Storage node auto-updater skeleton (#2902)

cmd/auto-updater/main.go

@@ -0,0 +1,80 @@
+// Copyright (C) 2019 Storj Labs, Inc.
+// See LICENSE for copying information.
+
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"github.com/spf13/cobra"
+
+	"storj.io/storj/internal/sync2"
+)
+
+var (
+	rootCmd = &cobra.Command{
+		Use:   "auto-updater",
+		Short: "Auto-updater for storage node",
+	}
+	runCmd = &cobra.Command{
+		Use:   "run",
+		Short: "Run the auto updater for storage node",
+		RunE: func(cmd *cobra.Command, args []string) (err error) {
+			err = cmdRun(cmd, args)
+			if err != nil {
+				fmt.Println(err)
+				os.Exit(1)
+			}
+			return nil
+		},
+	}
+
+	interval       string
+	versionURL     string
+	binaryLocation string
+)
+
+func init() {
+	rootCmd.AddCommand(runCmd)
+
+	runCmd.Flags().StringVar(&interval, "interval", "06h", "interval for checking the new version")
+	runCmd.Flags().StringVar(&versionURL, "version-url", "https://version.storj.io/release/", "version server URL")
+	runCmd.Flags().StringVar(&binaryLocation, "binary-location", "storagenode.exe", "the storage node executable binary location")
+}
+
+func cmdRun(cmd *cobra.Command, args []string) (err error) {
+	ctx, cancel := context.WithCancel(context.Background())
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, syscall.SIGINT, syscall.SIGTERM)
+
+	go func() {
+		<-c
+
+		signal.Stop(c)
+		cancel()
+	}()
+
+	loopInterval, err := time.ParseDuration(interval)
+	if err != nil {
+		return fmt.Errorf("unable to parse interval parameter: %v", err)
+	}
+
+	loop := sync2.NewCycle(loopInterval)
+	err = loop.Run(ctx, func(ctx context.Context) (err error) {
+		fmt.Println("check new version")
+		return nil
+	})
+	if err != context.Canceled {
+		return err
+	}
+	return nil
+}
+
+func main() {
+	_ = rootCmd.Execute()
+}