etcddb_server.go

package etcddb

import (
	"errors"
	"fmt"
	"net/url"
	"time"

	"github.com/singnet/snet-daemon/config"
	log "github.com/sirupsen/logrus"
	"github.com/spf13/viper"
	"go.etcd.io/etcd/embed"
)

// EtcdServer struct has some useful methods to wolrk with etcd server
type EtcdServer struct {
	conf *EtcdServerConf
	etcd *embed.Etcd
}

// IsEtcdServerEnabled checls that etcd server is enabled using conf file
func IsEtcdServerEnabled() (enabled bool, err error) {
	return IsEtcdServerEnabledInVip(config.Vip())
}

// IsEtcdServerEnabledInVip checls that etcd server is enabled using viper conf
func IsEtcdServerEnabledInVip(vip *viper.Viper) (enabled bool, err error) {

	conf, err := GetEtcdServerConf(vip)
	if err != nil {
		return
	}

	return conf.Enabled, nil
}

// GetEtcdServer returns EtcdServer in case it is defined in the viper config
// reuturns null if PAYMENT_CHANNEL_STORAGE property is not defined
// in the config file or the ENABLED field of the PAYMENT_CHANNEL_STORAGE
// is set to false
func GetEtcdServer() (server *EtcdServer, err error) {
	return GetEtcdServerFromVip(config.Vip())
}

// GetEtcdServerFromVip run etcd server using viper config
func GetEtcdServerFromVip(vip *viper.Viper) (server *EtcdServer, err error) {

	conf, err := GetEtcdServerConf(vip)

	log.WithField("PaymentChannelStorageServer", fmt.Sprintf("%+v", conf)).Info()

	if err != nil || conf == nil || !conf.Enabled {
		return
	}

	server = &EtcdServer{conf: conf}
	return
}

// Start starts etcd server
func (server *EtcdServer) Start() (err error) {

	etcd, err := startEtcdServer(server.conf)
	if err != nil {
		return
	}

	server.etcd = etcd
	return
}

// Close closes etcd server
func (server *EtcdServer) Close() {
	server.etcd.Close()
}

// StartEtcdServer starts ectd server
// The method blocks until the server is started
// or failed by timeout
func startEtcdServer(conf *EtcdServerConf) (etcd *embed.Etcd, err error) {

	etcdConf := getEtcdConf(conf)
	etcd, err = embed.StartEtcd(etcdConf)

	if err != nil {
		return
	}

	select {
	case <-etcd.Server.ReadyNotify():
	case <-time.After(conf.StartupTimeout):
		etcd.Server.Stop()
		return nil, errors.New("etcd server took too long to start: " + conf.ID)
	}

	return
}

func getEtcdConf(conf *EtcdServerConf) *embed.Config {

	clientURL := &url.URL{
		Scheme: conf.Scheme,
		Host:   fmt.Sprintf("%s:%d", conf.Host, conf.ClientPort),
	}

	peerURL := &url.URL{
		Scheme: conf.Scheme,
		Host:   fmt.Sprintf("%s:%d", conf.Host, conf.PeerPort),
	}

	log.WithField("PaymentChannelStorageServer", fmt.Sprintf("%+v", conf)).Info()
	log.WithField("ClientURL", clientURL).Info()
	log.WithField("PeerURL", peerURL).Info()

	etcdConf := embed.NewConfig()
	etcdConf.Name = conf.ID
	etcdConf.Dir = conf.DataDir

	// --listen-client-urls
	etcdConf.LCUrls = []url.URL{*clientURL}

	// --advertise-client-urls
	etcdConf.ACUrls = []url.URL{*clientURL}

	// --listen-peer-urls
	etcdConf.LPUrls = []url.URL{*peerURL}

	// --initial-advertise-peer-urls
	etcdConf.APUrls = []url.URL{*peerURL}

	// --initial-cluster
	etcdConf.InitialCluster = conf.Cluster

	//--initial-cluster-token
	etcdConf.InitialClusterToken = conf.Token

	//  --initial-cluster-state
	etcdConf.ClusterState = embed.ClusterStateFlagNew

	return etcdConf
}