etcd/etcdserver/cluster_util.go

124 lines
3.5 KiB
Go

// Copyright 2015 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 etcdserver
import (
"encoding/json"
"fmt"
"io/ioutil"
"log"
"net/http"
"sort"
"strconv"
"time"
"github.com/coreos/etcd/pkg/types"
)
// isMemberBootstrapped tries to check if the given member has been bootstrapped
// in the given cluster.
func isMemberBootstrapped(cl *Cluster, member string, tr *http.Transport) bool {
rcl, err := getClusterFromRemotePeers(getRemotePeerURLs(cl, member), false, tr)
if err != nil {
return false
}
id := cl.MemberByName(member).ID
m := rcl.Member(id)
if m == nil {
return false
}
if len(m.ClientURLs) > 0 {
return true
}
return false
}
// GetClusterFromRemotePeers takes a set of URLs representing etcd peers, and
// attempts to construct a Cluster by accessing the members endpoint on one of
// these URLs. The first URL to provide a response is used. If no URLs provide
// a response, or a Cluster cannot be successfully created from a received
// response, an error is returned.
func GetClusterFromRemotePeers(urls []string, tr *http.Transport) (*Cluster, error) {
return getClusterFromRemotePeers(urls, true, tr)
}
// If logerr is true, it prints out more error messages.
func getClusterFromRemotePeers(urls []string, logerr bool, tr *http.Transport) (*Cluster, error) {
cc := &http.Client{
Transport: tr,
Timeout: time.Second,
}
for _, u := range urls {
resp, err := cc.Get(u + "/members")
if err != nil {
if logerr {
log.Printf("etcdserver: could not get cluster response from %s: %v", u, err)
}
continue
}
b, err := ioutil.ReadAll(resp.Body)
if err != nil {
if logerr {
log.Printf("etcdserver: could not read the body of cluster response: %v", err)
}
continue
}
var membs []*Member
if err := json.Unmarshal(b, &membs); err != nil {
if logerr {
log.Printf("etcdserver: could not unmarshal cluster response: %v", err)
}
continue
}
id, err := types.IDFromString(resp.Header.Get("X-Etcd-Cluster-ID"))
if err != nil {
if logerr {
log.Printf("etcdserver: could not parse the cluster ID from cluster res: %v", err)
}
continue
}
var index uint64
// The header at or before v2.0.3 doesn't have this field. For backward
// compatibility, it checks whether the field exists.
if indexStr := resp.Header.Get("X-Raft-Index"); indexStr != "" {
index, err = strconv.ParseUint(indexStr, 10, 64)
if err != nil {
if logerr {
log.Printf("etcdserver: could not parse raft index: %v", err)
}
continue
}
}
cl := NewClusterFromMembers("", id, membs)
cl.UpdateIndex(index)
return cl, nil
}
return nil, fmt.Errorf("etcdserver: could not retrieve cluster information from the given urls")
}
// getRemotePeerURLs returns peer urls of remote members in the cluster. The
// returned list is sorted in ascending lexicographical order.
func getRemotePeerURLs(cl ClusterInfo, local string) []string {
us := make([]string, 0)
for _, m := range cl.Members() {
if m.Name == local {
continue
}
us = append(us, m.PeerURLs...)
}
sort.Strings(us)
return us
}