make json default protocol

init.go

diff --git a/init.go b/init.go
index 88d8274..0b3d8c8 100644
--- a/init.go
+++ b/init.go
@@ -3,8 +3,9 @@
 import (
 	"encoding/json"
 	"fmt"
-	"github.com/30x/apid"
 	"os"
+
+	"github.com/30x/apid"
 )
 
 const (
@@ -50,6 +51,7 @@
 
 func initDefaults() {
 	config.SetDefault(configPollInterval, 120)
+	config.SetDefault(configSnapshotProtocol, "json")
 	name, errh := os.Hostname()
 	if (errh != nil) && (len(config.GetString(configName)) == 0) {
 		log.Errorf("Not able to get hostname for kernel. Please set '%s' property in config", configName)
@@ -87,6 +89,10 @@
 			return pluginData, fmt.Errorf("Missing required config value: %s", key)
 		}
 	}
+	proto := config.GetString(configSnapshotProtocol)
+	if proto != "json" && proto != "proto" {
+		return pluginData, fmt.Errorf("Illegal value for %s. Must be: 'json' or 'proto'", configSnapshotProtocol)
+	}
 
 	// set up default database
 	db, err := data.DB()