feat: daemon installer

Readme.md

@@ -1,6 +1,6 @@
 # Sandal
 
-Sandal is a basic, deamonless container system for Linux-embedded systems.
+Sandal is a basic, lightweight container system for Linux-embedded systems.
 
 This project aims to have a container system which light weight and respects systems disk usage.  
 It utilizes the squashfs filesystem as a container image, so you can execute the container directly from the file, and easy to distribute it with portable media.
@@ -162,6 +162,8 @@ sandal cmd minecraft
 
 Run all startup containers and watch in case of hang errors.
 
+To enable systemd or runit, you can use `sandal daemon -install`.
+
 ```bash
 sandal daemon
 2024/06/27 03:09:37 INFO daemon started

pkg/cmd/daemon.go

@@ -1,6 +1,8 @@
 package cmd
 
 import (
+	"errors"
+	"flag"
 	"fmt"
 	"log/slog"
 	"os"
@@ -13,6 +15,21 @@ import (
 
 func deamon(args []string) error {
 
+	var (
+		install bool
+		help    bool
+	)
+	flags := flag.NewFlagSet("deamon", flag.ExitOnError)
+
+	flags.BoolVar(&install, "install", false, "install service files under /etc/init.d/sandal and /etc/systemd/system/sandal.service")
+	flags.BoolVar(&help, "help", false, "show this help message")
+
+	flags.Parse(args)
+
+	if install {
+		return installServices()
+	}
+
 	updateContainers := make(chan bool, 1)
 
 	conts, _ := config.AllContainers()
@@ -35,6 +52,10 @@ func deamon(args []string) error {
 	}()
 
 	slog.Info("daemon started")
+	if _, err := os.Stat("/etc/init.d/sandal"); err != nil {
+		slog.Info(`You can enable sandal deamon at startup with "sandal daemon -install" command.` +
+			`It will install service files for systemd and runit`)
+	}
 	for {
 		for _, cont := range conts {
 			// oldContPid := cont.ContPid
@@ -100,3 +121,121 @@ func deamon(args []string) error {
 
 	// return nil
 }
+
+const initdSandal = `#!/bin/sh
+
+### BEGIN INIT INFO
+# Provides:		sandal
+# Required-Start:	$remote_fs $syslog
+# Required-Stop:	$remote_fs $syslog
+# Default-Start:	2 3 4 5
+# Default-Stop:
+# Short-Description:	Sandal daemon
+### END INIT INFO
+
+set -e
+
+# /etc/init.d/sandal: start and stop the Sandal daemon
+
+
+umask 022
+
+
+. /lib/lsb/init-functions
+
+export PATH="${PATH:+$PATH:}/usr/sbin:/sbin"
+
+SANDAL_OPTS="daemon"
+
+case "$1" in
+  start)
+	log_daemon_msg "Starting Sandal" "sandal" || true
+	# shellcheck disable=SC2086
+	if start-stop-daemon --start --quiet --background -m --oknodo --chuid 0:0 --pidfile /run/sandal.pid --exec /bin/sandal -- $SANDAL_OPTS; then
+	    log_end_msg 0 || true
+	else
+	    log_end_msg 1 || true
+	fi
+	;;
+  stop)
+	log_daemon_msg "Stopping Sandal" "sandal" || true
+	if start-stop-daemon --stop --quiet --oknodo --pidfile /run/sandal.pid --exec /bin/sandal; then
+	    log_end_msg 0 || true
+	else
+	    log_end_msg 1 || true
+	fi
+	;;
+
+  restart)
+	log_daemon_msg "Restarting Sandal" "sandal" || true
+	start-stop-daemon --stop --background -m --quiet --oknodo --retry 30 --pidfile /run/sandal.pid --exec /bin/sandal
+	# shellcheck disable=SC2086
+	if start-stop-daemon --start --quiet --oknodo --chuid 0:0 --pidfile /run/sandal.pid --exec /bin/sandal -- $SANDAL_OPTS; then
+	    log_end_msg 0 || true
+	else
+	    log_end_msg 1 || true
+	fi
+	;;
+
+  status)
+	status_of_proc -p /run/sandal.pid /bin/sandal sandal && exit 0 || exit $?
+	;;
+
+  *)
+	log_action_msg "Usage: /etc/init.d/sandal {start|stop|restart|status}" || true
+	exit 1
+esac
+
+exit 0`
+
+const systemdSandalService = `
+[Unit]
+Description=sandal daemon
+After=network.target local-fs.target remote-fs.target
+
+[Service]
+User=root
+RuntimeDirectory=sandal
+LogsDirectory=sandal
+StateDirectory=sandal
+ExecStart=/usr/bin/sandal daemon
+Restart=on-abort
+
+[Install]
+WantedBy=multi-user.target`
+
+func installServices() error {
+
+	var errs []error
+	slog.Info("creating /etc/init.d/sandal")
+	err := os.WriteFile("/etc/init.d/sandal", []byte(initdSandal), 0755)
+	if err == nil {
+		os.Chmod("/etc/init.d/sandal", 0755) // os.write does not set permission for existing file
+		slog.Info("enabling service /etc/init.d/sandal -> /etc/rc2.d/S01sandal")
+		err = os.Symlink("/etc/init.d/sandal", "/etc/rc2.d/S01sandal")
+		if err != nil {
+			errs = append(errs, err)
+		}
+	} else {
+		errs = append(errs, err)
+	}
+
+	slog.Info("creating /etc/systemd/system/sandal.service")
+	err = os.WriteFile("/etc/systemd/system/sandal.service", []byte(systemdSandalService), 0755)
+	if err == nil {
+		os.Chmod("/etc/systemd/system/sandal.service", 0755) // os.write does not set permission for existing file
+		slog.Info("enabling /etc/systemd/system/sandal.service")
+		cmd := exec.Command("systemctl", "enable", "sandal.service")
+		cmd.Stderr = os.Stderr
+		cmd.Stdout = os.Stdout
+		err = cmd.Start()
+		if err != nil {
+			errs = append(errs, err)
+		}
+	} else {
+		errs = append(errs, err)
+	}
+
+	return errors.Join(errs...)
+
+}