multiple changes

- add cmd flags:
  - `-z` to activate authoritative zone
  - `-s` to activate dns sinkhole
- add example zone file

cmd/root.go

@@ -9,6 +9,8 @@ import (
 	"github.com/spf13/cobra"
 )
 
+var Verbose bool
+
 // rootCmd represents the base command when called without any subcommands
 var rootCmd = &cobra.Command{
 	Use:   "mercury",
@@ -40,6 +42,8 @@ func Execute() {
 }
 
 func init() {
+	verbose := os.Getenv("VERBOSE") != ""
+	rootCmd.PersistentFlags().BoolVarP(&Verbose, "verbose", "v", verbose, "verbose output")
 	// Here you will define your flags and configuration settings.
 	// Cobra supports persistent flags, which, if defined here,
 	// will be global for your application.

cmd/serve.go

@@ -15,6 +15,36 @@ import (
 	"gopkg.in/yaml.v2"
 )
 
+// Logln is a wrapper around log.Println that only prints if Verbose is true
+func Logln(a ...any) {
+	if Verbose {
+		log.Println(a...)
+	}
+}
+
+// Logf is a wrapper around log.Printf that only prints if Verbose is true
+func Logf(format string, a ...any) {
+	if Verbose {
+		log.Printf(format, a...)
+	}
+}
+
+// Printf is a wrapper around fmt.Printf that only prints if Verbose is true
+func Printf(format string, a ...any) (n int, err error) {
+	if Verbose {
+		return fmt.Printf(format, a...)
+	}
+	return 0, nil
+}
+
+// Println is a wrapper around fmt.Println that only prints if Verbose is true
+func Println(a ...any) (n int, err error) {
+	if Verbose {
+		return fmt.Println(a...)
+	}
+	return 0, nil
+}
+
 // DNS header size
 const BUFFER_SIZE = 2048
 
@@ -43,7 +73,7 @@ func loadZones() {
 		name := zone.Origin
 		zones[name] = zone
 	}
-	fmt.Printf("%+v\n", zones)
+	Printf("%+v\n", zones)
 }
 
 type Server struct {
@@ -73,8 +103,8 @@ func (s *Server) Run() {
 		if err != nil {
 			log.Fatal(err)
 		}
-		log.Println("Received", n, "bytes")
-		log.Println("from: ", remoteAddr)
+		Logln("Received", n, "bytes")
+		Logln("from: ", remoteAddr)
 		go s.handle(conn, remoteAddr, buffer[:n])
 	}
 }
@@ -92,18 +122,30 @@ func (s *Server) handle(conn *net.UDPConn, remoteAddr *net.UDPAddr, data []byte)
 	conn.WriteToUDP(res, remoteAddr)
 }
 
+var (
+	Zone     bool
+	Sinkhole bool
+	Source   string
+)
+
 // serveCmd represents the serve command
 var serveCmd = &cobra.Command{
 	Use:   "serve",
-	Short: "serve a dns queries",
+	Short: "serve dns queries",
 	Long: `Mercury is a lightweight DNS server that provides DNS resolution for a given set of zones.
 This server is designed to be used as as recursive resolver and a sinkhole, blocking unwanted DNS requests.`,
+
 	Run: func(cmd *cobra.Command, args []string) {
 		fmt.Println("serve called")
+		fmt.Println(Zone)
 		address := "0.0.0.0:53153"
-		loadZones()
-		// loadBlocklist()
-		blocklist["google.com."] = true
+		if Zone {
+			loadZones()
+		}
+		if Sinkhole {
+			// loadBlocklist()
+			blocklist["google.com."] = true
+		}
 		server := NewServer(
 			address,
 		)
@@ -112,6 +154,11 @@ This server is designed to be used as as recursive resolver and a sinkhole, bloc
 }
 
 func init() {
+	zone := os.Getenv("ZONE") != ""
+	sinkhole := os.Getenv("SINKHOLE") != ""
+	rootCmd.PersistentFlags().BoolVarP(&Zone, "zone", "z", zone, "authoritative zone")
+	rootCmd.PersistentFlags().BoolVarP(&Sinkhole, "sinkhole", "s", sinkhole, "dns sinkhole")
+
 	rootCmd.AddCommand(serveCmd)
 
 	// Here you will define your flags and configuration settings.

zones/bernoussama.com.yml → zones/example.com.yml

@@ -1,16 +1,16 @@
-origin: bernoussama.com.
+origin: example.com.
 ttl: 3600
 soa:
-  mname: ns1.bernoussama.com.
-  rname: admin.bernoussama.com.
+  mname: ns1.example.com.
+  rname: admin.example.com.
   serial: 2024110400
   refresh: 3600
   retry: 600
   expire: 604800
   minimum: 86400
 ns:
-  - host: ns1.bernoussama.com.
-  - host: ns2.bernoussama.com.
+  - host: ns1.example.com.
+  - host: ns2.example.com.
 a:
   - name: "@"
     ttl: 5