forked from etcd-io/etcd
-
Notifications
You must be signed in to change notification settings - Fork 0
/
keys.go
288 lines (239 loc) · 6.45 KB
/
keys.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
/*
Copyright 2014 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 client
import (
"encoding/json"
"errors"
"fmt"
"net/http"
"net/url"
"path"
"strconv"
"strings"
"time"
"github.com/coreos/etcd/Godeps/_workspace/src/golang.org/x/net/context"
)
var (
DefaultV2KeysPrefix = "/v2/keys"
)
var (
ErrUnavailable = errors.New("client: no available etcd endpoints")
ErrNoLeader = errors.New("client: no leader")
ErrKeyNoExist = errors.New("client: key does not exist")
ErrKeyExists = errors.New("client: key already exists")
)
func NewKeysAPI(c HTTPClient) KeysAPI {
return &httpKeysAPI{
client: c,
prefix: DefaultV2KeysPrefix,
}
}
func NewDiscoveryKeysAPI(c HTTPClient) KeysAPI {
return &httpKeysAPI{
client: c,
prefix: "",
}
}
type KeysAPI interface {
Create(ctx context.Context, key, value string, ttl time.Duration) (*Response, error)
Get(ctx context.Context, key string) (*Response, error)
Watch(key string, idx uint64) Watcher
RecursiveWatch(key string, idx uint64) Watcher
}
type Watcher interface {
Next(context.Context) (*Response, error)
}
type Response struct {
Action string `json:"action"`
Node *Node `json:"node"`
PrevNode *Node `json:"prevNode"`
Index uint64
}
type Nodes []*Node
type Node struct {
Key string `json:"key"`
Value string `json:"value"`
Nodes Nodes `json:"nodes"`
ModifiedIndex uint64 `json:"modifiedIndex"`
CreatedIndex uint64 `json:"createdIndex"`
}
func (n *Node) String() string {
return fmt.Sprintf("{Key: %s, CreatedIndex: %d, ModifiedIndex: %d}", n.Key, n.CreatedIndex, n.ModifiedIndex)
}
type httpKeysAPI struct {
client HTTPClient
prefix string
}
func (k *httpKeysAPI) Create(ctx context.Context, key, val string, ttl time.Duration) (*Response, error) {
create := &createAction{
Prefix: k.prefix,
Key: key,
Value: val,
}
if ttl >= 0 {
uttl := uint64(ttl.Seconds())
create.TTL = &uttl
}
resp, body, err := k.client.Do(ctx, create)
if err != nil {
return nil, err
}
return unmarshalHTTPResponse(resp.StatusCode, resp.Header, body)
}
func (k *httpKeysAPI) Get(ctx context.Context, key string) (*Response, error) {
get := &getAction{
Prefix: k.prefix,
Key: key,
Recursive: false,
}
resp, body, err := k.client.Do(ctx, get)
if err != nil {
return nil, err
}
return unmarshalHTTPResponse(resp.StatusCode, resp.Header, body)
}
func (k *httpKeysAPI) Watch(key string, idx uint64) Watcher {
return &httpWatcher{
client: k.client,
nextWait: waitAction{
Prefix: k.prefix,
Key: key,
WaitIndex: idx,
Recursive: false,
},
}
}
func (k *httpKeysAPI) RecursiveWatch(key string, idx uint64) Watcher {
return &httpWatcher{
client: k.client,
nextWait: waitAction{
Prefix: k.prefix,
Key: key,
WaitIndex: idx,
Recursive: true,
},
}
}
type httpWatcher struct {
client HTTPClient
nextWait waitAction
}
func (hw *httpWatcher) Next(ctx context.Context) (*Response, error) {
httpresp, body, err := hw.client.Do(ctx, &hw.nextWait)
if err != nil {
return nil, err
}
resp, err := unmarshalHTTPResponse(httpresp.StatusCode, httpresp.Header, body)
if err != nil {
return nil, err
}
hw.nextWait.WaitIndex = resp.Node.ModifiedIndex + 1
return resp, nil
}
// v2KeysURL forms a URL representing the location of a key.
// The endpoint argument represents the base URL of an etcd
// server. The prefix is the path needed to route from the
// provided endpoint's path to the root of the keys API
// (typically "/v2/keys").
func v2KeysURL(ep url.URL, prefix, key string) *url.URL {
ep.Path = path.Join(ep.Path, prefix, key)
return &ep
}
type getAction struct {
Prefix string
Key string
Recursive bool
}
func (g *getAction) HTTPRequest(ep url.URL) *http.Request {
u := v2KeysURL(ep, g.Prefix, g.Key)
params := u.Query()
params.Set("recursive", strconv.FormatBool(g.Recursive))
u.RawQuery = params.Encode()
req, _ := http.NewRequest("GET", u.String(), nil)
return req
}
type waitAction struct {
Prefix string
Key string
WaitIndex uint64
Recursive bool
}
func (w *waitAction) HTTPRequest(ep url.URL) *http.Request {
u := v2KeysURL(ep, w.Prefix, w.Key)
params := u.Query()
params.Set("wait", "true")
params.Set("waitIndex", strconv.FormatUint(w.WaitIndex, 10))
params.Set("recursive", strconv.FormatBool(w.Recursive))
u.RawQuery = params.Encode()
req, _ := http.NewRequest("GET", u.String(), nil)
return req
}
type createAction struct {
Prefix string
Key string
Value string
TTL *uint64
}
func (c *createAction) HTTPRequest(ep url.URL) *http.Request {
u := v2KeysURL(ep, c.Prefix, c.Key)
params := u.Query()
params.Set("prevExist", "false")
u.RawQuery = params.Encode()
form := url.Values{}
form.Add("value", c.Value)
if c.TTL != nil {
form.Add("ttl", strconv.FormatUint(*c.TTL, 10))
}
body := strings.NewReader(form.Encode())
req, _ := http.NewRequest("PUT", u.String(), body)
req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
return req
}
func unmarshalHTTPResponse(code int, header http.Header, body []byte) (res *Response, err error) {
switch code {
case http.StatusOK, http.StatusCreated:
res, err = unmarshalSuccessfulResponse(header, body)
default:
err = unmarshalErrorResponse(code)
}
return
}
func unmarshalSuccessfulResponse(header http.Header, body []byte) (*Response, error) {
var res Response
err := json.Unmarshal(body, &res)
if err != nil {
return nil, err
}
if header.Get("X-Etcd-Index") != "" {
res.Index, err = strconv.ParseUint(header.Get("X-Etcd-Index"), 10, 64)
}
if err != nil {
return nil, err
}
return &res, nil
}
func unmarshalErrorResponse(code int) error {
switch code {
case http.StatusNotFound:
return ErrKeyNoExist
case http.StatusPreconditionFailed:
return ErrKeyExists
case http.StatusInternalServerError:
// this isn't necessarily true
return ErrNoLeader
case http.StatusGatewayTimeout:
return ErrTimeout
default:
}
return fmt.Errorf("unrecognized HTTP status code %d", code)
}