refactor(main): move main logic to separate package

The use case is to make it easy to embed etcd into another programs.
Currently, the only way of doing this to copy and paste the contents
of the `main()` in etcd.go.
With this commit, contents of the `main()` is moved into `Etcd.Run()`.

etcd.go

@@ -18,26 +18,14 @@ package main
 
 import (
 	"fmt"
-	"net/http"
 	"os"
-	"path/filepath"
-	"runtime"
-	"time"
-
-	goetcd "github.com/coreos/etcd/third_party/github.com/coreos/go-etcd/etcd"
-	golog "github.com/coreos/etcd/third_party/github.com/coreos/go-log/log"
-	"github.com/coreos/etcd/third_party/github.com/goraft/raft"
 
 	"github.com/coreos/etcd/config"
-	ehttp "github.com/coreos/etcd/http"
-	"github.com/coreos/etcd/log"
-	"github.com/coreos/etcd/metrics"
+	"github.com/coreos/etcd/etcd"
 	"github.com/coreos/etcd/server"
-	"github.com/coreos/etcd/store"
 )
 
 func main() {
-	// Load configuration.
 	var config = config.New()
 	if err := config.Load(os.Args[1:]); err != nil {
 		fmt.Println(server.Usage() + "\n")
@@ -51,138 +39,6 @@ func main() {
 		os.Exit(0)
 	}
 
-	// Enable options.
-	if config.VeryVeryVerbose {
-		log.Verbose = true
-		raft.SetLogLevel(raft.Trace)
-		goetcd.SetLogger(
-			golog.New(
-				"go-etcd",
-				false,
-				golog.CombinedSink(
-					os.Stdout,
-					"[%s] %s %-9s | %s\n",
-					[]string{"prefix", "time", "priority", "message"},
-				),
-			),
-		)
-	} else if config.VeryVerbose {
-		log.Verbose = true
-		raft.SetLogLevel(raft.Debug)
-	} else if config.Verbose {
-		log.Verbose = true
-	}
-	if config.CPUProfileFile != "" {
-		profile(config.CPUProfileFile)
-	}
-
-	if config.DataDir == "" {
-		log.Fatal("The data dir was not set and could not be guessed from machine name")
-	}
-
-	// 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)
-	}
-
-	// Warn people if they have an info file
-	info := filepath.Join(config.DataDir, "info")
-	if _, err := os.Stat(info); err == nil {
-		log.Warnf("All cached configuration is now ignored. The file %s can be removed.", info)
-	}
-
-	var mbName string
-	if config.Trace() {
-		mbName = config.MetricsBucketName()
-		runtime.SetBlockProfileRate(1)
-	}
-
-	mb := metrics.NewBucket(mbName)
-
-	if config.GraphiteHost != "" {
-		err := mb.Publish(config.GraphiteHost)
-		if err != nil {
-			panic(err)
-		}
-	}
-
-	// Retrieve CORS configuration
-	corsInfo, err := ehttp.NewCORSInfo(config.CorsOrigins)
-	if err != nil {
-		log.Fatal("CORS:", err)
-	}
-
-	// Create etcd key-value store and registry.
-	store := store.New()
-	registry := server.NewRegistry(store)
-
-	// Create stats objects
-	followersStats := server.NewRaftFollowersStats(config.Name)
-	serverStats := server.NewRaftServerStats(config.Name)
-
-	// Calculate all of our timeouts
-	heartbeatInterval := time.Duration(config.Peer.HeartbeatInterval) * time.Millisecond
-	electionTimeout := time.Duration(config.Peer.ElectionTimeout) * time.Millisecond
-	dialTimeout := (3 * heartbeatInterval) + electionTimeout
-	responseHeaderTimeout := (3 * heartbeatInterval) + electionTimeout
-
-	// Create peer server
-	psConfig := server.PeerServerConfig{
-		Name:          config.Name,
-		Scheme:        config.PeerTLSInfo().Scheme(),
-		URL:           config.Peer.Addr,
-		SnapshotCount: config.SnapshotCount,
-		RetryTimes:    config.MaxRetryAttempts,
-		RetryInterval: config.RetryInterval,
-	}
-	ps := server.NewPeerServer(psConfig, registry, store, &mb, followersStats, serverStats)
-
-	// Create raft transporter and server
-	raftTransporter := server.NewTransporter(followersStats, serverStats, registry, heartbeatInterval, dialTimeout, responseHeaderTimeout)
-	if psConfig.Scheme == "https" {
-		raftClientTLSConfig, err := config.PeerTLSInfo().ClientConfig()
-		if err != nil {
-			log.Fatal("raft client TLS error: ", err)
-		}
-		raftTransporter.SetTLSConfig(*raftClientTLSConfig)
-	}
-	raftServer, err := raft.NewServer(config.Name, config.DataDir, raftTransporter, store, ps, "")
-	if err != nil {
-		log.Fatal(err)
-	}
-	raftServer.SetElectionTimeout(electionTimeout)
-	raftServer.SetHeartbeatInterval(heartbeatInterval)
-	ps.SetRaftServer(raftServer)
-
-	// Create etcd server
-	s := server.New(config.Name, config.Addr, ps, registry, store, &mb)
-
-	if config.Trace() {
-		s.EnableTracing()
-	}
-
-	ps.SetServer(s)
-
-	// Generating config could be slow.
-	// Put it here to make listen happen immediately after peer-server starting.
-	peerTLSConfig := server.TLSServerConfig(config.PeerTLSInfo())
-	etcdTLSConfig := server.TLSServerConfig(config.EtcdTLSInfo())
-
-	go func() {
-		// Starting peer server should be followed close by listening on its port
-		// If not, it may leave many requests unaccepted, or cannot receive heartbeat from the cluster.
-		// One severe problem caused if failing receiving heartbeats is when the second node joins one-node cluster,
-		// the cluster could be out of work as long as the two nodes cannot transfer messages.
-		ps.Start(config.Snapshot, config.Discovery, config.Peers)
-		log.Infof("peer server [name %s, listen on %s, advertised url %s]", ps.Config.Name, config.Peer.BindAddr, ps.Config.URL)
-		l := server.NewListener(psConfig.Scheme, config.Peer.BindAddr, peerTLSConfig)
-
-		sHTTP := &ehttp.CORSHandler{ps.HTTPHandler(), corsInfo}
-		log.Fatal(http.Serve(l, sHTTP))
-	}()
-
-	log.Infof("etcd server [name %s, listen on %s, advertised url %s]", s.Name, config.BindAddr, s.URL())
-	l := server.NewListener(config.EtcdTLSInfo().Scheme(), config.BindAddr, etcdTLSConfig)
-	sHTTP := &ehttp.CORSHandler{s.HTTPHandler(), corsInfo}
-	log.Fatal(http.Serve(l, sHTTP))
+	var etcd = etcd.New(config)
+	etcd.Run()
 }

etcd/etcd.go

@@ -0,0 +1,192 @@
+/*
+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 etcd
+
+import (
+	"net/http"
+	"os"
+	"path/filepath"
+	"runtime"
+	"time"
+
+	goetcd "github.com/coreos/etcd/third_party/github.com/coreos/go-etcd/etcd"
+	golog "github.com/coreos/etcd/third_party/github.com/coreos/go-log/log"
+	"github.com/coreos/etcd/third_party/github.com/goraft/raft"
+
+	"github.com/coreos/etcd/config"
+	ehttp "github.com/coreos/etcd/http"
+	"github.com/coreos/etcd/log"
+	"github.com/coreos/etcd/metrics"
+	"github.com/coreos/etcd/server"
+	"github.com/coreos/etcd/store"
+)
+
+type Etcd struct {
+	Config     *config.Config     // etcd config
+	Store      store.Store        // data store
+	Registry   *server.Registry   // stores URL information for nodes
+	Server     *server.Server     // http server, runs on 4001 by default
+	PeerServer *server.PeerServer // peer server, runs on 7001 by default
+}
+
+// New returns a new Etcd instance.
+func New(c *config.Config) *Etcd {
+	if c == nil {
+		c = config.New()
+	}
+	return &Etcd{
+		Config: c,
+	}
+}
+
+// Run etcd.
+func (e *Etcd) Run() {
+	// Enable options.
+	if e.Config.VeryVeryVerbose {
+		log.Verbose = true
+		raft.SetLogLevel(raft.Trace)
+		goetcd.SetLogger(
+			golog.New(
+				"go-etcd",
+				false,
+				golog.CombinedSink(
+					os.Stdout,
+					"[%s] %s %-9s | %s\n",
+					[]string{"prefix", "time", "priority", "message"},
+				),
+			),
+		)
+	} else if e.Config.VeryVerbose {
+		log.Verbose = true
+		raft.SetLogLevel(raft.Debug)
+	} else if e.Config.Verbose {
+		log.Verbose = true
+	}
+	if e.Config.CPUProfileFile != "" {
+		profile(e.Config.CPUProfileFile)
+	}
+
+	if e.Config.DataDir == "" {
+		log.Fatal("The data dir was not set and could not be guessed from machine name")
+	}
+
+	// Create data directory if it doesn't already exist.
+	if err := os.MkdirAll(e.Config.DataDir, 0744); err != nil {
+		log.Fatalf("Unable to create path: %s", err)
+	}
+
+	// Warn people if they have an info file
+	info := filepath.Join(e.Config.DataDir, "info")
+	if _, err := os.Stat(info); err == nil {
+		log.Warnf("All cached configuration is now ignored. The file %s can be removed.", info)
+	}
+
+	var mbName string
+	if e.Config.Trace() {
+		mbName = e.Config.MetricsBucketName()
+		runtime.SetBlockProfileRate(1)
+	}
+
+	mb := metrics.NewBucket(mbName)
+
+	if e.Config.GraphiteHost != "" {
+		err := mb.Publish(e.Config.GraphiteHost)
+		if err != nil {
+			panic(err)
+		}
+	}
+
+	// Retrieve CORS configuration
+	corsInfo, err := ehttp.NewCORSInfo(e.Config.CorsOrigins)
+	if err != nil {
+		log.Fatal("CORS:", err)
+	}
+
+	// Create etcd key-value store and registry.
+	e.Store = store.New()
+	e.Registry = server.NewRegistry(e.Store)
+
+	// Create stats objects
+	followersStats := server.NewRaftFollowersStats(e.Config.Name)
+	serverStats := server.NewRaftServerStats(e.Config.Name)
+
+	// Calculate all of our timeouts
+	heartbeatInterval := time.Duration(e.Config.Peer.HeartbeatInterval) * time.Millisecond
+	electionTimeout := time.Duration(e.Config.Peer.ElectionTimeout) * time.Millisecond
+	dialTimeout := (3 * heartbeatInterval) + electionTimeout
+	responseHeaderTimeout := (3 * heartbeatInterval) + electionTimeout
+
+	// Create peer server
+	psConfig := server.PeerServerConfig{
+		Name:          e.Config.Name,
+		Scheme:        e.Config.PeerTLSInfo().Scheme(),
+		URL:           e.Config.Peer.Addr,
+		SnapshotCount: e.Config.SnapshotCount,
+		RetryTimes:    e.Config.MaxRetryAttempts,
+		RetryInterval: e.Config.RetryInterval,
+	}
+	e.PeerServer = server.NewPeerServer(psConfig, e.Registry, e.Store, &mb, followersStats, serverStats)
+
+	// Create raft transporter and server
+	raftTransporter := server.NewTransporter(followersStats, serverStats, e.Registry, heartbeatInterval, dialTimeout, responseHeaderTimeout)
+	if psConfig.Scheme == "https" {
+		raftClientTLSConfig, err := e.Config.PeerTLSInfo().ClientConfig()
+		if err != nil {
+			log.Fatal("raft client TLS error: ", err)
+		}
+		raftTransporter.SetTLSConfig(*raftClientTLSConfig)
+	}
+	raftServer, err := raft.NewServer(e.Config.Name, e.Config.DataDir, raftTransporter, e.Store, e.PeerServer, "")
+	if err != nil {
+		log.Fatal(err)
+	}
+	raftServer.SetElectionTimeout(electionTimeout)
+	raftServer.SetHeartbeatInterval(heartbeatInterval)
+	e.PeerServer.SetRaftServer(raftServer)
+
+	// Create etcd server
+	e.Server = server.New(e.Config.Name, e.Config.Addr, e.PeerServer, e.Registry, e.Store, &mb)
+
+	if e.Config.Trace() {
+		e.Server.EnableTracing()
+	}
+
+	e.PeerServer.SetServer(e.Server)
+
+	// Generating config could be slow.
+	// Put it here to make listen happen immediately after peer-server starting.
+	peerTLSConfig := server.TLSServerConfig(e.Config.PeerTLSInfo())
+	etcdTLSConfig := server.TLSServerConfig(e.Config.EtcdTLSInfo())
+
+	go func() {
+		// Starting peer server should be followed close by listening on its port
+		// If not, it may leave many requests unaccepted, or cannot receive heartbeat from the cluster.
+		// One severe problem caused if failing receiving heartbeats is when the second node joins one-node cluster,
+		// the cluster could be out of work as long as the two nodes cannot transfer messages.
+		e.PeerServer.Start(e.Config.Snapshot, e.Config.Discovery, e.Config.Peers)
+		log.Infof("peer server [name %s, listen on %s, advertised url %s]", e.PeerServer.Config.Name, e.Config.Peer.BindAddr, e.PeerServer.Config.URL)
+		l := server.NewListener(psConfig.Scheme, e.Config.Peer.BindAddr, e.Config.PeerTLSInfo())
+
+		sHTTP := &ehttp.CORSHandler{e.PeerServer.HTTPHandler(), corsInfo}
+		log.Fatal(http.Serve(l, sHTTP))
+	}()
+
+	log.Infof("etcd server [name %s, listen on %s, advertised url %s]", e.Server.Name, e.Config.BindAddr, e.Server.URL())
+	l := server.NewListener(e.Config.EtcdTLSInfo().Scheme(), e.Config.BindAddr, e.Config.EtcdTLSInfo())
+	sHTTP := &ehttp.CORSHandler{e.Server.HTTPHandler(), corsInfo}
+	log.Fatal(http.Serve(l, sHTTP))
+}

profile.go → etcd/profile.go

@@ -1,4 +1,4 @@
-package main
+package etcd
 
 import (
 	"os"