Self update

Author: codehz

main.go

@@ -124,13 +124,48 @@ func (c *runCmd) Execute(_ context.Context, f *flag.FlagSet, _ ...interface{}) (
 	return subcommands.ExitSuccess
 }
 
+type updateCmd struct {
+	path string
+}
+
+func (*updateCmd) Name() string {
+	return "update"
+}
+
+func (*updateCmd) Synopsis() string {
+	return "Update Self"
+}
+
+func (*updateCmd) Usage() string {
+	return "update [-target]\n"
+}
+
+func (c *updateCmd) SetFlags(f *flag.FlagSet) {
+	f.StringVar(&c.path, "path", "./mcpeserver", "Download target")
+}
+
+func (c *updateCmd) Execute(_ context.Context, f *flag.FlagSet, _ ...interface{}) (ret subcommands.ExitStatus) {
+	defer func() {
+		if r := recover(); r != nil {
+			fmt.Println("\033[5;91mError: \n", r)
+			ret = subcommands.ExitFailure
+		}
+	}()
+	printInfo("Get Latest Release...")
+	url := getServerURL()
+	printPair("URL", url)
+	fetchBinary(url, c.path)
+	return subcommands.ExitSuccess
+}
+
 func main() {
 	subcommands.Register(subcommands.HelpCommand(), "")
 	subcommands.Register(subcommands.FlagsCommand(), "")
 	subcommands.Register(subcommands.CommandsCommand(), "")
 	subcommands.Register(&downloadCmd{}, "")
 	subcommands.Register(&unpackCmd{}, "")
 	subcommands.Register(&runCmd{}, "")
+	subcommands.Register(&updateCmd{}, "")
 
 	flag.Parse()
 	ctx := context.Background()

update.go

@@ -0,0 +1,60 @@
+package main
+
+import (
+	"encoding/json"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"time"
+
+	"gopkg.in/cheggaaa/pb.v1"
+)
+
+type releaseInfo struct {
+	Assets []struct {
+		URL string `json:"browser_download_url"`
+	} `json:"assets"`
+}
+
+func getServerURL() string {
+	resp, err := http.Get("https://api.github.com/repos/codehz/mcpeserver/releases/latest")
+	if err != nil {
+		panic(err)
+	}
+	defer resp.Body.Close()
+	contents, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		panic(err)
+	}
+	info := releaseInfo{}
+	if err = json.Unmarshal(contents, &info); err != nil {
+		panic(err)
+	}
+	return info.Assets[0].URL
+}
+
+func fetchBinary(url string, target string) {
+	out, err := os.OpenFile(target+".tmp", os.O_CREATE|os.O_RDWR, 0755)
+	if err != nil {
+		panic(err)
+	}
+	defer out.Close()
+	resp, err := http.Get(url)
+	if err != nil {
+		panic(err)
+	}
+	defer resp.Body.Close()
+
+	bar := pb.StartNew(int(resp.ContentLength))
+	bar.SetUnits(pb.U_BYTES_DEC)
+	bar.SetRefreshRate(time.Millisecond * 20)
+	bar.Prefix("mcpeserver")
+	bar.Start()
+	_, err = io.Copy(out, bar.NewProxyReader(resp.Body))
+	if err != nil {
+		panic(err)
+	}
+	bar.FinishPrint("\033[0;34mUpdate Finished.\033[0m")
+	os.Rename(target+".tmp", target)
+}