academy-chauffeurs - updater/main.go

     1  package main // import "vimagination.zapto.org/academy-chauffeurs/updater"
     2  
     3  import (
     4  	"bufio"
     5  	"flag"
     6  	"fmt"
     7  	"io"
     8  	"net/http"
     9  	"os"
    10  	"path"
    11  	"time"
    12  
    13  	"github.com/cheggaaa/pb"
    14  	"golang.org/x/sys/windows/svc"
    15  	"golang.org/x/sys/windows/svc/mgr"
    16  )
    17  
    18  var (
    19  	executeablePath = flag.String("exe", "c:\\ac\\academy-chauffeurs.exe", "path to executeable")
    20  	serviceName     = flag.String("svc", "Academy Chauffeurs", "service name")
    21  	url             = flag.String("url", "http://vimagination.zapto.org/ac.exe", "update url")
    22  )
    23  
    24  func Err(err error) bool {
    25  	if err != nil {
    26  		fmt.Println(err)
    27  		r := bufio.NewReader(os.Stdin)
    28  		r.ReadString('\n')
    29  		return true
    30  	}
    31  	return false
    32  }
    33  
    34  func main() {
    35  	flag.Parse()
    36  	fname := path.Clean(*executeablePath)
    37  	/*_, err := os.Stat(fname)
    38  	if os.IsNotExist(err) {
    39  		Err(errors.New("executable not found"))
    40  		return
    41  	}*/
    42  	m, err := mgr.Connect()
    43  	if Err(err) {
    44  		return
    45  	}
    46  	defer m.Disconnect()
    47  	s, err := m.OpenService(*serviceName)
    48  	if Err(err) {
    49  		return
    50  	}
    51  	status, err := s.Query()
    52  	if Err(err) {
    53  		return
    54  	}
    55  	switch status.State {
    56  	case svc.StopPending:
    57  		fmt.Println("Waiting for service to stop")
    58  		time.Sleep(5 * time.Second)
    59  		fmt.Println("...done waiting")
    60  	case svc.Stopped:
    61  	default:
    62  		fmt.Println("Stopping service...")
    63  		_, err = s.Control(svc.Stop)
    64  		if Err(err) {
    65  			return
    66  		}
    67  		time.Sleep(5 * time.Second)
    68  		fmt.Println("...service stopped")
    69  	}
    70  	defer s.Start()
    71  	resp, err := http.Get(*url)
    72  	if Err(err) {
    73  		return
    74  	}
    75  	defer resp.Body.Close()
    76  	f, err := os.Create(fname + ".new")
    77  	if Err(err) {
    78  		return
    79  	}
    80  	fmt.Println("Downloading...")
    81  	bar := pb.New64(resp.ContentLength).SetUnits(pb.U_BYTES)
    82  	bar.Start()
    83  	w := io.MultiWriter(f, bar)
    84  	_, err = io.Copy(w, resp.Body)
    85  	f.Close()
    86  	if Err(err) {
    87  		os.Remove(fname + ".new")
    88  		return
    89  	}
    90  	bar.FinishPrint("...done")
    91  	Err(os.Remove(fname))
    92  	Err(os.Rename(fname+".new", fname))
    93  }