From 7ddc71006ba78dcbe7c3a6e7cdd133f2d5602943 Mon Sep 17 00:00:00 2001
From: Eugene Bujak <hmage@hmage.net>
Date: Wed, 5 Dec 2018 15:36:18 +0300
Subject: [PATCH] stop DNS server properly when interrupted with ctrl+c,
SIGTERM, SIGHUP or SIGQUIT
---
app.go | 20 ++++++++++++++++----
coredns.go | 13 +++++++++++++
2 files changed, 29 insertions(+), 4 deletions(-)
diff --git a/app.go b/app.go
index f958c7b4..10469245 100644
--- a/app.go
+++ b/app.go
@@ -7,8 +7,10 @@ import (
"net"
"net/http"
"os"
+ "os/signal"
"path/filepath"
"strconv"
+ "syscall"
"time"
"github.com/gobuffalo/packr"
@@ -164,10 +166,13 @@ func main() {
}
}()
- // Eat all args so that coredns can start happily
- if len(os.Args) > 1 {
- os.Args = os.Args[:1]
- }
+ signal_channel := make(chan os.Signal)
+ signal.Notify(signal_channel, syscall.SIGINT, syscall.SIGTERM, syscall.SIGHUP, syscall.SIGQUIT)
+ go func() {
+ <-signal_channel
+ cleanup()
+ os.Exit(0)
+ }()
// Save the updated config
err := config.write()
@@ -192,6 +197,13 @@ func main() {
log.Fatal(http.ListenAndServe(address, nil))
}
+func cleanup() {
+ err := stopDNSServer()
+ if err != nil {
+ log.Printf("Couldn't stop DNS server: %s", err)
+ }
+}
+
func getInput() (string, error) {
scanner := bufio.NewScanner(os.Stdin)
scanner.Scan()
diff --git a/coredns.go b/coredns.go
index f6940abe..119b2371 100644
--- a/coredns.go
+++ b/coredns.go
@@ -74,3 +74,16 @@ func reconfigureDNSServer() error {
return nil
}
+
+func stopDNSServer() error {
+ if !isRunning() {
+ return fmt.Errorf("Refusing to stop forwarding DNS server: not running")
+ }
+
+ err := dnsServer.Stop()
+ if err != nil {
+ return errorx.Decorate(err, "Couldn't stop forwarding DNS server")
+ }
+
+ return nil
+}