-
Notifications
You must be signed in to change notification settings - Fork 1
/
httpstream.go
309 lines (269 loc) · 10.6 KB
/
httpstream.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
/*
Copyright 2016 The Kubernetes Authors.
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 portforward
import (
"errors"
"fmt"
"net/http"
"strconv"
"sync"
"time"
"k8s.io/apimachinery/pkg/types"
"k8s.io/apimachinery/pkg/util/httpstream"
"k8s.io/apimachinery/pkg/util/httpstream/spdy"
utilruntime "k8s.io/apimachinery/pkg/util/runtime"
api "k8s.io/kubernetes/pkg/apis/core"
"k8s.io/klog"
)
func handleHTTPStreams(req *http.Request, w http.ResponseWriter, portForwarder PortForwarder, podName string, uid types.UID, supportedPortForwardProtocols []string, idleTimeout, streamCreationTimeout time.Duration) error {
_, err := httpstream.Handshake(req, w, supportedPortForwardProtocols)
// negotiated protocol isn't currently used server side, but could be in the future
if err != nil {
// Handshake writes the error to the client
return err
}
streamChan := make(chan httpstream.Stream, 1)
klog.V(5).Infof("Upgrading port forward response")
upgrader := spdy.NewResponseUpgrader()
conn := upgrader.UpgradeResponse(w, req, httpStreamReceived(streamChan))
if conn == nil {
return errors.New("Unable to upgrade httpstream connection")
}
defer conn.Close()
klog.V(5).Infof("(conn=%p) setting port forwarding streaming connection idle timeout to %v", conn, idleTimeout)
conn.SetIdleTimeout(idleTimeout)
h := &httpStreamHandler{
conn: conn,
streamChan: streamChan,
streamPairs: make(map[string]*httpStreamPair),
streamCreationTimeout: streamCreationTimeout,
pod: podName,
uid: uid,
forwarder: portForwarder,
}
h.run()
return nil
}
// httpStreamReceived is the httpstream.NewStreamHandler for port
// forward streams. It checks each stream's port and stream type headers,
// rejecting any streams that with missing or invalid values. Each valid
// stream is sent to the streams channel.
func httpStreamReceived(streams chan httpstream.Stream) func(httpstream.Stream, <-chan struct{}) error {
return func(stream httpstream.Stream, replySent <-chan struct{}) error {
// make sure it has a valid port header
portString := stream.Headers().Get(api.PortHeader)
if len(portString) == 0 {
return fmt.Errorf("%q header is required", api.PortHeader)
}
port, err := strconv.ParseUint(portString, 10, 16)
if err != nil {
return fmt.Errorf("unable to parse %q as a port: %v", portString, err)
}
if port < 1 {
return fmt.Errorf("port %q must be > 0", portString)
}
// make sure it has a valid stream type header
streamType := stream.Headers().Get(api.StreamType)
if len(streamType) == 0 {
return fmt.Errorf("%q header is required", api.StreamType)
}
if streamType != api.StreamTypeError && streamType != api.StreamTypeData {
return fmt.Errorf("invalid stream type %q", streamType)
}
streams <- stream
return nil
}
}
// httpStreamHandler is capable of processing multiple port forward
// requests over a single httpstream.Connection.
type httpStreamHandler struct {
conn httpstream.Connection
streamChan chan httpstream.Stream
streamPairsLock sync.RWMutex
streamPairs map[string]*httpStreamPair
streamCreationTimeout time.Duration
pod string
uid types.UID
forwarder PortForwarder
}
// getStreamPair returns a httpStreamPair for requestID. This creates a
// new pair if one does not yet exist for the requestID. The returned bool is
// true if the pair was created.
func (h *httpStreamHandler) getStreamPair(requestID string) (*httpStreamPair, bool) {
h.streamPairsLock.Lock()
defer h.streamPairsLock.Unlock()
if p, ok := h.streamPairs[requestID]; ok {
klog.V(5).Infof("(conn=%p, request=%s) found existing stream pair", h.conn, requestID)
return p, false
}
klog.V(5).Infof("(conn=%p, request=%s) creating new stream pair", h.conn, requestID)
p := newPortForwardPair(requestID)
h.streamPairs[requestID] = p
return p, true
}
// monitorStreamPair waits for the pair to receive both its error and data
// streams, or for the timeout to expire (whichever happens first), and then
// removes the pair.
func (h *httpStreamHandler) monitorStreamPair(p *httpStreamPair, timeout <-chan time.Time) {
select {
case <-timeout:
err := fmt.Errorf("(conn=%v, request=%s) timed out waiting for streams", h.conn, p.requestID)
utilruntime.HandleError(err)
p.printError(err.Error())
case <-p.complete:
klog.V(5).Infof("(conn=%v, request=%s) successfully received error and data streams", h.conn, p.requestID)
}
h.removeStreamPair(p.requestID)
}
// hasStreamPair returns a bool indicating if a stream pair for requestID
// exists.
func (h *httpStreamHandler) hasStreamPair(requestID string) bool {
h.streamPairsLock.RLock()
defer h.streamPairsLock.RUnlock()
_, ok := h.streamPairs[requestID]
return ok
}
// removeStreamPair removes the stream pair identified by requestID from streamPairs.
func (h *httpStreamHandler) removeStreamPair(requestID string) {
h.streamPairsLock.Lock()
defer h.streamPairsLock.Unlock()
delete(h.streamPairs, requestID)
}
// requestID returns the request id for stream.
func (h *httpStreamHandler) requestID(stream httpstream.Stream) string {
requestID := stream.Headers().Get(api.PortForwardRequestIDHeader)
if len(requestID) == 0 {
klog.V(5).Infof("(conn=%p) stream received without %s header", h.conn, api.PortForwardRequestIDHeader)
// If we get here, it's because the connection came from an older client
// that isn't generating the request id header
// (https://github.com/kubernetes/kubernetes/blob/843134885e7e0b360eb5441e85b1410a8b1a7a0c/pkg/client/unversioned/portforward/portforward.go#L258-L287)
//
// This is a best-effort attempt at supporting older clients.
//
// When there aren't concurrent new forwarded connections, each connection
// will have a pair of streams (data, error), and the stream IDs will be
// consecutive odd numbers, e.g. 1 and 3 for the first connection. Convert
// the stream ID into a pseudo-request id by taking the stream type and
// using id = stream.Identifier() when the stream type is error,
// and id = stream.Identifier() - 2 when it's data.
//
// NOTE: this only works when there are not concurrent new streams from
// multiple forwarded connections; it's a best-effort attempt at supporting
// old clients that don't generate request ids. If there are concurrent
// new connections, it's possible that 1 connection gets streams whose IDs
// are not consecutive (e.g. 5 and 9 instead of 5 and 7).
streamType := stream.Headers().Get(api.StreamType)
switch streamType {
case api.StreamTypeError:
requestID = strconv.Itoa(int(stream.Identifier()))
case api.StreamTypeData:
requestID = strconv.Itoa(int(stream.Identifier()) - 2)
}
klog.V(5).Infof("(conn=%p) automatically assigning request ID=%q from stream type=%s, stream ID=%d", h.conn, requestID, streamType, stream.Identifier())
}
return requestID
}
// run is the main loop for the httpStreamHandler. It processes new
// streams, invoking portForward for each complete stream pair. The loop exits
// when the httpstream.Connection is closed.
func (h *httpStreamHandler) run() {
klog.V(5).Infof("(conn=%p) waiting for port forward streams", h.conn)
Loop:
for {
select {
case <-h.conn.CloseChan():
klog.V(5).Infof("(conn=%p) upgraded connection closed", h.conn)
break Loop
case stream := <-h.streamChan:
requestID := h.requestID(stream)
streamType := stream.Headers().Get(api.StreamType)
klog.V(5).Infof("(conn=%p, request=%s) received new stream of type %s", h.conn, requestID, streamType)
p, created := h.getStreamPair(requestID)
if created {
go h.monitorStreamPair(p, time.After(h.streamCreationTimeout))
}
if complete, err := p.add(stream); err != nil {
msg := fmt.Sprintf("error processing stream for request %s: %v", requestID, err)
utilruntime.HandleError(errors.New(msg))
p.printError(msg)
} else if complete {
go h.portForward(p)
}
}
}
}
// portForward invokes the httpStreamHandler's forwarder.PortForward
// function for the given stream pair.
func (h *httpStreamHandler) portForward(p *httpStreamPair) {
defer p.dataStream.Close()
defer p.errorStream.Close()
portString := p.dataStream.Headers().Get(api.PortHeader)
port, _ := strconv.ParseInt(portString, 10, 32)
klog.V(5).Infof("(conn=%p, request=%s) invoking forwarder.PortForward for port %s", h.conn, p.requestID, portString)
err := h.forwarder.PortForward(h.pod, h.uid, int32(port), p.dataStream)
klog.V(5).Infof("(conn=%p, request=%s) done invoking forwarder.PortForward for port %s", h.conn, p.requestID, portString)
if err != nil {
msg := fmt.Errorf("error forwarding port %d to pod %s, uid %v: %v", port, h.pod, h.uid, err)
utilruntime.HandleError(msg)
fmt.Fprint(p.errorStream, msg.Error())
}
}
// httpStreamPair represents the error and data streams for a port
// forwarding request.
type httpStreamPair struct {
lock sync.RWMutex
requestID string
dataStream httpstream.Stream
errorStream httpstream.Stream
complete chan struct{}
}
// newPortForwardPair creates a new httpStreamPair.
func newPortForwardPair(requestID string) *httpStreamPair {
return &httpStreamPair{
requestID: requestID,
complete: make(chan struct{}),
}
}
// add adds the stream to the httpStreamPair. If the pair already
// contains a stream for the new stream's type, an error is returned. add
// returns true if both the data and error streams for this pair have been
// received.
func (p *httpStreamPair) add(stream httpstream.Stream) (bool, error) {
p.lock.Lock()
defer p.lock.Unlock()
switch stream.Headers().Get(api.StreamType) {
case api.StreamTypeError:
if p.errorStream != nil {
return false, errors.New("error stream already assigned")
}
p.errorStream = stream
case api.StreamTypeData:
if p.dataStream != nil {
return false, errors.New("data stream already assigned")
}
p.dataStream = stream
}
complete := p.errorStream != nil && p.dataStream != nil
if complete {
close(p.complete)
}
return complete, nil
}
// printError writes s to p.errorStream if p.errorStream has been set.
func (p *httpStreamPair) printError(s string) {
p.lock.RLock()
defer p.lock.RUnlock()
if p.errorStream != nil {
fmt.Fprint(p.errorStream, s)
}
}