forked from kubernetes/kubernetes
-
Notifications
You must be signed in to change notification settings - Fork 1
/
client.go
476 lines (400 loc) · 11.1 KB
/
client.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
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
package etcd
import (
"crypto/tls"
"crypto/x509"
"encoding/json"
"errors"
"io"
"io/ioutil"
"math/rand"
"net"
"net/http"
"net/url"
"os"
"path"
"strings"
"time"
)
// See SetConsistency for how to use these constants.
const (
// Using strings rather than iota because the consistency level
// could be persisted to disk, so it'd be better to use
// human-readable values.
STRONG_CONSISTENCY = "STRONG"
WEAK_CONSISTENCY = "WEAK"
)
const (
defaultBufferSize = 10
)
func init() {
rand.Seed(int64(time.Now().Nanosecond()))
}
type Config struct {
CertFile string `json:"certFile"`
KeyFile string `json:"keyFile"`
CaCertFile []string `json:"caCertFiles"`
DialTimeout time.Duration `json:"timeout"`
Consistency string `json:"consistency"`
}
type credentials struct {
username string
password string
}
type Client struct {
config Config `json:"config"`
cluster *Cluster `json:"cluster"`
httpClient *http.Client
credentials *credentials
transport *http.Transport
persistence io.Writer
cURLch chan string
// CheckRetry can be used to control the policy for failed requests
// and modify the cluster if needed.
// The client calls it before sending requests again, and
// stops retrying if CheckRetry returns some error. The cases that
// this function needs to handle include no response and unexpected
// http status code of response.
// If CheckRetry is nil, client will call the default one
// `DefaultCheckRetry`.
// Argument cluster is the etcd.Cluster object that these requests have been made on.
// Argument numReqs is the number of http.Requests that have been made so far.
// Argument lastResp is the http.Responses from the last request.
// Argument err is the reason of the failure.
CheckRetry func(cluster *Cluster, numReqs int,
lastResp http.Response, err error) error
}
// NewClient create a basic client that is configured to be used
// with the given machine list.
func NewClient(machines []string) *Client {
config := Config{
// default timeout is one second
DialTimeout: time.Second,
Consistency: WEAK_CONSISTENCY,
}
client := &Client{
cluster: NewCluster(machines),
config: config,
}
client.initHTTPClient()
client.saveConfig()
return client
}
// NewTLSClient create a basic client with TLS configuration
func NewTLSClient(machines []string, cert, key, caCert string) (*Client, error) {
// overwrite the default machine to use https
if len(machines) == 0 {
machines = []string{"https://127.0.0.1:4001"}
}
config := Config{
// default timeout is one second
DialTimeout: time.Second,
Consistency: WEAK_CONSISTENCY,
CertFile: cert,
KeyFile: key,
CaCertFile: make([]string, 0),
}
client := &Client{
cluster: NewCluster(machines),
config: config,
}
err := client.initHTTPSClient(cert, key)
if err != nil {
return nil, err
}
err = client.AddRootCA(caCert)
client.saveConfig()
return client, nil
}
// NewClientFromFile creates a client from a given file path.
// The given file is expected to use the JSON format.
func NewClientFromFile(fpath string) (*Client, error) {
fi, err := os.Open(fpath)
if err != nil {
return nil, err
}
defer func() {
if err := fi.Close(); err != nil {
panic(err)
}
}()
return NewClientFromReader(fi)
}
// NewClientFromReader creates a Client configured from a given reader.
// The configuration is expected to use the JSON format.
func NewClientFromReader(reader io.Reader) (*Client, error) {
c := new(Client)
b, err := ioutil.ReadAll(reader)
if err != nil {
return nil, err
}
err = json.Unmarshal(b, c)
if err != nil {
return nil, err
}
if c.config.CertFile == "" {
c.initHTTPClient()
} else {
err = c.initHTTPSClient(c.config.CertFile, c.config.KeyFile)
}
if err != nil {
return nil, err
}
for _, caCert := range c.config.CaCertFile {
if err := c.AddRootCA(caCert); err != nil {
return nil, err
}
}
return c, nil
}
// Override the Client's HTTP Transport object
func (c *Client) SetTransport(tr *http.Transport) {
c.httpClient.Transport = tr
c.transport = tr
}
func (c *Client) SetCredentials(username, password string) {
c.credentials = &credentials{username, password}
}
func (c *Client) Close() {
c.transport.DisableKeepAlives = true
c.transport.CloseIdleConnections()
}
// initHTTPClient initializes a HTTP client for etcd client
func (c *Client) initHTTPClient() {
c.transport = &http.Transport{
Dial: c.DefaultDial,
TLSClientConfig: &tls.Config{
InsecureSkipVerify: true,
},
}
c.httpClient = &http.Client{Transport: c.transport}
}
// initHTTPClient initializes a HTTPS client for etcd client
func (c *Client) initHTTPSClient(cert, key string) error {
if cert == "" || key == "" {
return errors.New("Require both cert and key path")
}
tlsCert, err := tls.LoadX509KeyPair(cert, key)
if err != nil {
return err
}
tlsConfig := &tls.Config{
Certificates: []tls.Certificate{tlsCert},
InsecureSkipVerify: true,
}
c.transport = &http.Transport{
TLSClientConfig: tlsConfig,
Dial: c.DefaultDial,
}
c.httpClient = &http.Client{Transport: c.transport}
return nil
}
// SetPersistence sets a writer to which the config will be
// written every time it's changed.
func (c *Client) SetPersistence(writer io.Writer) {
c.persistence = writer
}
// SetConsistency changes the consistency level of the client.
//
// When consistency is set to STRONG_CONSISTENCY, all requests,
// including GET, are sent to the leader. This means that, assuming
// the absence of leader failures, GET requests are guaranteed to see
// the changes made by previous requests.
//
// When consistency is set to WEAK_CONSISTENCY, other requests
// are still sent to the leader, but GET requests are sent to a
// random server from the server pool. This reduces the read
// load on the leader, but it's not guaranteed that the GET requests
// will see changes made by previous requests (they might have not
// yet been committed on non-leader servers).
func (c *Client) SetConsistency(consistency string) error {
if !(consistency == STRONG_CONSISTENCY || consistency == WEAK_CONSISTENCY) {
return errors.New("The argument must be either STRONG_CONSISTENCY or WEAK_CONSISTENCY.")
}
c.config.Consistency = consistency
return nil
}
// Sets the DialTimeout value
func (c *Client) SetDialTimeout(d time.Duration) {
c.config.DialTimeout = d
}
// AddRootCA adds a root CA cert for the etcd client
func (c *Client) AddRootCA(caCert string) error {
if c.httpClient == nil {
return errors.New("Client has not been initialized yet!")
}
certBytes, err := ioutil.ReadFile(caCert)
if err != nil {
return err
}
tr, ok := c.httpClient.Transport.(*http.Transport)
if !ok {
panic("AddRootCA(): Transport type assert should not fail")
}
if tr.TLSClientConfig.RootCAs == nil {
caCertPool := x509.NewCertPool()
ok = caCertPool.AppendCertsFromPEM(certBytes)
if ok {
tr.TLSClientConfig.RootCAs = caCertPool
}
tr.TLSClientConfig.InsecureSkipVerify = false
} else {
ok = tr.TLSClientConfig.RootCAs.AppendCertsFromPEM(certBytes)
}
if !ok {
err = errors.New("Unable to load caCert")
}
c.config.CaCertFile = append(c.config.CaCertFile, caCert)
c.saveConfig()
return err
}
// SetCluster updates cluster information using the given machine list.
func (c *Client) SetCluster(machines []string) bool {
success := c.internalSyncCluster(machines)
return success
}
func (c *Client) GetCluster() []string {
return c.cluster.Machines
}
// SyncCluster updates the cluster information using the internal machine list.
// If no members are found, the intenral machine list is left untouched.
func (c *Client) SyncCluster() bool {
return c.internalSyncCluster(c.cluster.Machines)
}
// internalSyncCluster syncs cluster information using the given machine list.
func (c *Client) internalSyncCluster(machines []string) bool {
// comma-separated list of machines in the cluster.
members := ""
for _, machine := range machines {
httpPath := c.createHttpPath(machine, path.Join(version, "members"))
resp, err := c.httpClient.Get(httpPath)
if err != nil {
// try another machine in the cluster
continue
}
if resp.StatusCode != http.StatusOK { // fall-back to old endpoint
httpPath := c.createHttpPath(machine, path.Join(version, "machines"))
resp, err := c.httpClient.Get(httpPath)
if err != nil {
// try another machine in the cluster
continue
}
b, err := ioutil.ReadAll(resp.Body)
resp.Body.Close()
if err != nil {
// try another machine in the cluster
continue
}
members = string(b)
} else {
b, err := ioutil.ReadAll(resp.Body)
resp.Body.Close()
if err != nil {
// try another machine in the cluster
continue
}
var mCollection memberCollection
if err := json.Unmarshal(b, &mCollection); err != nil {
// try another machine
continue
}
urls := make([]string, 0)
for _, m := range mCollection {
urls = append(urls, m.ClientURLs...)
}
members = strings.Join(urls, ",")
}
// We should never do an empty cluster update.
if members == "" {
continue
}
// update Machines List
c.cluster.updateFromStr(members)
logger.Debug("sync.machines ", c.cluster.Machines)
c.saveConfig()
return true
}
return false
}
// createHttpPath creates a complete HTTP URL.
// serverName should contain both the host name and a port number, if any.
func (c *Client) createHttpPath(serverName string, _path string) string {
u, err := url.Parse(serverName)
if err != nil {
panic(err)
}
u.Path = path.Join(u.Path, _path)
if u.Scheme == "" {
u.Scheme = "http"
}
return u.String()
}
// DefaultDial attempts to open a TCP connection to the provided address, explicitly
// enabling keep-alives with a one-second interval.
func (c *Client) DefaultDial(network, addr string) (net.Conn, error) {
dialer := net.Dialer{
Timeout: c.config.DialTimeout,
KeepAlive: time.Second,
}
return dialer.Dial(network, addr)
}
func (c *Client) OpenCURL() {
c.cURLch = make(chan string, defaultBufferSize)
}
func (c *Client) CloseCURL() {
c.cURLch = nil
}
func (c *Client) sendCURL(command string) {
go func() {
select {
case c.cURLch <- command:
default:
}
}()
}
func (c *Client) RecvCURL() string {
return <-c.cURLch
}
// saveConfig saves the current config using c.persistence.
func (c *Client) saveConfig() error {
if c.persistence != nil {
b, err := json.Marshal(c)
if err != nil {
return err
}
_, err = c.persistence.Write(b)
if err != nil {
return err
}
}
return nil
}
// MarshalJSON implements the Marshaller interface
// as defined by the standard JSON package.
func (c *Client) MarshalJSON() ([]byte, error) {
b, err := json.Marshal(struct {
Config Config `json:"config"`
Cluster *Cluster `json:"cluster"`
}{
Config: c.config,
Cluster: c.cluster,
})
if err != nil {
return nil, err
}
return b, nil
}
// UnmarshalJSON implements the Unmarshaller interface
// as defined by the standard JSON package.
func (c *Client) UnmarshalJSON(b []byte) error {
temp := struct {
Config Config `json:"config"`
Cluster *Cluster `json:"cluster"`
}{}
err := json.Unmarshal(b, &temp)
if err != nil {
return err
}
c.cluster = temp.Cluster
c.config = temp.Config
return nil
}