From 36d8b394e171968f4ef563ee0e55a4c7213e4df0 Mon Sep 17 00:00:00 2001
From: Alexandre Blazart <traz+github@dinauz.org>
Date: Thu, 13 Sep 2018 21:18:56 +0200
Subject: [PATCH] Atomically write the json file

---
 mdns.go | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/mdns.go b/mdns.go
index 6e60d8e..b52a241 100644
--- a/mdns.go
+++ b/mdns.go
@@ -14,6 +14,7 @@
 package main
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
 	"flag"
@@ -21,7 +22,6 @@ import (
 	"hash/fnv"
 	"io/ioutil"
 	"log"
-	"os"
 	"sort"
 	"strings"
 	"sync"
@@ -30,6 +30,7 @@ import (
 	"github.com/prometheus/common/model"
 
 	"github.com/hashicorp/mdns"
+	"github.com/natefinch/atomic"
 )
 
 type TargetGroup struct {
@@ -102,12 +103,10 @@ func main() {
 			if *output == "-" {
 				fmt.Println(string(y))
 			} else {
-				file, err := os.Create(*output) // For read access.
-				if err != nil {
+				buf := bytes.NewBuffer(y)
+				if err := atomic.WriteFile(*output, buf); err != nil {
 					log.Fatal(err)
 				}
-				file.Write(y)
-				file.Close()
 			}
 		}
 	}()