
+			}
+
+			if ipnet.IP.IsLinkLocalUnicast() {
+				continue
+			}
+
+			ip := ipnet.IP.To16()
+
+			if ip != nil {
+				localAddrs = append(localAddrs, ip)
+			}
+		}
+	}
+
+	return localAddrs, nil
+}