fix: bug of skipping kubedns checking

cmd/root.go

@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"encoding/json"
 	"fmt"
 	"os"
 
@@ -24,13 +25,20 @@ var Opts = struct {
 }{}
 
 func init() {
+
 	RootCmd.PersistentFlags().StringVarP(&Opts.Cidr, "cidr", "c", os.Getenv("KUBERNETES_SERVICE_HOST")+"/16", "cidr like: 192.168.0.1/16")
+
 	RootCmd.PersistentFlags().StringVarP(&Opts.DnsServer, "dns-server", "d", "", "dns server")
 	RootCmd.PersistentFlags().IntVarP(&pkg.DnsTimeout, "dns-timeout", "i", 2, "dns timeout")
+
 	RootCmd.PersistentFlags().StringSliceVarP(&Opts.SvcDomains, "svc-domains", "s", []string{}, "service domains, like: kubernetes.default,etcd.default don't add zone like svc.cluster.local")
+
 	RootCmd.PersistentFlags().StringVarP(&Opts.Zone, "zone", "z", "cluster.local", "zone")
+
 	RootCmd.PersistentFlags().StringVarP(&Opts.OutputFile, "output-file", "o", "", "output file")
+
 	RootCmd.PersistentFlags().CountVarP(&Opts.Verbose, "verbose", "v", "log level (-v debug,-vv trace, info")
+
 	RootCmd.PersistentFlags().BoolVarP(&Opts.MultiThreadingMode, "thread", "t", false, "multi threading mode, work pair with -n")
 	RootCmd.PersistentFlags().IntVarP(&Opts.ThreadingNum, "thread-num", "n", 16, "threading num, default 16")
 
@@ -40,23 +48,33 @@ func init() {
 var RootCmd = &cobra.Command{
 	Use:   "k8spider",
 	Short: "k8spider is a tool to discover k8s services",
-	Long:  "k8spider is a tool to discover k8s services",
+	Long:  "k8spider is Powerful+Fast+Low Privilege Kubernetes service discovery tools via kubernetes DNS service. Currently supported service ip-port BruteForcing / AXFR Domain Transfer Dump / Coredns WildCard Dump / Pod Verified IP discovery\n\nTopics\n",
 	PersistentPreRun: func(cmd *cobra.Command, args []string) {
 		// Set Log Levels
 		SetLogLevel(Opts.Verbose)
 		// Set pkg global config
 		pkg.Zone = Opts.Zone
+
+		// debug print option data
+		opt, _ := json.MarshalIndent(Opts, "", "  ")
+		log.Tracef("Opts: %v", string(opt))
+
 		if Opts.DnsServer != "" {
 			pkg.NetResolver = pkg.WarpDnsServer(Opts.DnsServer)
 		}
+
 		// Check if current environment is a kubernetes cluster
-		// If the command is whereisdns, that DNS is not sure , so skip this check
+		// If the command is whereisdns, which means DNS is not sure , so skip this check!
 		// If SkipKubeDNSCheck is true, skip this check!
-		if Opts.SkipKubeDNSCheck == false || cmd.Use != "whereisdns" {
-			if pkg.CheckKubeDNS() {
-				log.Warn("current environment is not a kubernetes cluster")
-				os.Exit(1)
+		if Opts.SkipKubeDNSCheck == false {
+			if cmd.Use != "whereisdns" {
+				if !pkg.CheckKubeDNS() {
+					log.Warn("current environment is not a kubernetes cluster")
+					os.Exit(1)
+				}
 			}
+		} else {
+			log.Tracef("kubernetes environment checking bypassed")
 		}
 	},
 	Run: func(cmd *cobra.Command, args []string) {