config.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 (
"fmt"
"io/ioutil"
"net"
"net/http"
"net/url"
"strings"
"time"
"github.com/coreos/etcd/etcdserver"
"github.com/coreos/etcd/pkg/cors"
"github.com/coreos/etcd/pkg/netutil"
"github.com/coreos/etcd/pkg/srv"
"github.com/coreos/etcd/pkg/transport"
"github.com/coreos/etcd/pkg/types"
"github.com/ghodss/yaml"
"google.golang.org/grpc"
)
const (
ClusterStateFlagNew = "new"
ClusterStateFlagExisting = "existing"
DefaultName = "default"
DefaultMaxSnapshots = 5
DefaultMaxWALs = 5
DefaultMaxRequestBytes = 1.5 * 1024 * 1024
DefaultGRPCKeepAliveMinTime = 5 * time.Second
DefaultGRPCKeepAliveInterval = 2 * time.Hour
DefaultGRPCKeepAliveTimeout = 20 * time.Second
DefaultListenPeerURLs = "http://localhost:2380"
DefaultListenClientURLs = "http://localhost:2379"
// maxElectionMs specifies the maximum value of election timeout.
// More details are listed in ../Documentation/tuning.md#time-parameters.
maxElectionMs = 50000
)
var (
ErrConflictBootstrapFlags = fmt.Errorf("multiple discovery or bootstrap flags are set. " +
"Choose one of \"initial-cluster\", \"discovery\" or \"discovery-srv\"")
ErrUnsetAdvertiseClientURLsFlag = fmt.Errorf("--advertise-client-urls is required when --listen-client-urls is set explicitly")
DefaultInitialAdvertisePeerURLs = "http://localhost:2380"
DefaultAdvertiseClientURLs = "http://localhost:2379"
defaultHostname string
defaultHostStatus error
)
func init() {
defaultHostname, defaultHostStatus = netutil.GetDefaultHost()
}
// Config holds the arguments for configuring an etcd server.
type Config struct {
// member
CorsInfo *cors.CORSInfo
LPUrls, LCUrls []url.URL
Dir string `json:"data-dir"`
WalDir string `json:"wal-dir"`
MaxSnapFiles uint `json:"max-snapshots"`
MaxWalFiles uint `json:"max-wals"`
Name string `json:"name"`
SnapCount uint64 `json:"snapshot-count"`
AutoCompactionRetention int `json:"auto-compaction-retention"`
// TickMs is the number of milliseconds between heartbeat ticks.
// TODO: decouple tickMs and heartbeat tick (current heartbeat tick = 1).
// make ticks a cluster wide configuration.
TickMs uint `json:"heartbeat-interval"`
ElectionMs uint `json:"election-timeout"`
// InitialElectionTickAdvance is true, then local member fast-forwards
// election ticks to speed up "initial" leader election trigger. This
// benefits the case of larger election ticks. For instance, cross
// datacenter deployment may require longer election timeout of 10-second.
// If true, local node does not need wait up to 10-second. Instead,
// forwards its election ticks to 8-second, and have only 2-second left
// before leader election.
//
// Major assumptions are that:
// - cluster has no active leader thus advancing ticks enables faster
// leader election, or
// - cluster already has an established leader, and rejoining follower
// is likely to receive heartbeats from the leader after tick advance
// and before election timeout.
//
// However, when network from leader to rejoining follower is congested,
// and the follower does not receive leader heartbeat within left election
// ticks, disruptive election has to happen thus affecting cluster
// availabilities.
//
// Disabling this would slow down initial bootstrap process for cross
// datacenter deployments. Make your own tradeoffs by configuring
// --initial-election-tick-advance at the cost of slow initial bootstrap.
//
// If single-node, it advances ticks regardless.
//
// See https://github.com/coreos/etcd/issues/9333 for more detail.
InitialElectionTickAdvance bool `json:"initial-election-tick-advance"`
QuotaBackendBytes int64 `json:"quota-backend-bytes"`
MaxRequestBytes uint `json:"max-request-bytes"`
// gRPC server options
// GRPCKeepAliveMinTime is the minimum interval that a client should
// wait before pinging server. When client pings "too fast", server
// sends goaway and closes the connection (errors: too_many_pings,
// http2.ErrCodeEnhanceYourCalm). When too slow, nothing happens.
// Server expects client pings only when there is any active streams
// (PermitWithoutStream is set false).
GRPCKeepAliveMinTime time.Duration `json:"grpc-keepalive-min-time"`
// GRPCKeepAliveInterval is the frequency of server-to-client ping
// to check if a connection is alive. Close a non-responsive connection
// after an additional duration of Timeout. 0 to disable.
GRPCKeepAliveInterval time.Duration `json:"grpc-keepalive-interval"`
// GRPCKeepAliveTimeout is the additional duration of wait
// before closing a non-responsive connection. 0 to disable.
GRPCKeepAliveTimeout time.Duration `json:"grpc-keepalive-timeout"`
// clustering
APUrls, ACUrls []url.URL
ClusterState string `json:"initial-cluster-state"`
DNSCluster string `json:"discovery-srv"`
Dproxy string `json:"discovery-proxy"`
Durl string `json:"discovery"`
InitialCluster string `json:"initial-cluster"`
InitialClusterToken string `json:"initial-cluster-token"`
StrictReconfigCheck bool `json:"strict-reconfig-check"`
EnableV2 bool `json:"enable-v2"`
// security
ClientTLSInfo transport.TLSInfo
ClientAutoTLS bool
PeerTLSInfo transport.TLSInfo
PeerAutoTLS bool
// debug
Debug bool `json:"debug"`
LogPkgLevels string `json:"log-package-levels"`
EnablePprof bool `json:"enable-pprof"`
Metrics string `json:"metrics"`
// ForceNewCluster starts a new cluster even if previously started; unsafe.
ForceNewCluster bool `json:"force-new-cluster"`
// UserHandlers is for registering users handlers and only used for
// embedding etcd into other applications.
// The map key is the route path for the handler, and
// you must ensure it can't be conflicted with etcd's.
UserHandlers map[string]http.Handler `json:"-"`
// ServiceRegister is for registering users' gRPC services. A simple usage example:
// cfg := embed.NewConfig()
// cfg.ServerRegister = func(s *grpc.Server) {
// pb.RegisterFooServer(s, &fooServer{})
// pb.RegisterBarServer(s, &barServer{})
// }
// embed.StartEtcd(cfg)
ServiceRegister func(*grpc.Server) `json:"-"`
// auth
AuthToken string `json:"auth-token"`
}
// configYAML holds the config suitable for yaml parsing
type configYAML struct {
Config
configJSON
}
// configJSON has file options that are translated into Config options
type configJSON struct {
LPUrlsJSON string `json:"listen-peer-urls"`
LCUrlsJSON string `json:"listen-client-urls"`
CorsJSON string `json:"cors"`
APUrlsJSON string `json:"initial-advertise-peer-urls"`
ACUrlsJSON string `json:"advertise-client-urls"`
ClientSecurityJSON securityConfig `json:"client-transport-security"`
PeerSecurityJSON securityConfig `json:"peer-transport-security"`
}
type securityConfig struct {
CAFile string `json:"ca-file"`
CertFile string `json:"cert-file"`
KeyFile string `json:"key-file"`
CertAuth bool `json:"client-cert-auth"`
TrustedCAFile string `json:"trusted-ca-file"`
AutoTLS bool `json:"auto-tls"`
}
// NewConfig creates a new Config populated with default values.
func NewConfig() *Config {
lpurl, _ := url.Parse(DefaultListenPeerURLs)
apurl, _ := url.Parse(DefaultInitialAdvertisePeerURLs)
lcurl, _ := url.Parse(DefaultListenClientURLs)
acurl, _ := url.Parse(DefaultAdvertiseClientURLs)
cfg := &Config{
CorsInfo: &cors.CORSInfo{},
MaxSnapFiles: DefaultMaxSnapshots,
MaxWalFiles: DefaultMaxWALs,
Name: DefaultName,
SnapCount: etcdserver.DefaultSnapCount,
MaxRequestBytes: DefaultMaxRequestBytes,
GRPCKeepAliveMinTime: DefaultGRPCKeepAliveMinTime,
GRPCKeepAliveInterval: DefaultGRPCKeepAliveInterval,
GRPCKeepAliveTimeout: DefaultGRPCKeepAliveTimeout,
TickMs: 100,
ElectionMs: 1000,
InitialElectionTickAdvance: true,
LPUrls: []url.URL{*lpurl},
LCUrls: []url.URL{*lcurl},
APUrls: []url.URL{*apurl},
ACUrls: []url.URL{*acurl},
ClusterState: ClusterStateFlagNew,
InitialClusterToken: "etcd-cluster",
StrictReconfigCheck: true,
Metrics: "basic",
EnableV2: true,
AuthToken: "simple",
}
cfg.InitialCluster = cfg.InitialClusterFromName(cfg.Name)
return cfg
}
func ConfigFromFile(path string) (*Config, error) {
cfg := &configYAML{Config: *NewConfig()}
if err := cfg.configFromFile(path); err != nil {
return nil, err
}
return &cfg.Config, nil
}
func (cfg *configYAML) configFromFile(path string) error {
b, err := ioutil.ReadFile(path)
if err != nil {
return err
}
defaultInitialCluster := cfg.InitialCluster
err = yaml.Unmarshal(b, cfg)
if err != nil {
return err
}
if cfg.LPUrlsJSON != "" {
u, err := types.NewURLs(strings.Split(cfg.LPUrlsJSON, ","))
if err != nil {
plog.Fatalf("unexpected error setting up listen-peer-urls: %v", err)
}
cfg.LPUrls = []url.URL(u)
}
if cfg.LCUrlsJSON != "" {
u, err := types.NewURLs(strings.Split(cfg.LCUrlsJSON, ","))
if err != nil {
plog.Fatalf("unexpected error setting up listen-client-urls: %v", err)
}
cfg.LCUrls = []url.URL(u)
}
if cfg.CorsJSON != "" {
if err := cfg.CorsInfo.Set(cfg.CorsJSON); err != nil {
plog.Panicf("unexpected error setting up cors: %v", err)
}
}
if cfg.APUrlsJSON != "" {
u, err := types.NewURLs(strings.Split(cfg.APUrlsJSON, ","))
if err != nil {
plog.Fatalf("unexpected error setting up initial-advertise-peer-urls: %v", err)
}
cfg.APUrls = []url.URL(u)
}
if cfg.ACUrlsJSON != "" {
u, err := types.NewURLs(strings.Split(cfg.ACUrlsJSON, ","))
if err != nil {
plog.Fatalf("unexpected error setting up advertise-peer-urls: %v", err)
}
cfg.ACUrls = []url.URL(u)
}
// If a discovery flag is set, clear default initial cluster set by InitialClusterFromName
if (cfg.Durl != "" || cfg.DNSCluster != "") && cfg.InitialCluster == defaultInitialCluster {
cfg.InitialCluster = ""
}
if cfg.ClusterState == "" {
cfg.ClusterState = ClusterStateFlagNew
}
copySecurityDetails := func(tls *transport.TLSInfo, ysc *securityConfig) {
tls.CAFile = ysc.CAFile
tls.CertFile = ysc.CertFile
tls.KeyFile = ysc.KeyFile
tls.ClientCertAuth = ysc.CertAuth
tls.TrustedCAFile = ysc.TrustedCAFile
}
copySecurityDetails(&cfg.ClientTLSInfo, &cfg.ClientSecurityJSON)
copySecurityDetails(&cfg.PeerTLSInfo, &cfg.PeerSecurityJSON)
cfg.ClientAutoTLS = cfg.ClientSecurityJSON.AutoTLS
cfg.PeerAutoTLS = cfg.PeerSecurityJSON.AutoTLS
return cfg.Validate()
}
func (cfg *Config) Validate() error {
if err := checkBindURLs(cfg.LPUrls); err != nil {
return err
}
if err := checkBindURLs(cfg.LCUrls); err != nil {
return err
}
// Check if conflicting flags are passed.
nSet := 0
for _, v := range []bool{cfg.Durl != "", cfg.InitialCluster != "", cfg.DNSCluster != ""} {
if v {
nSet++
}
}
if cfg.ClusterState != ClusterStateFlagNew && cfg.ClusterState != ClusterStateFlagExisting {
return fmt.Errorf("unexpected clusterState %q", cfg.ClusterState)
}
if nSet > 1 {
return ErrConflictBootstrapFlags
}
if 5*cfg.TickMs > cfg.ElectionMs {
return fmt.Errorf("--election-timeout[%vms] should be at least as 5 times as --heartbeat-interval[%vms]", cfg.ElectionMs, cfg.TickMs)
}
if cfg.ElectionMs > maxElectionMs {
return fmt.Errorf("--election-timeout[%vms] is too long, and should be set less than %vms", cfg.ElectionMs, maxElectionMs)
}
// check this last since proxying in etcdmain may make this OK
if cfg.LCUrls != nil && cfg.ACUrls == nil {
return ErrUnsetAdvertiseClientURLsFlag
}
return nil
}
// PeerURLsMapAndToken sets up an initial peer URLsMap and cluster token for bootstrap or discovery.
func (cfg *Config) PeerURLsMapAndToken(which string) (urlsmap types.URLsMap, token string, err error) {
token = cfg.InitialClusterToken
switch {
case cfg.Durl != "":
urlsmap = types.URLsMap{}
// If using discovery, generate a temporary cluster based on
// self's advertised peer URLs
urlsmap[cfg.Name] = cfg.APUrls
token = cfg.Durl
case cfg.DNSCluster != "":
clusterStrs, cerr := srv.GetCluster("etcd-server", cfg.Name, cfg.DNSCluster, cfg.APUrls)
if cerr != nil {
plog.Errorf("couldn't resolve during SRV discovery (%v)", cerr)
return nil, "", cerr
}
for _, s := range clusterStrs {
plog.Noticef("got bootstrap from DNS for etcd-server at %s", s)
}
clusterStr := strings.Join(clusterStrs, ",")
if strings.Contains(clusterStr, "https://") && cfg.PeerTLSInfo.CAFile == "" {
cfg.PeerTLSInfo.ServerName = cfg.DNSCluster
}
urlsmap, err = types.NewURLsMap(clusterStr)
// only etcd member must belong to the discovered cluster.
// proxy does not need to belong to the discovered cluster.
if which == "etcd" {
if _, ok := urlsmap[cfg.Name]; !ok {
return nil, "", fmt.Errorf("cannot find local etcd member %q in SRV records", cfg.Name)
}
}
default:
// We're statically configured, and cluster has appropriately been set.
urlsmap, err = types.NewURLsMap(cfg.InitialCluster)
}
return urlsmap, token, err
}
func (cfg Config) InitialClusterFromName(name string) (ret string) {
if len(cfg.APUrls) == 0 {
return ""
}
n := name
if name == "" {
n = DefaultName
}
for i := range cfg.APUrls {
ret = ret + "," + n + "=" + cfg.APUrls[i].String()
}
return ret[1:]
}
func (cfg Config) IsNewCluster() bool { return cfg.ClusterState == ClusterStateFlagNew }
func (cfg Config) ElectionTicks() int { return int(cfg.ElectionMs / cfg.TickMs) }
func (cfg Config) defaultPeerHost() bool {
return len(cfg.APUrls) == 1 && cfg.APUrls[0].String() == DefaultInitialAdvertisePeerURLs
}
func (cfg Config) defaultClientHost() bool {
return len(cfg.ACUrls) == 1 && cfg.ACUrls[0].String() == DefaultAdvertiseClientURLs
}
// UpdateDefaultClusterFromName updates cluster advertise URLs with, if available, default host,
// if advertise URLs are default values(localhost:2379,2380) AND if listen URL is 0.0.0.0.
// e.g. advertise peer URL localhost:2380 or listen peer URL 0.0.0.0:2380
// then the advertise peer host would be updated with machine's default host,
// while keeping the listen URL's port.
// User can work around this by explicitly setting URL with 127.0.0.1.
// It returns the default hostname, if used, and the error, if any, from getting the machine's default host.
// TODO: check whether fields are set instead of whether fields have default value
func (cfg *Config) UpdateDefaultClusterFromName(defaultInitialCluster string) (string, error) {
if defaultHostname == "" || defaultHostStatus != nil {
// update 'initial-cluster' when only the name is specified (e.g. 'etcd --name=abc')
if cfg.Name != DefaultName && cfg.InitialCluster == defaultInitialCluster {
cfg.InitialCluster = cfg.InitialClusterFromName(cfg.Name)
}
return "", defaultHostStatus
}
used := false
pip, pport := cfg.LPUrls[0].Hostname(), cfg.LPUrls[0].Port()
if cfg.defaultPeerHost() && pip == "0.0.0.0" {
cfg.APUrls[0] = url.URL{Scheme: cfg.APUrls[0].Scheme, Host: fmt.Sprintf("%s:%s", defaultHostname, pport)}
used = true
}
// update 'initial-cluster' when only the name is specified (e.g. 'etcd --name=abc')
if cfg.Name != DefaultName && cfg.InitialCluster == defaultInitialCluster {
cfg.InitialCluster = cfg.InitialClusterFromName(cfg.Name)
}
cip, cport := cfg.LCUrls[0].Hostname(), cfg.LCUrls[0].Port()
if cfg.defaultClientHost() && cip == "0.0.0.0" {
cfg.ACUrls[0] = url.URL{Scheme: cfg.ACUrls[0].Scheme, Host: fmt.Sprintf("%s:%s", defaultHostname, cport)}
used = true
}
dhost := defaultHostname
if !used {
dhost = ""
}
return dhost, defaultHostStatus
}
// checkBindURLs returns an error if any URL uses a domain name.
// TODO: return error in 3.2.0
func checkBindURLs(urls []url.URL) error {
for _, url := range urls {
if url.Scheme == "unix" || url.Scheme == "unixs" {
continue
}
host, _, err := net.SplitHostPort(url.Host)
if err != nil {
return err
}
if host == "localhost" {
// special case for local address
// TODO: support /etc/hosts ?
continue
}
if net.ParseIP(host) == nil {
return fmt.Errorf("expected IP in URL for binding (%s)", url.String())
}
}
return nil
}
