From 209dd22ea0c6ea06aca47cb53f68ae2cf0d40831 Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Thu, 3 May 2018 14:50:57 +0200
Subject: Daemonize with environment variable

---
 daemon.go | 25 -------------------------
 main.go   | 25 +++++++++++++++++++------
 2 files changed, 19 insertions(+), 31 deletions(-)
 delete mode 100644 daemon.go

diff --git a/daemon.go b/daemon.go
deleted file mode 100644
index e2ded87..0000000
--- a/daemon.go
+++ /dev/null
@@ -1,25 +0,0 @@
-package main
-
-import (
-	"os"
-)
-
-func Daemonize(attr *os.ProcAttr) error {
-	path, err := os.Executable()
-	if err != nil {
-		return err
-	}
-
-	argv := []string{os.Args[0], "--foreground"}
-	argv = append(argv, os.Args[1:]...)
-	process, err := os.StartProcess(
-		path,
-		argv,
-		attr,
-	)
-	if err != nil {
-		return err
-	}
-	process.Release()
-	return nil
-}
diff --git a/main.go b/main.go
index 3358469..f0705c8 100644
--- a/main.go
+++ b/main.go
@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"os"
 	"os/signal"
-	"runtime"
 	"strconv"
 )
 
@@ -16,6 +15,7 @@ const (
 const (
 	ENV_WG_TUN_FD  = "WG_TUN_FD"
 	ENV_WG_UAPI_FD = "WG_UAPI_FD"
+	ENV_WG_PROCESS_FOREGROUND = "WG_PROCESS_FOREGROUND"
 )
 
 func printUsage() {
@@ -55,6 +55,10 @@ func main() {
 		interfaceName = os.Args[1]
 	}
 
+	if !foreground {
+		foreground = os.Getenv(ENV_WG_PROCESS_FOREGROUND) == "1"
+	}
+
 	// get log level (default: info)
 
 	logLevel := func() int {
@@ -129,6 +133,7 @@ func main() {
 		env := os.Environ()
 		env = append(env, fmt.Sprintf("%s=3", ENV_WG_TUN_FD))
 		env = append(env, fmt.Sprintf("%s=4", ENV_WG_UAPI_FD))
+		env = append(env, fmt.Sprintf("%s=1", ENV_WG_PROCESS_FOREGROUND))
 		attr := &os.ProcAttr{
 			Files: []*os.File{
 				nil, // stdin
@@ -140,18 +145,26 @@ func main() {
 			Dir: ".",
 			Env: env,
 		}
-		err = Daemonize(attr)
+
+		path, err := os.Executable()
+		if err != nil {
+			logger.Error.Println("Failed to determine executable:", err)
+			os.Exit(ExitSetupFailed)
+		}
+
+		process, err := os.StartProcess(
+			path,
+			os.Args,
+			attr,
+		)
 		if err != nil {
 			logger.Error.Println("Failed to daemonize:", err)
 			os.Exit(ExitSetupFailed)
 		}
+		process.Release()
 		return
 	}
 
-	// increase number of go workers (for Go <1.5)
-
-	runtime.GOMAXPROCS(runtime.NumCPU())
-
 	// create wireguard device
 
 	device := NewDevice(tun, logger)
-- 
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