server/core/core.go

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 core

import (
	"flag"
	// import the grace package and parse grace cmd line
	_ "github.com/apache/servicecomb-service-center/pkg/grace"
	"github.com/apache/servicecomb-service-center/pkg/log"
	"github.com/apache/servicecomb-service-center/version"
	"os"
	"os/signal"
	"syscall"
	"time"
)

func Initialize() {
	// parse the cmd line
	ParseCommandLine()

	// initialize configuration
	Configure()

	go handleSignals()
}

func ParseCommandLine() {
	var printVer bool
	flag.BoolVar(&printVer, "v", false, "Print the version and exit.")
	flag.Parse()

	if printVer {
		version.Ver().Print()
		os.Exit(0)
	}
}

func handleSignals() {
	defer log.Sync()

	sigCh := make(chan os.Signal, 1)
	signal.Notify(sigCh,
		syscall.SIGINT,
		syscall.SIGTERM,
	)
	wait := 5 * time.Second
	for sig := range sigCh {
		switch sig {
		case syscall.SIGINT, syscall.SIGKILL, syscall.SIGTERM:
			<-time.After(wait)
			log.Warnf("waiting for server response timed out(%s), force shutdown", wait)
			os.Exit(1)
		default:
			log.Warnf("received signal '%v'", sig)
		}
	}
}