main.go

// Copyright (c) 2018 SAP SE or an SAP affiliate company. All rights reserved. This file is licensed under the Apache Software License, v. 2 except as noted otherwise in the LICENSE file.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package main

import (
	"fmt"
	"os"
	"os/signal"
	"runtime"

	"github.com/gardener/etcd-backup-restore/cmd"
)

var onlyOneSignalHandler = make(chan struct{})

func main() {
	if len(os.Getenv("GOMAXPROCS")) == 0 {
		runtime.GOMAXPROCS(runtime.NumCPU())
	}

	stopCh := setupSignalHandler()
	command := cmd.NewBackupRestoreCommand(stopCh)
	if err := command.Execute(); err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
}

// SetupSignalHandler registered for SIGTERM and SIGINT. A stop channel is returned
// which is closed on one of these signals. If a second signal is caught, the program
// is terminated with exit code 1.
func setupSignalHandler() <-chan struct{} {
	close(onlyOneSignalHandler) // panics when called twice

	var shutdownSignals = []os.Signal{os.Interrupt}
	stop := make(chan struct{})
	c := make(chan os.Signal, 2)
	signal.Notify(c, shutdownSignals...)
	go func() {
		<-c
		close(stop)
		<-c
		os.Exit(1) // second signal. Exit directly.
	}()

	return stop
}