From 6c04ccb76d023a1cff867ccaf678fbc57efebd81 Mon Sep 17 00:00:00 2001
From: Julien Vehent <julien@linuxwall.info>
Date: Mon, 21 Apr 2014 09:09:51 -0400
Subject: [PATCH] Add System-V support

---
 service_linux.go | 154 +++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 150 insertions(+), 4 deletions(-)

diff --git a/service_linux.go b/service_linux.go
index ab98131..467f10b 100644
--- a/service_linux.go
+++ b/service_linux.go
@@ -1,6 +1,7 @@
 package service
 
 import (
+	"bufio"
 	"fmt"
 	"log/syslog"
 	"os"
@@ -12,13 +13,17 @@ import (
 )
 
 const (
-	initUpstart = initFlavor(iota)
+	initSystemV = initFlavor(iota)
+	initUpstart
 	initSystemd
 )
 
 func newService(name, displayName, description string) (Service, error) {
-	flavor := initUpstart
-	if _, err := os.Stat("/run/systemd/system"); err == nil {
+	flavor := initSystemV
+	if isUpstart() {
+		flavor = initUpstart
+	}
+	if isSystemd() {
 		flavor = initSystemd
 	}
 	s := &linuxService{
@@ -37,6 +42,32 @@ func newService(name, displayName, description string) (Service, error) {
 	return s, nil
 }
 
+func isUpstart() bool {
+	f, err := os.Open("/etc/lsb-release")
+	if err != nil {
+		return false
+	}
+	defer f.Close()
+	r := bufio.NewReader(f)
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		if scanner.Text() == "DISTRIB_ID=Ubuntu" {
+			return true
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		return false
+	}
+	return false
+}
+
+func isSystemd() bool {
+	if _, err := os.Stat("/run/systemd/system"); err == nil {
+		return true
+	}
+	return false
+}
+
 type linuxService struct {
 	flavor                         initFlavor
 	name, displayName, description string
@@ -47,6 +78,8 @@ type initFlavor uint8
 
 func (f initFlavor) String() string {
 	switch f {
+	case initSystemV:
+		return "System-V"
 	case initUpstart:
 		return "Upstart"
 	case initSystemd:
@@ -58,6 +91,8 @@ func (f initFlavor) String() string {
 
 func (f initFlavor) ConfigPath(name string) string {
 	switch f {
+	case initSystemV:
+		return "/etc/init.d/" + name
 	case initUpstart:
 		return "/etc/init/" + name + ".conf"
 	case initSystemd:
@@ -70,6 +105,8 @@ func (f initFlavor) ConfigPath(name string) string {
 func (f initFlavor) GetTemplate() *template.Template {
 	var templ string
 	switch f {
+	case initSystemV:
+		templ = systemVScript
 	case initUpstart:
 		templ = upstartScript
 	case initSystemd:
@@ -107,11 +144,26 @@ func (s *linuxService) Install() error {
 	}
 
 	err = s.flavor.GetTemplate().Execute(f, to)
-
 	if err != nil {
 		return err
 	}
 
+	if s.flavor == initSystemV {
+		if err = os.Chmod(confPath, 0755); err != nil {
+			return err
+		}
+		for _, i := range [...]string{"2", "3", "4", "5"} {
+			if err = os.Symlink(confPath, "/etc/rc"+i+".d/S50"+s.name); err != nil {
+				continue
+			}
+		}
+		for _, i := range [...]string{"0", "1", "6"} {
+			if err = os.Symlink(confPath, "/etc/rc"+i+".d/K02"+s.name); err != nil {
+				continue
+			}
+		}
+	}
+
 	if s.flavor == initSystemd {
 		return exec.Command("systemctl", "daemon-reload").Run()
 	}
@@ -165,6 +217,100 @@ func (s *linuxService) Info(format string, a ...interface{}) error {
 	return s.logger.Info(fmt.Sprintf(format, a...))
 }
 
+const systemVScript = `#!/bin/sh
+# For RedHat and cousins:
+# chkconfig: - 99 01
+# description: {{.Description}}
+# processname: {{.Path}}
+
+### BEGIN INIT INFO
+# Provides:          {{.Path}}
+# Required-Start:
+# Required-Stop:
+# Default-Start:     2 3 4 5
+# Default-Stop:      0 1 6
+# Short-Description: {{.Display}}
+# Description:       {{.Description}}
+### END INIT INFO
+
+cmd="{{.Path}}"
+
+name=$(basename $0)
+pid_file="/var/run/$name.pid"
+stdout_log="/var/log/$name.log"
+stderr_log="/var/log/$name.err"
+
+get_pid() {
+    cat "$pid_file"
+}
+
+is_running() {
+    [ -f "$pid_file" ] && ps $(get_pid) > /dev/null 2>&1
+}
+
+case "$1" in
+    start)
+        if is_running; then
+            echo "Already started"
+        else
+            echo "Starting $name"
+            $cmd >> "$stdout_log" 2>> "$stderr_log" &
+            echo $! > "$pid_file"
+            if ! is_running; then
+                echo "Unable to start, see $stdout_log and $stderr_log"
+                exit 1
+            fi
+        fi
+    ;;
+    stop)
+        if is_running; then
+            echo -n "Stopping $name.."
+            kill $(get_pid)
+            for i in {1..10}
+            do
+                if ! is_running; then
+                    break
+                fi
+                echo -n "."
+                sleep 1
+            done
+            echo
+            if is_running; then
+                echo "Not stopped; may still be shutting down or shutdown may have failed"
+                exit 1
+            else
+                echo "Stopped"
+                if [ -f "$pid_file" ]; then
+                    rm "$pid_file"
+                fi
+            fi
+        else
+            echo "Not running"
+        fi
+    ;;
+    restart)
+        $0 stop
+        if is_running; then
+            echo "Unable to stop, will not attempt to start"
+            exit 1
+        fi
+        $0 start
+    ;;
+    status)
+        if is_running; then
+            echo "Running"
+        else
+            echo "Stopped"
+            exit 1
+        fi
+    ;;
+    *)
+    echo "Usage: $0 {start|stop|restart|status}"
+    exit 1
+    ;;
+esac
+exit 0`
+
 const upstartScript = `# {{.Description}}
 
 description     "{{.Display}}"