Use net.JoinHostPort and net.SplitHostPort for IPv6-safe host:port handling (#5836)

management/server/http/handlers/dns/nameservers_handler.go

@@ -3,7 +3,10 @@ package dns
 import (
 	"encoding/json"
 	"fmt"
+	"net"
 	"net/http"
+	"strconv"
+	"strings"
 
 	"github.com/gorilla/mux"
 	log "github.com/sirupsen/logrus"
@@ -201,7 +204,7 @@ func (h *nameserversHandler) getNameserverGroup(w http.ResponseWriter, r *http.R
 func toServerNSList(apiNSList []api.Nameserver) ([]nbdns.NameServer, error) {
 	var nsList []nbdns.NameServer
 	for _, apiNS := range apiNSList {
-		parsed, err := nbdns.ParseNameServerURL(fmt.Sprintf("%s://%s:%d", apiNS.NsType, apiNS.Ip, apiNS.Port))
+		parsed, err := nbdns.ParseNameServerURL(fmt.Sprintf("%s://%s", apiNS.NsType, net.JoinHostPort(strings.Trim(apiNS.Ip, "[]"), strconv.Itoa(apiNS.Port))))
 		if err != nil {
 			return nil, err
 		}

management/server/http/handlers/dns/nameservers_handler_test.go

@@ -233,3 +233,37 @@ func TestNameserversHandlers(t *testing.T) {
 		})
 	}
 }
+
+func TestToServerNSList_IPv6(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    []api.Nameserver
+		expectIP netip.Addr
+	}{
+		{
+			name: "IPv4",
+			input: []api.Nameserver{
+				{Ip: "1.1.1.1", NsType: "udp", Port: 53},
+			},
+			expectIP: netip.MustParseAddr("1.1.1.1"),
+		},
+		{
+			name: "IPv6",
+			input: []api.Nameserver{
+				{Ip: "2001:4860:4860::8888", NsType: "udp", Port: 53},
+			},
+			expectIP: netip.MustParseAddr("2001:4860:4860::8888"),
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			result, err := toServerNSList(tc.input)
+			assert.NoError(t, err)
+			if assert.Len(t, result, 1) {
+				assert.Equal(t, tc.expectIP, result[0].IP)
+				assert.Equal(t, 53, result[0].Port)
+			}
+		})
+	}
+}