config_show should output pretty json

This commit changes the output of aptly config show to be pretty json
rather than YAML.

cmd/config_show.go

@@ -1,10 +1,8 @@
 package cmd
 
 import (
+	"encoding/json"
 	"fmt"
-	"reflect"
-	"strconv"
-	"strings"
 
 	"github.com/smira/commander"
 )
@@ -12,55 +10,19 @@ import (
 func aptlyConfigShow(cmd *commander.Command, args []string) error {
 
 	config := context.Config()
+	pretty_json, err := json.MarshalIndent(config, "", "    ")
 
-	config_to_string := toString(reflect.ValueOf(config).Elem())
-
-	if config_to_string == "" {
-		return fmt.Errorf("Error processing configuration")
+	if err != nil {
+		return fmt.Errorf("unable to parse the config file: %s", err)
 	}
 
+	config_to_string := string(pretty_json)
+
 	fmt.Println(config_to_string)
 
 	return nil
 }
 
-func toString(v reflect.Value) string {
-
-	switch v.Kind() {
-
-	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-		return strconv.FormatInt(v.Int(), 10)
-	case reflect.Bool:
-		return strconv.FormatBool(v.Bool())
-	case reflect.Slice:
-		var str_slice []string
-		for i := 0; i < v.Len(); i++ {
-			str_slice = append(str_slice, toString(v.Index(i)))
-		}
-		return strings.Join(str_slice, ", ")
-	case reflect.Struct:
-		var str_slice []string
-		typ := reflect.TypeOf(v.Interface())
-		for i := 0; i < typ.NumField(); i++ {
-			str_slice = append(str_slice, typ.Field(i).Name+": "+toString(v.Field(i)))
-		}
-		return strings.Join(str_slice, "\n")
-	case reflect.Map:
-		var str_slice []string
-		str_slice = append(str_slice, "")
-		for _, key := range v.MapKeys() {
-			str_slice = append(str_slice, "- "+toString(key)+":\n"+toString(v.MapIndex(key)))
-		}
-		return strings.Join(str_slice, "\n")
-	case reflect.String:
-		return v.String()
-	default:
-		return ""
-	}
-
-	return ""
-}
-
 func makeCmdConfigShow() *commander.Command {
 	cmd := &commander.Command{
 		Run:       aptlyConfigShow,