syncer/etcd/agent.go

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 (
	"errors"
	"github.com/apache/servicecomb-service-center/pkg/log"
	"github.com/apache/servicecomb-service-center/syncer/servicecenter"
	"github.com/coreos/etcd/embed"
	"github.com/coreos/etcd/etcdserver/api/v3client"
)

// Agent warps the embed etcd
type Agent struct {
	conf    *Config
	etcd    *embed.Etcd
	storage servicecenter.Storage
}

// NewAgent new etcd agent with config
func NewAgent(conf *Config) *Agent {
	return &Agent{conf: conf}
}

// Run etcd agent
func (a *Agent) Run() error {
	etcd, err := embed.StartEtcd(a.conf.Config)
	if err != nil {
		return err
	}
	select {
	// Be returns when the server is readied
	case <-etcd.Server.ReadyNotify():
		log.Info("ready notify")

	// Be returns when the server is stopped
	case <-etcd.Server.StopNotify():
		err := errors.New("unknown error cause start etcd failed, check etcd")
		log.Error("stop notify", err)
		return err

	case err = <-etcd.Err():
		log.Error("start etcd failed", err)
		return err
	}
	a.etcd = etcd
	return nil
}

// Storage returns etcd storage
func (a *Agent) Storage() servicecenter.Storage {
	if a.storage == nil {
		a.storage = NewStorage(v3client.New(a.etcd.Server))
	}
	return a.storage
}

// Stop etcd agent
func (a *Agent) Stop() {
	a.etcd.Close()
}