forked from juju/juju
/
transports.go
272 lines (243 loc) · 7.27 KB
/
transports.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
// Copyright 2021 Canonical Ltd.
// Licensed under the AGPLv3, see LICENCE file for details.
package internal
import (
"encoding/json"
"fmt"
"io/ioutil"
"net/http"
"net/url"
"strings"
"time"
"github.com/docker/distribution/registry/client/auth/challenge"
"github.com/juju/errors"
)
type basicTransport struct {
transport http.RoundTripper
username string
password string
authToken string
}
func newBasicTransport(
transport http.RoundTripper, username string, password string, authToken string,
) http.RoundTripper {
return &basicTransport{
transport: transport,
username: username,
password: password,
authToken: authToken,
}
}
func (basicTransport) scheme() string {
return "Basic"
}
func (t basicTransport) authorizeRequest(req *http.Request) error {
if t.authToken != "" {
req.Header.Set("Authorization", fmt.Sprintf("%s %s", t.scheme(), t.authToken))
return nil
}
if t.username != "" || t.password != "" {
req.SetBasicAuth(t.username, t.password)
}
return nil
}
// RoundTrip executes a single HTTP transaction, returning a Response for the provided Request.
func (t basicTransport) RoundTrip(req *http.Request) (*http.Response, error) {
if err := t.authorizeRequest(req); err != nil {
return nil, errors.Trace(err)
}
resp, err := t.transport.RoundTrip(req)
logger.Tracef("basicTransport %q, resp.Header => %#v, %q", req.URL, resp.Header, resp.Status)
return resp, errors.Trace(err)
}
type tokenTransport struct {
transport http.RoundTripper
username string
password string
authToken string
OAuthToken string
reuseOAuthToken bool
}
func newTokenTransport(
transport http.RoundTripper, username, password, authToken, OAuthToken string, reuseOAuthToken bool,
) http.RoundTripper {
return &tokenTransport{
transport: transport,
username: username,
password: password,
authToken: authToken,
OAuthToken: OAuthToken,
reuseOAuthToken: reuseOAuthToken,
}
}
func (tokenTransport) scheme() string {
return "Bearer"
}
func getChallengeParameters(scheme string, resp *http.Response) map[string]string {
logger.Tracef(
"getting chanllenge parametter for %q with scheme %q from %q",
resp.Request.URL.String(),
scheme, resp.Header[http.CanonicalHeaderKey("WWW-Authenticate")],
)
for _, c := range challenge.ResponseChallenges(resp) {
if strings.EqualFold(c.Scheme, scheme) {
return c.Parameters
}
}
logger.Tracef("failed to get challenge parameters for %q schema -> %v", scheme, resp.Header)
return nil
}
type tokenResponse struct {
Token string `json:"token"`
AccessToken string `json:"access_token"`
RefreshToken string `json:"refresh_token"`
ExpiresIn int `json:"expires_in"`
IssuedAt time.Time `json:"issued_at"`
Scope string `json:"scope"`
}
func (t tokenResponse) token() string {
if t.AccessToken != "" {
return t.AccessToken
}
if t.Token != "" {
return t.Token
}
return ""
}
func (t *tokenTransport) refreshOAuthToken(failedResp *http.Response) error {
t.OAuthToken = ""
parameters := getChallengeParameters(t.scheme(), failedResp)
if len(parameters) == 0 {
return errors.NewForbidden(nil, "failed to refresh bearer token")
}
realm, ok := parameters["realm"]
if !ok {
return errors.New("no realm specified for token auth challenge")
}
service, ok := parameters["service"]
if !ok {
return errors.New("no service specified for token auth challenge")
}
scope, ok := parameters["scope"]
if !ok {
logger.Tracef("no scope specified for token auth challenge")
}
url, err := url.Parse(realm)
if err != nil {
return errors.Trace(err)
}
q := url.Query()
if scope != "" {
q.Set("scope", scope)
}
q.Set("service", service)
url.RawQuery = q.Encode()
request, err := http.NewRequest("GET", url.String(), nil)
if err != nil {
return errors.Trace(err)
}
tokenRefreshTransport := newBasicTransport(t.transport, t.username, t.password, t.authToken)
resp, err := tokenRefreshTransport.RoundTrip(request)
if err != nil {
return errors.Trace(err)
}
if resp.StatusCode != http.StatusOK {
_, err = handleErrorResponse(resp)
return errors.Trace(err)
}
decoder := json.NewDecoder(resp.Body)
var tr tokenResponse
if err = decoder.Decode(&tr); err != nil {
return fmt.Errorf("unable to decode token response: %s", err)
}
t.OAuthToken = tr.token()
return nil
}
func (t *tokenTransport) authorizeRequest(req *http.Request) error {
if t.OAuthToken != "" {
req.Header.Set("Authorization", fmt.Sprintf("%s %s", t.scheme(), t.OAuthToken))
}
return nil
}
// RoundTrip executes a single HTTP transaction, returning a Response for the provided Request.
func (t *tokenTransport) RoundTrip(req *http.Request) (*http.Response, error) {
defer func() {
if !t.reuseOAuthToken {
// We usually do not re-use the OAuth token because each API call might have different scope.
// But some of the provider use long life token and there is no need to refresh.
t.OAuthToken = ""
}
}()
if err := t.authorizeRequest(req); err != nil {
return nil, errors.Trace(err)
}
resp, err := t.transport.RoundTrip(req)
if err != nil {
return nil, errors.Trace(err)
}
if isUnauthorizedResponse(resp) {
// refresh token and retry.
return t.retry(req, resp)
}
return resp, errors.Trace(err)
}
func (t *tokenTransport) retry(req *http.Request, prevResp *http.Response) (*http.Response, error) {
logger.Tracef(
"retrying req URL %q, previous response header %#v, status %v",
req.URL, prevResp.Header, prevResp.Status,
)
if err := t.refreshOAuthToken(prevResp); err != nil {
return nil, errors.Annotatef(err, "refreshing OAuth token")
}
if err := t.authorizeRequest(req); err != nil {
return nil, errors.Trace(err)
}
resp, err := t.transport.RoundTrip(req)
if isUnauthorizedResponse(resp) {
if t.password == "" && t.authToken == "" {
return nil, errors.NewUnauthorized(err, "authorization is required for a private registry")
}
}
return resp, errors.Trace(err)
}
func isUnauthorizedResponse(resp *http.Response) bool {
return resp != nil && resp.StatusCode == http.StatusUnauthorized
}
type errorTransport struct {
transport http.RoundTripper
}
func newErrorTransport(transport http.RoundTripper) http.RoundTripper {
return &errorTransport{transport: transport}
}
// RoundTrip executes a single HTTP transaction, returning a Response for the provided Request.
func (t errorTransport) RoundTrip(request *http.Request) (*http.Response, error) {
resp, err := t.transport.RoundTrip(request)
if err != nil {
return resp, errors.Trace(err)
}
if resp.StatusCode < 400 {
return resp, nil
}
logger.Tracef("errorTransport %q, err -> %v", request.URL, err)
return handleErrorResponse(resp)
}
func handleErrorResponse(resp *http.Response) (*http.Response, error) {
if resp.StatusCode < 400 {
return resp, nil
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
return nil, errors.Annotatef(err, "reading bad response body with status code %d", resp.StatusCode)
}
errMsg := fmt.Sprintf("non-successful response status=%d", resp.StatusCode)
logger.Tracef("%s, url %q, body=%q", errMsg, resp.Request.URL.String(), body)
errNew := errors.Errorf
switch resp.StatusCode {
case http.StatusForbidden:
errNew = errors.Forbiddenf
case http.StatusUnauthorized:
errNew = errors.Unauthorizedf
}
return nil, errNew(errMsg)
}