etcd.go

/*
Copyright 2013 CoreOS Inc.

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 (
	"flag"
	"fmt"
	"io/ioutil"
	"os"
	"os/signal"
	"runtime/pprof"

	"github.com/coreos/etcd/log"
	"github.com/coreos/etcd/server"
	"github.com/coreos/etcd/store"
	"github.com/coreos/go-raft"
)

func main() {
	parseFlags()

	// Load configuration.
	var config = server.NewConfig()
	if err := config.Load(os.Args[1:]); err != nil {
		log.Fatal("Configuration error:", err)
	}

	// Turn on logging.
	if config.VeryVerbose {
		log.Verbose = true
		raft.SetLogLevel(raft.Debug)
	} else if config.Verbose {
		log.Verbose = true
	}

	// Load info object.
	info, err := config.Info()
	if err != nil {
		log.Fatal("info:", err)
	}
	if info.Name == "" {
		host, err := os.Hostname()
		if err != nil || host == "" {
			log.Fatal("Machine name required and hostname not set. e.g. '-n=machine_name'")
		}
		log.Warnf("Using hostname %s as the machine name. You must ensure this name is unique among etcd machines.", host)
		info.Name = host
	}

	// Setup a default directory based on the machine name
	if config.DataDir == "" {
		config.DataDir = info.Name + ".etcd"
		log.Warnf("Using the directory %s as the etcd configuration directory because a directory was not specified. ", config.DataDir)
	}

	// Create data directory if it doesn't already exist.
	if err := os.MkdirAll(config.DataDir, 0744); err != nil {
		log.Fatalf("Unable to create path: %s", err)
	}

	// Retrieve TLS configuration.
	tlsConfig, err := info.EtcdTLS.Config()
	if err != nil {
		log.Fatal("Client TLS:", err)
	}
	peerTLSConfig, err := info.RaftTLS.Config()
	if err != nil {
		log.Fatal("Peer TLS:", err)
	}

	// Create etcd key-value store and registry.
	store := store.New()
	registry := server.NewRegistry(store)

	// Create peer server.
	ps := server.NewPeerServer(info.Name, config.DataDir, info.RaftURL, info.RaftListenHost, &peerTLSConfig, &info.RaftTLS, registry, store, config.SnapCount)
	ps.MaxClusterSize = config.MaxClusterSize
	ps.RetryTimes = config.MaxRetryAttempts

	// Create client server.
	s := server.New(info.Name, info.EtcdURL, info.EtcdListenHost, &tlsConfig, &info.EtcdTLS, ps, registry, store)
	if err := s.AllowOrigins(config.Cors); err != nil {
		panic(err)
	}

	ps.SetServer(s)

	// Run peer server in separate thread while the client server blocks.
	go func() {
		log.Fatal(ps.ListenAndServe(config.Snapshot, config.Machines))
	}()
	log.Fatal(s.ListenAndServe())
}

// Parses non-configuration flags.
func parseFlags() {
	var versionFlag bool
	var cpuprofile string

	f := flag.NewFlagSet(os.Args[0], -1)
	f.SetOutput(ioutil.Discard)
	f.BoolVar(&versionFlag, "version", false, "print the version and exit")
	f.StringVar(&cpuprofile, "cpuprofile", "", "write cpu profile to file")
	f.Parse(os.Args[1:])

	// Print version if necessary.
	if versionFlag {
		fmt.Println(server.ReleaseVersion)
		os.Exit(0)
	}

	// Begin CPU profiling if specified.
	if cpuprofile != "" {
		f, err := os.Create(cpuprofile)
		if err != nil {
			log.Fatal(err)
		}
		pprof.StartCPUProfile(f)

		c := make(chan os.Signal, 1)
		signal.Notify(c, os.Interrupt)
		go func() {
			sig := <-c
			log.Infof("captured %v, stopping profiler and exiting..", sig)
			pprof.StopCPUProfile()
			os.Exit(1)
		}()
	}
}