encode contacts as hex to be friendly on RPC return

dht/contact.go

@@ -2,6 +2,7 @@ package dht
 
 import (
 	"bytes"
+	"encoding/json"
 	"net"
 	"sort"
 	"strconv"
@@ -41,6 +42,20 @@ func (c Contact) String() string {
 	return str
 }
 
+func (c Contact) MarshalJSON() ([]byte, error) {
+	return json.Marshal(&struct {
+		ID string
+		IP string
+		Port int
+		PeerPort int
+	}{
+		ID: c.ID.Hex(),
+		IP: c.IP.String(),
+		Port: c.Port,
+		PeerPort: c.PeerPort,
+	})
+}
+
 // MarshalCompact returns a compact byteslice representation of the contact
 // NOTE: The compact representation always uses the tcp PeerPort, not the udp Port. This is dumb, but that's how the python daemon does it
 func (c Contact) MarshalCompact() ([]byte, error) {