forked from etcd-io/etcd
-
Notifications
You must be signed in to change notification settings - Fork 0
/
cluster_util.go
263 lines (246 loc) · 8.04 KB
/
cluster_util.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
// 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"
"net/http"
"sort"
"time"
"github.com/coreos/etcd/Godeps/_workspace/src/github.com/coreos/go-semver/semver"
"github.com/coreos/etcd/pkg/types"
"github.com/coreos/etcd/version"
)
// 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 {
plog.Warningf("could not get cluster response from %s: %v", u, err)
}
continue
}
b, err := ioutil.ReadAll(resp.Body)
if err != nil {
if logerr {
plog.Warningf("could not read the body of cluster response: %v", err)
}
continue
}
var membs []*Member
if err := json.Unmarshal(b, &membs); err != nil {
if logerr {
plog.Warningf("could not unmarshal cluster response: %v", err)
}
continue
}
id, err := types.IDFromString(resp.Header.Get("X-Etcd-Cluster-ID"))
if err != nil {
if logerr {
plog.Warningf("could not parse the cluster ID from cluster res: %v", err)
}
continue
}
return newClusterFromMembers("", id, membs), nil
}
return nil, fmt.Errorf("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 Cluster, 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
}
// getVersions returns the versions of the members in the given cluster.
// The key of the returned map is the member's ID. The value of the returned map
// is the semver versions string, including server and cluster.
// If it fails to get the version of a member, the key will be nil.
func getVersions(cl Cluster, local types.ID, tr *http.Transport) map[string]*version.Versions {
members := cl.Members()
vers := make(map[string]*version.Versions)
for _, m := range members {
if m.ID == local {
cv := "not_decided"
if cl.Version() != nil {
cv = cl.Version().String()
}
vers[m.ID.String()] = &version.Versions{Server: version.Version, Cluster: cv}
continue
}
ver, err := getVersion(m, tr)
if err != nil {
plog.Warningf("cannot get the version of member %s (%v)", m.ID, err)
vers[m.ID.String()] = nil
} else {
vers[m.ID.String()] = ver
}
}
return vers
}
// decideClusterVersion decides the cluster version based on the versions map.
// The returned version is the min server version in the map, or nil if the min
// version in unknown.
func decideClusterVersion(vers map[string]*version.Versions) *semver.Version {
var cv *semver.Version
lv := semver.Must(semver.NewVersion(version.Version))
for mid, ver := range vers {
if ver == nil {
return nil
}
v, err := semver.NewVersion(ver.Server)
if err != nil {
plog.Errorf("cannot understand the version of member %s (%v)", mid, err)
return nil
}
if lv.LessThan(*v) {
plog.Warningf("the local etcd version %s is not up-to-date", lv.String())
plog.Warningf("member %s has a higher version %s", mid, ver.Server)
}
if cv == nil {
cv = v
} else if v.LessThan(*cv) {
cv = v
}
}
return cv
}
// isCompatibleWithCluster return true if the local member has a compitable version with
// the current running cluster.
// The version is considered as compitable when at least one of the other members in the cluster has a
// cluster version in the range of [MinClusterVersion, Version] and no known members has a cluster version
// out of the range.
// We set this rule since when the local member joins, another member might be offline.
func isCompatibleWithCluster(cl Cluster, local types.ID, tr *http.Transport) bool {
vers := getVersions(cl, local, tr)
minV := semver.Must(semver.NewVersion(version.MinClusterVersion))
maxV := semver.Must(semver.NewVersion(version.Version))
maxV = &semver.Version{
Major: maxV.Major,
Minor: maxV.Minor,
}
return isCompatibleWithVers(vers, local, minV, maxV)
}
func isCompatibleWithVers(vers map[string]*version.Versions, local types.ID, minV, maxV *semver.Version) bool {
var ok bool
for id, v := range vers {
// ignore comparasion with local version
if id == local.String() {
continue
}
if v == nil {
continue
}
clusterv, err := semver.NewVersion(v.Cluster)
if err != nil {
plog.Errorf("cannot understand the cluster version of member %s (%v)", id, err)
continue
}
if clusterv.LessThan(*minV) {
plog.Warningf("the running cluster version(%v) is lower than the minimal cluster version(%v) supported", clusterv.String(), minV.String())
return false
}
if maxV.LessThan(*clusterv) {
plog.Warningf("the running cluster version(%v) is higher than the maximum cluster version(%v) supported", clusterv.String(), maxV.String())
return false
}
ok = true
}
return ok
}
// getVersion returns the Versions of the given member via its
// peerURLs. Returns the last error if it fails to get the version.
func getVersion(m *Member, tr *http.Transport) (*version.Versions, error) {
cc := &http.Client{
Transport: tr,
}
var (
err error
resp *http.Response
)
for _, u := range m.PeerURLs {
resp, err = cc.Get(u + "/version")
if err != nil {
plog.Warningf("failed to reach the peerURL(%s) of member %s (%v)", u, m.ID, err)
continue
}
// etcd 2.0 does not have version endpoint on peer url.
if resp.StatusCode == http.StatusNotFound {
resp.Body.Close()
return &version.Versions{
Server: "2.0.0",
Cluster: "2.0.0",
}, nil
}
var b []byte
b, err = ioutil.ReadAll(resp.Body)
resp.Body.Close()
if err != nil {
plog.Warningf("failed to read out the response body from the peerURL(%s) of member %s (%v)", u, m.ID, err)
continue
}
var vers version.Versions
if err := json.Unmarshal(b, &vers); err != nil {
plog.Warningf("failed to unmarshal the response body got from the peerURL(%s) of member %s (%v)", u, m.ID, err)
continue
}
return &vers, nil
}
return nil, err
}
func MustDetectDowngrade(cv *semver.Version) {
lv := semver.Must(semver.NewVersion(version.Version))
// only keep major.minor version for comparison against cluster version
lv = &semver.Version{Major: lv.Major, Minor: lv.Minor}
if cv != nil && lv.LessThan(*cv) {
plog.Fatalf("cluster cannot be downgraded (current version: %s is lower than determined cluster version: %s).", version.Version, version.Cluster(cv.String()))
}
}