Use cobra (#234)

switch to cobra

Signed-off-by: yxxhero <aiopsclub@163.com>

main.go

@@ -5,13 +5,23 @@ import (
 	"os"
 
 	"github.com/helmfile/helmfile/cmd"
+	"github.com/helmfile/helmfile/pkg/config"
+	"github.com/urfave/cli"
 )
 
+func warning(format string, v ...interface{}) {
+	format = fmt.Sprintf("WARNING: %s\n", format)
+	fmt.Fprintf(os.Stderr, format, v...)
+}
+
 func main() {
-	rootCmd := cmd.RootCommand()
-	err := rootCmd.Run(os.Args)
+	globalConfig := new(config.GlobalOptions)
+	rootCmd, err := cmd.NewRootCmd(globalConfig, os.Args[1:])
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "%v\n", err)
-		os.Exit(3)
+		warning("%+v", err)
+		os.Exit(1)
+	}
+	if err := rootCmd.Execute(); err != nil {
+		cli.HandleExitCoder(err)
 	}
 }