https://github.com/coreos/etcd
Tip revision: fca8add78a9d926166eb739b8e4a124434025ba3 authored by Gyuho Lee on 24 July 2018, 16:48:32 UTC
version: 3.3.9
version: 3.3.9
Tip revision: fca8add
etcd.go
// Copyright 2016 The etcd Authors
//
// 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 embed
import (
"context"
"crypto/tls"
"fmt"
"io/ioutil"
defaultLog "log"
"net"
"net/http"
"net/url"
"strconv"
"sync"
"time"
"github.com/coreos/etcd/compactor"
"github.com/coreos/etcd/etcdserver"
"github.com/coreos/etcd/etcdserver/api/etcdhttp"
"github.com/coreos/etcd/etcdserver/api/v2http"
"github.com/coreos/etcd/etcdserver/api/v2v3"
"github.com/coreos/etcd/etcdserver/api/v3client"
"github.com/coreos/etcd/etcdserver/api/v3rpc"
"github.com/coreos/etcd/pkg/cors"
"github.com/coreos/etcd/pkg/debugutil"
runtimeutil "github.com/coreos/etcd/pkg/runtime"
"github.com/coreos/etcd/pkg/transport"
"github.com/coreos/etcd/pkg/types"
"github.com/coreos/etcd/rafthttp"
"github.com/coreos/pkg/capnslog"
grpc_prometheus "github.com/grpc-ecosystem/go-grpc-prometheus"
"github.com/soheilhy/cmux"
"google.golang.org/grpc"
"google.golang.org/grpc/keepalive"
)
var plog = capnslog.NewPackageLogger("github.com/coreos/etcd", "embed")
const (
// internal fd usage includes disk usage and transport usage.
// To read/write snapshot, snap pkg needs 1. In normal case, wal pkg needs
// at most 2 to read/lock/write WALs. One case that it needs to 2 is to
// read all logs after some snapshot index, which locates at the end of
// the second last and the head of the last. For purging, it needs to read
// directory, so it needs 1. For fd monitor, it needs 1.
// For transport, rafthttp builds two long-polling connections and at most
// four temporary connections with each member. There are at most 9 members
// in a cluster, so it should reserve 96.
// For the safety, we set the total reserved number to 150.
reservedInternalFDNum = 150
)
// Etcd contains a running etcd server and its listeners.
type Etcd struct {
Peers []*peerListener
Clients []net.Listener
// a map of contexts for the servers that serves client requests.
sctxs map[string]*serveCtx
metricsListeners []net.Listener
Server *etcdserver.EtcdServer
cfg Config
stopc chan struct{}
errc chan error
closeOnce sync.Once
}
type peerListener struct {
net.Listener
serve func() error
close func(context.Context) error
}
// StartEtcd launches the etcd server and HTTP handlers for client/server communication.
// The returned Etcd.Server is not guaranteed to have joined the cluster. Wait
// on the Etcd.Server.ReadyNotify() channel to know when it completes and is ready for use.
func StartEtcd(inCfg *Config) (e *Etcd, err error) {
if err = inCfg.Validate(); err != nil {
return nil, err
}
serving := false
e = &Etcd{cfg: *inCfg, stopc: make(chan struct{})}
cfg := &e.cfg
defer func() {
if e == nil || err == nil {
return
}
if !serving {
// errored before starting gRPC server for serveCtx.serversC
for _, sctx := range e.sctxs {
close(sctx.serversC)
}
}
e.Close()
e = nil
}()
if e.Peers, err = startPeerListeners(cfg); err != nil {
return e, err
}
if e.sctxs, err = startClientListeners(cfg); err != nil {
return e, err
}
for _, sctx := range e.sctxs {
e.Clients = append(e.Clients, sctx.l)
}
var (
urlsmap types.URLsMap
token string
)
memberInitialized := true
if !isMemberInitialized(cfg) {
memberInitialized = false
urlsmap, token, err = cfg.PeerURLsMapAndToken("etcd")
if err != nil {
return e, fmt.Errorf("error setting up initial cluster: %v", err)
}
}
// AutoCompactionRetention defaults to "0" if not set.
if len(cfg.AutoCompactionRetention) == 0 {
cfg.AutoCompactionRetention = "0"
}
autoCompactionRetention, err := parseCompactionRetention(cfg.AutoCompactionMode, cfg.AutoCompactionRetention)
if err != nil {
return e, err
}
srvcfg := etcdserver.ServerConfig{
Name: cfg.Name,
ClientURLs: cfg.ACUrls,
PeerURLs: cfg.APUrls,
DataDir: cfg.Dir,
DedicatedWALDir: cfg.WalDir,
SnapCount: cfg.SnapCount,
MaxSnapFiles: cfg.MaxSnapFiles,
MaxWALFiles: cfg.MaxWalFiles,
InitialPeerURLsMap: urlsmap,
InitialClusterToken: token,
DiscoveryURL: cfg.Durl,
DiscoveryProxy: cfg.Dproxy,
NewCluster: cfg.IsNewCluster(),
ForceNewCluster: cfg.ForceNewCluster,
PeerTLSInfo: cfg.PeerTLSInfo,
TickMs: cfg.TickMs,
ElectionTicks: cfg.ElectionTicks(),
InitialElectionTickAdvance: cfg.InitialElectionTickAdvance,
AutoCompactionRetention: autoCompactionRetention,
AutoCompactionMode: cfg.AutoCompactionMode,
QuotaBackendBytes: cfg.QuotaBackendBytes,
MaxTxnOps: cfg.MaxTxnOps,
MaxRequestBytes: cfg.MaxRequestBytes,
StrictReconfigCheck: cfg.StrictReconfigCheck,
ClientCertAuthEnabled: cfg.ClientTLSInfo.ClientCertAuth,
AuthToken: cfg.AuthToken,
InitialCorruptCheck: cfg.ExperimentalInitialCorruptCheck,
CorruptCheckTime: cfg.ExperimentalCorruptCheckTime,
Debug: cfg.Debug,
}
if e.Server, err = etcdserver.NewServer(srvcfg); err != nil {
return e, err
}
// buffer channel so goroutines on closed connections won't wait forever
e.errc = make(chan error, len(e.Peers)+len(e.Clients)+2*len(e.sctxs))
// newly started member ("memberInitialized==false")
// does not need corruption check
if memberInitialized {
if err = e.Server.CheckInitialHashKV(); err != nil {
// set "EtcdServer" to nil, so that it does not block on "EtcdServer.Close()"
// (nothing to close since rafthttp transports have not been started)
e.Server = nil
return e, err
}
}
e.Server.Start()
if err = e.servePeers(); err != nil {
return e, err
}
if err = e.serveClients(); err != nil {
return e, err
}
if err = e.serveMetrics(); err != nil {
return e, err
}
serving = true
return e, nil
}
// Config returns the current configuration.
func (e *Etcd) Config() Config {
return e.cfg
}
// Close gracefully shuts down all servers/listeners.
// Client requests will be terminated with request timeout.
// After timeout, enforce remaning requests be closed immediately.
func (e *Etcd) Close() {
e.closeOnce.Do(func() { close(e.stopc) })
// close client requests with request timeout
timeout := 2 * time.Second
if e.Server != nil {
timeout = e.Server.Cfg.ReqTimeout()
}
for _, sctx := range e.sctxs {
for ss := range sctx.serversC {
ctx, cancel := context.WithTimeout(context.Background(), timeout)
stopServers(ctx, ss)
cancel()
}
}
for _, sctx := range e.sctxs {
sctx.cancel()
}
for i := range e.Clients {
if e.Clients[i] != nil {
e.Clients[i].Close()
}
}
for i := range e.metricsListeners {
e.metricsListeners[i].Close()
}
// close rafthttp transports
if e.Server != nil {
e.Server.Stop()
}
// close all idle connections in peer handler (wait up to 1-second)
for i := range e.Peers {
if e.Peers[i] != nil && e.Peers[i].close != nil {
ctx, cancel := context.WithTimeout(context.Background(), time.Second)
e.Peers[i].close(ctx)
cancel()
}
}
}
func stopServers(ctx context.Context, ss *servers) {
shutdownNow := func() {
// first, close the http.Server
ss.http.Shutdown(ctx)
// then close grpc.Server; cancels all active RPCs
ss.grpc.Stop()
}
// do not grpc.Server.GracefulStop with TLS enabled etcd server
// See https://github.com/grpc/grpc-go/issues/1384#issuecomment-317124531
// and https://github.com/coreos/etcd/issues/8916
if ss.secure {
shutdownNow()
return
}
ch := make(chan struct{})
go func() {
defer close(ch)
// close listeners to stop accepting new connections,
// will block on any existing transports
ss.grpc.GracefulStop()
}()
// wait until all pending RPCs are finished
select {
case <-ch:
case <-ctx.Done():
// took too long, manually close open transports
// e.g. watch streams
shutdownNow()
// concurrent GracefulStop should be interrupted
<-ch
}
}
func (e *Etcd) Err() <-chan error { return e.errc }
func startPeerListeners(cfg *Config) (peers []*peerListener, err error) {
if err = updateCipherSuites(&cfg.PeerTLSInfo, cfg.CipherSuites); err != nil {
return nil, err
}
if err = cfg.PeerSelfCert(); err != nil {
plog.Fatalf("could not get certs (%v)", err)
}
if !cfg.PeerTLSInfo.Empty() {
plog.Infof("peerTLS: %s", cfg.PeerTLSInfo)
}
peers = make([]*peerListener, len(cfg.LPUrls))
defer func() {
if err == nil {
return
}
for i := range peers {
if peers[i] != nil && peers[i].close != nil {
plog.Info("stopping listening for peers on ", cfg.LPUrls[i].String())
ctx, cancel := context.WithTimeout(context.Background(), time.Second)
peers[i].close(ctx)
cancel()
}
}
}()
for i, u := range cfg.LPUrls {
if u.Scheme == "http" {
if !cfg.PeerTLSInfo.Empty() {
plog.Warningf("The scheme of peer url %s is HTTP while peer key/cert files are presented. Ignored peer key/cert files.", u.String())
}
if cfg.PeerTLSInfo.ClientCertAuth {
plog.Warningf("The scheme of peer url %s is HTTP while client cert auth (--peer-client-cert-auth) is enabled. Ignored client cert auth for this url.", u.String())
}
}
peers[i] = &peerListener{close: func(context.Context) error { return nil }}
peers[i].Listener, err = rafthttp.NewListener(u, &cfg.PeerTLSInfo)
if err != nil {
return nil, err
}
// once serve, overwrite with 'http.Server.Shutdown'
peers[i].close = func(context.Context) error {
return peers[i].Listener.Close()
}
plog.Info("listening for peers on ", u.String())
}
return peers, nil
}
// configure peer handlers after rafthttp.Transport started
func (e *Etcd) servePeers() (err error) {
ph := etcdhttp.NewPeerHandler(e.Server)
var peerTLScfg *tls.Config
if !e.cfg.PeerTLSInfo.Empty() {
if peerTLScfg, err = e.cfg.PeerTLSInfo.ServerConfig(); err != nil {
return err
}
}
for _, p := range e.Peers {
gs := v3rpc.Server(e.Server, peerTLScfg)
m := cmux.New(p.Listener)
go gs.Serve(m.Match(cmux.HTTP2()))
srv := &http.Server{
Handler: grpcHandlerFunc(gs, ph),
ReadTimeout: 5 * time.Minute,
ErrorLog: defaultLog.New(ioutil.Discard, "", 0), // do not log user error
}
go srv.Serve(m.Match(cmux.Any()))
p.serve = func() error { return m.Serve() }
p.close = func(ctx context.Context) error {
// gracefully shutdown http.Server
// close open listeners, idle connections
// until context cancel or time-out
stopServers(ctx, &servers{secure: peerTLScfg != nil, grpc: gs, http: srv})
return nil
}
}
// start peer servers in a goroutine
for _, pl := range e.Peers {
go func(l *peerListener) {
e.errHandler(l.serve())
}(pl)
}
return nil
}
func startClientListeners(cfg *Config) (sctxs map[string]*serveCtx, err error) {
if err = updateCipherSuites(&cfg.ClientTLSInfo, cfg.CipherSuites); err != nil {
return nil, err
}
if err = cfg.ClientSelfCert(); err != nil {
plog.Fatalf("could not get certs (%v)", err)
}
if cfg.EnablePprof {
plog.Infof("pprof is enabled under %s", debugutil.HTTPPrefixPProf)
}
sctxs = make(map[string]*serveCtx)
for _, u := range cfg.LCUrls {
sctx := newServeCtx()
if u.Scheme == "http" || u.Scheme == "unix" {
if !cfg.ClientTLSInfo.Empty() {
plog.Warningf("The scheme of client url %s is HTTP while peer key/cert files are presented. Ignored key/cert files.", u.String())
}
if cfg.ClientTLSInfo.ClientCertAuth {
plog.Warningf("The scheme of client url %s is HTTP while client cert auth (--client-cert-auth) is enabled. Ignored client cert auth for this url.", u.String())
}
}
if (u.Scheme == "https" || u.Scheme == "unixs") && cfg.ClientTLSInfo.Empty() {
return nil, fmt.Errorf("TLS key/cert (--cert-file, --key-file) must be provided for client url %s with HTTPs scheme", u.String())
}
proto := "tcp"
addr := u.Host
if u.Scheme == "unix" || u.Scheme == "unixs" {
proto = "unix"
addr = u.Host + u.Path
}
sctx.secure = u.Scheme == "https" || u.Scheme == "unixs"
sctx.insecure = !sctx.secure
if oldctx := sctxs[addr]; oldctx != nil {
oldctx.secure = oldctx.secure || sctx.secure
oldctx.insecure = oldctx.insecure || sctx.insecure
continue
}
if sctx.l, err = net.Listen(proto, addr); err != nil {
return nil, err
}
// net.Listener will rewrite ipv4 0.0.0.0 to ipv6 [::], breaking
// hosts that disable ipv6. So, use the address given by the user.
sctx.addr = addr
if fdLimit, fderr := runtimeutil.FDLimit(); fderr == nil {
if fdLimit <= reservedInternalFDNum {
plog.Fatalf("file descriptor limit[%d] of etcd process is too low, and should be set higher than %d to ensure internal usage", fdLimit, reservedInternalFDNum)
}
sctx.l = transport.LimitListener(sctx.l, int(fdLimit-reservedInternalFDNum))
}
if proto == "tcp" {
if sctx.l, err = transport.NewKeepAliveListener(sctx.l, "tcp", nil); err != nil {
return nil, err
}
}
plog.Info("listening for client requests on ", u.Host)
defer func() {
if err != nil {
sctx.l.Close()
plog.Info("stopping listening for client requests on ", u.Host)
}
}()
for k := range cfg.UserHandlers {
sctx.userHandlers[k] = cfg.UserHandlers[k]
}
sctx.serviceRegister = cfg.ServiceRegister
if cfg.EnablePprof || cfg.Debug {
sctx.registerPprof()
}
if cfg.Debug {
sctx.registerTrace()
}
sctxs[addr] = sctx
}
return sctxs, nil
}
func (e *Etcd) serveClients() (err error) {
if !e.cfg.ClientTLSInfo.Empty() {
plog.Infof("ClientTLS: %s", e.cfg.ClientTLSInfo)
}
if e.cfg.CorsInfo.String() != "" {
plog.Infof("cors = %s", e.cfg.CorsInfo)
}
// Start a client server goroutine for each listen address
var h http.Handler
if e.Config().EnableV2 {
if len(e.Config().ExperimentalEnableV2V3) > 0 {
srv := v2v3.NewServer(v3client.New(e.Server), e.cfg.ExperimentalEnableV2V3)
h = v2http.NewClientHandler(srv, e.Server.Cfg.ReqTimeout())
} else {
h = v2http.NewClientHandler(e.Server, e.Server.Cfg.ReqTimeout())
}
} else {
mux := http.NewServeMux()
etcdhttp.HandleBasic(mux, e.Server)
h = mux
}
h = http.Handler(&cors.CORSHandler{Handler: h, Info: e.cfg.CorsInfo})
gopts := []grpc.ServerOption{}
if e.cfg.GRPCKeepAliveMinTime > time.Duration(0) {
gopts = append(gopts, grpc.KeepaliveEnforcementPolicy(keepalive.EnforcementPolicy{
MinTime: e.cfg.GRPCKeepAliveMinTime,
PermitWithoutStream: false,
}))
}
if e.cfg.GRPCKeepAliveInterval > time.Duration(0) &&
e.cfg.GRPCKeepAliveTimeout > time.Duration(0) {
gopts = append(gopts, grpc.KeepaliveParams(keepalive.ServerParameters{
Time: e.cfg.GRPCKeepAliveInterval,
Timeout: e.cfg.GRPCKeepAliveTimeout,
}))
}
// start client servers in a goroutine
for _, sctx := range e.sctxs {
go func(s *serveCtx) {
e.errHandler(s.serve(e.Server, &e.cfg.ClientTLSInfo, h, e.errHandler, gopts...))
}(sctx)
}
return nil
}
func (e *Etcd) serveMetrics() (err error) {
if e.cfg.Metrics == "extensive" {
grpc_prometheus.EnableHandlingTimeHistogram()
}
if len(e.cfg.ListenMetricsUrls) > 0 {
metricsMux := http.NewServeMux()
etcdhttp.HandleMetricsHealth(metricsMux, e.Server)
for _, murl := range e.cfg.ListenMetricsUrls {
tlsInfo := &e.cfg.ClientTLSInfo
if murl.Scheme == "http" {
tlsInfo = nil
}
ml, err := transport.NewListener(murl.Host, murl.Scheme, tlsInfo)
if err != nil {
return err
}
e.metricsListeners = append(e.metricsListeners, ml)
go func(u url.URL, ln net.Listener) {
plog.Info("listening for metrics on ", u.String())
e.errHandler(http.Serve(ln, metricsMux))
}(murl, ml)
}
}
return nil
}
func (e *Etcd) errHandler(err error) {
select {
case <-e.stopc:
return
default:
}
select {
case <-e.stopc:
case e.errc <- err:
}
}
func parseCompactionRetention(mode, retention string) (ret time.Duration, err error) {
h, err := strconv.Atoi(retention)
if err == nil {
switch mode {
case compactor.ModeRevision:
ret = time.Duration(int64(h))
case compactor.ModePeriodic:
ret = time.Duration(int64(h)) * time.Hour
}
} else {
// periodic compaction
ret, err = time.ParseDuration(retention)
if err != nil {
return 0, fmt.Errorf("error parsing CompactionRetention: %v", err)
}
}
return ret, nil
}