Add daemon support

experimental/daemon/daemon.go

@@ -0,0 +1,165 @@
+package daemon
+
+import (
+	"io"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+
+	E "github.com/sagernet/sing/common/exceptions"
+	"github.com/sagernet/sing/common/rw"
+
+	"github.com/kardianos/service"
+	C "github.com/sagernet/sing-box/constant"
+)
+
+const (
+	DefaultDaemonName = "sing-box-daemon"
+	DefaultDaemonPort = 9091
+)
+
+var defaultDaemonOptions = Options{
+	Listen:           "127.0.0.1",
+	ListenPort:       DefaultDaemonPort,
+	WorkingDirectory: workingDirectory(),
+}
+
+func workingDirectory() string {
+	switch runtime.GOOS {
+	case "linux":
+		return filepath.Join("/usr/local/lib", DefaultDaemonName)
+	default:
+		configDir, err := os.UserConfigDir()
+		if err == nil {
+			return filepath.Join(configDir, DefaultDaemonName)
+		} else {
+			return DefaultDaemonName
+		}
+	}
+}
+
+const systemdScript = `[Unit]
+Description=sing-box service
+Documentation=https://sing-box.sagernet.org
+After=network.target nss-lookup.target
+
+[Service]
+User=root
+ExecStart={{.Path|cmdEscape}}{{range .Arguments}} {{.|cmd}}{{end}}
+WorkingDirectory={{.WorkingDirectory|cmdEscape}}
+Restart=on-failure
+RestartSec=10s
+LimitNOFILE=infinity
+
+[Install]
+WantedBy=multi-user.target`
+
+type Daemon struct {
+	service          service.Service
+	workingDirectory string
+	executable       string
+}
+
+func New() (*Daemon, error) {
+	daemonInterface := NewInterface(defaultDaemonOptions)
+	executable := filepath.Join(defaultDaemonOptions.WorkingDirectory, "sing-box")
+	if C.IsWindows {
+		executable += ".exe"
+	}
+	daemonService, err := service.New(daemonInterface, &service.Config{
+		Name:        DefaultDaemonName,
+		Description: "The universal proxy platform.",
+		Arguments:   []string{"daemon", "run"},
+		Executable:  executable,
+		Option: service.KeyValue{
+			"SystemdScript": systemdScript,
+		},
+	})
+	if err != nil {
+		return nil, E.New(strings.ToLower(err.Error()))
+	}
+	return &Daemon{
+		service:          daemonService,
+		workingDirectory: defaultDaemonOptions.WorkingDirectory,
+		executable:       executable,
+	}, nil
+}
+
+func (d *Daemon) Install() error {
+	_, err := d.service.Status()
+	if err != service.ErrNotInstalled {
+		d.service.Stop()
+		err = d.service.Uninstall()
+		if err != nil {
+			return err
+		}
+	}
+	executablePath, err := os.Executable()
+	if err != nil {
+		return err
+	}
+	if !rw.FileExists(d.workingDirectory) {
+		err = os.MkdirAll(d.workingDirectory, 0o755)
+		if err != nil {
+			return err
+		}
+	}
+	outputFile, err := os.OpenFile(d.executable, os.O_CREATE|os.O_WRONLY, 0o755)
+	if err != nil {
+		return err
+	}
+	inputFile, err := os.Open(executablePath)
+	if err != nil {
+		outputFile.Close()
+		return err
+	}
+	_, err = io.Copy(outputFile, inputFile)
+	inputFile.Close()
+	outputFile.Close()
+	if err != nil {
+		return err
+	}
+	err = d.service.Install()
+	if err != nil {
+		return err
+	}
+	return d.service.Start()
+}
+
+func (d *Daemon) Uninstall() error {
+	_, err := d.service.Status()
+	if err != service.ErrNotInstalled {
+		d.service.Stop()
+		err = d.service.Uninstall()
+		if err != nil {
+			return err
+		}
+	}
+	return os.RemoveAll(d.workingDirectory)
+}
+
+func (d *Daemon) Run() error {
+	d.chdir()
+	return d.service.Run()
+}
+
+func (d *Daemon) chdir() error {
+	executable, err := os.Executable()
+	if err != nil {
+		return err
+	}
+	return os.Chdir(filepath.Dir(executable))
+}
+
+func (d *Daemon) Start() error {
+	return d.service.Start()
+}
+
+func (d *Daemon) Stop() error {
+	return d.service.Stop()
+}
+
+func (d *Daemon) Restart() error {
+	return d.service.Restart()
+}