/
instrument_server_test.go
545 lines (509 loc) · 15.2 KB
/
instrument_server_test.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
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
// Copyright 2017 The Prometheus 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 promhttp
import (
"io"
"log"
"net/http"
"net/http/httptest"
"testing"
"github.com/prometheus/client_golang/prometheus"
)
func TestLabelCheck(t *testing.T) {
scenarios := map[string]struct {
metricName string // Defaults to "c".
varLabels []string
constLabels []string
curriedLabels []string
ok bool
}{
"empty": {
varLabels: []string{},
constLabels: []string{},
curriedLabels: []string{},
ok: true,
},
"code as single var label": {
varLabels: []string{"code"},
constLabels: []string{},
curriedLabels: []string{},
ok: true,
},
"method as single var label": {
varLabels: []string{"method"},
constLabels: []string{},
curriedLabels: []string{},
ok: true,
},
"code and method as var labels": {
varLabels: []string{"method", "code"},
constLabels: []string{},
curriedLabels: []string{},
ok: true,
},
"valid case with all labels used": {
varLabels: []string{"code", "method"},
constLabels: []string{"foo", "bar"},
curriedLabels: []string{"dings", "bums"},
ok: true,
},
"all labels used with an invalid const label name": {
varLabels: []string{"code", "method"},
constLabels: []string{"in-valid", "bar"},
curriedLabels: []string{"dings", "bums"},
ok: false,
},
"unsupported var label": {
varLabels: []string{"foo"},
constLabels: []string{},
curriedLabels: []string{},
ok: false,
},
"mixed var labels": {
varLabels: []string{"method", "foo", "code"},
constLabels: []string{},
curriedLabels: []string{},
ok: false,
},
"unsupported var label but curried": {
varLabels: []string{},
constLabels: []string{},
curriedLabels: []string{"foo"},
ok: true,
},
"mixed var labels but unsupported curried": {
varLabels: []string{"code", "method"},
constLabels: []string{},
curriedLabels: []string{"foo"},
ok: true,
},
"supported label as const and curry": {
varLabels: []string{},
constLabels: []string{"code"},
curriedLabels: []string{"method"},
ok: true,
},
"supported label as const and curry with unsupported as var": {
varLabels: []string{"foo"},
constLabels: []string{"code"},
curriedLabels: []string{"method"},
ok: false,
},
"invalid name and otherwise empty": {
metricName: "in-valid",
varLabels: []string{},
constLabels: []string{},
curriedLabels: []string{},
ok: false,
},
"invalid name with all the otherwise valid labels": {
metricName: "in-valid",
varLabels: []string{"code", "method"},
constLabels: []string{"foo", "bar"},
curriedLabels: []string{"dings", "bums"},
ok: false,
},
}
for name, sc := range scenarios {
t.Run(name, func(t *testing.T) {
metricName := sc.metricName
if metricName == "" {
metricName = "c"
}
constLabels := prometheus.Labels{}
for _, l := range sc.constLabels {
constLabels[l] = "dummy"
}
c := prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: metricName,
Help: "c help",
ConstLabels: constLabels,
},
append(sc.varLabels, sc.curriedLabels...),
)
o := prometheus.ObserverVec(prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: metricName,
Help: "c help",
ConstLabels: constLabels,
},
append(sc.varLabels, sc.curriedLabels...),
))
//nolint:typecheck // Ignore declared but unused error.
for _, l := range sc.curriedLabels {
c = c.MustCurryWith(prometheus.Labels{l: "dummy"})
o = o.MustCurryWith(prometheus.Labels{l: "dummy"})
}
func() {
defer func() {
if err := recover(); err != nil {
if sc.ok {
t.Error("unexpected panic:", err)
}
} else if !sc.ok {
t.Error("expected panic")
}
}()
InstrumentHandlerCounter(c, nil)
}()
func() {
defer func() {
if err := recover(); err != nil {
if sc.ok {
t.Error("unexpected panic:", err)
}
} else if !sc.ok {
t.Error("expected panic")
}
}()
InstrumentHandlerDuration(o, nil)
}()
if sc.ok {
// Test if wantCode and wantMethod were detected correctly.
var wantCode, wantMethod bool
for _, l := range sc.varLabels {
if l == "code" {
wantCode = true
}
if l == "method" {
wantMethod = true
}
}
gotCode, gotMethod := checkLabels(c)
if gotCode != wantCode {
t.Errorf("wanted code=%t for counter, got code=%t", wantCode, gotCode)
}
if gotMethod != wantMethod {
t.Errorf("wanted method=%t for counter, got method=%t", wantMethod, gotMethod)
}
gotCode, gotMethod = checkLabels(o)
if gotCode != wantCode {
t.Errorf("wanted code=%t for observer, got code=%t", wantCode, gotCode)
}
if gotMethod != wantMethod {
t.Errorf("wanted method=%t for observer, got method=%t", wantMethod, gotMethod)
}
}
})
}
}
func TestLabels(t *testing.T) {
scenarios := map[string]struct {
varLabels []string
reqMethod string
respStatus int
extraMethods []string
wantLabels prometheus.Labels
ok bool
}{
"empty": {
varLabels: []string{},
wantLabels: emptyLabels,
reqMethod: "GET",
respStatus: 200,
ok: true,
},
"code as single var label": {
varLabels: []string{"code"},
reqMethod: "GET",
respStatus: 200,
wantLabels: prometheus.Labels{"code": "200"},
ok: true,
},
"code as single var label and out-of-range code": {
varLabels: []string{"code"},
reqMethod: "GET",
respStatus: 99,
wantLabels: prometheus.Labels{"code": "unknown"},
ok: true,
},
"code as single var label and in-range but unrecognized code": {
varLabels: []string{"code"},
reqMethod: "GET",
respStatus: 308,
wantLabels: prometheus.Labels{"code": "308"},
ok: true,
},
"method as single var label": {
varLabels: []string{"method"},
reqMethod: "GET",
respStatus: 200,
wantLabels: prometheus.Labels{"method": "get"},
ok: true,
},
"method as single var label and unknown method": {
varLabels: []string{"method"},
reqMethod: "CUSTOM_METHOD",
respStatus: 200,
wantLabels: prometheus.Labels{"method": "unknown"},
ok: true,
},
"code and method as var labels": {
varLabels: []string{"method", "code"},
reqMethod: "GET",
respStatus: 200,
wantLabels: prometheus.Labels{"method": "get", "code": "200"},
ok: true,
},
"method as single var label with extra methods specified": {
varLabels: []string{"method"},
reqMethod: "CUSTOM_METHOD",
respStatus: 200,
extraMethods: []string{"CUSTOM_METHOD", "CUSTOM_METHOD_1"},
wantLabels: prometheus.Labels{"method": "custom_method"},
ok: true,
},
"all labels used with an unknown method and out-of-range code": {
varLabels: []string{"code", "method"},
reqMethod: "CUSTOM_METHOD",
respStatus: 99,
wantLabels: prometheus.Labels{"method": "unknown", "code": "unknown"},
ok: false,
},
}
checkLabels := func(labels []string) (gotCode bool, gotMethod bool) {
for _, label := range labels {
switch label {
case "code":
gotCode = true
case "method":
gotMethod = true
default:
panic("metric partitioned with non-supported labels for this test")
}
}
return
}
equalLabels := func(gotLabels, wantLabels prometheus.Labels) bool {
if len(gotLabels) != len(wantLabels) {
return false
}
for ln, lv := range gotLabels {
olv, ok := wantLabels[ln]
if !ok {
return false
}
if olv != lv {
return false
}
}
return true
}
for name, sc := range scenarios {
t.Run(name, func(t *testing.T) {
if sc.ok {
gotCode, gotMethod := checkLabels(sc.varLabels)
gotLabels := labels(gotCode, gotMethod, sc.reqMethod, sc.respStatus, sc.extraMethods...)
if !equalLabels(gotLabels, sc.wantLabels) {
t.Errorf("wanted labels=%v for counter, got code=%v", sc.wantLabels, gotLabels)
}
}
})
}
}
func TestMiddlewareAPI(t *testing.T) {
reg := prometheus.NewRegistry()
inFlightGauge := prometheus.NewGauge(prometheus.GaugeOpts{
Name: "in_flight_requests",
Help: "A gauge of requests currently being served by the wrapped handler.",
})
counter := prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "api_requests_total",
Help: "A counter for requests to the wrapped handler.",
},
[]string{"code", "method"},
)
histVec := prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: "response_duration_seconds",
Help: "A histogram of request latencies.",
Buckets: prometheus.DefBuckets,
ConstLabels: prometheus.Labels{"handler": "api"},
},
[]string{"method"},
)
writeHeaderVec := prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: "write_header_duration_seconds",
Help: "A histogram of time to first write latencies.",
Buckets: prometheus.DefBuckets,
ConstLabels: prometheus.Labels{"handler": "api"},
},
[]string{},
)
responseSize := prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: "push_request_size_bytes",
Help: "A histogram of request sizes for requests.",
Buckets: []float64{200, 500, 900, 1500},
},
[]string{},
)
handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("OK"))
})
reg.MustRegister(inFlightGauge, counter, histVec, responseSize, writeHeaderVec)
chain := InstrumentHandlerInFlight(inFlightGauge,
InstrumentHandlerCounter(counter,
InstrumentHandlerDuration(histVec,
InstrumentHandlerTimeToWriteHeader(writeHeaderVec,
InstrumentHandlerResponseSize(responseSize, handler),
),
),
),
)
r, _ := http.NewRequest("GET", "www.example.com", nil)
w := httptest.NewRecorder()
chain.ServeHTTP(w, r)
}
func TestInstrumentTimeToFirstWrite(t *testing.T) {
var i int
dobs := &responseWriterDelegator{
ResponseWriter: httptest.NewRecorder(),
observeWriteHeader: func(status int) {
i = status
},
}
d := newDelegator(dobs, nil)
d.WriteHeader(http.StatusOK)
if i != http.StatusOK {
t.Fatalf("failed to execute observeWriteHeader")
}
}
// testResponseWriter is an http.ResponseWriter that also implements
// http.CloseNotifier, http.Flusher, and io.ReaderFrom.
type testResponseWriter struct {
closeNotifyCalled, flushCalled, readFromCalled bool
}
func (t *testResponseWriter) Header() http.Header { return nil }
func (t *testResponseWriter) Write([]byte) (int, error) { return 0, nil }
func (t *testResponseWriter) WriteHeader(int) {}
func (t *testResponseWriter) CloseNotify() <-chan bool {
t.closeNotifyCalled = true
return nil
}
func (t *testResponseWriter) Flush() { t.flushCalled = true }
func (t *testResponseWriter) ReadFrom(io.Reader) (int64, error) {
t.readFromCalled = true
return 0, nil
}
// testFlusher is an http.ResponseWriter that also implements http.Flusher.
type testFlusher struct {
flushCalled bool
}
func (t *testFlusher) Header() http.Header { return nil }
func (t *testFlusher) Write([]byte) (int, error) { return 0, nil }
func (t *testFlusher) WriteHeader(int) {}
func (t *testFlusher) Flush() { t.flushCalled = true }
func TestInterfaceUpgrade(t *testing.T) {
w := &testResponseWriter{}
d := newDelegator(w, nil)
//nolint:staticcheck // Ignore SA1019. http.CloseNotifier is deprecated but we keep it here to not break existing users.
d.(http.CloseNotifier).CloseNotify()
if !w.closeNotifyCalled {
t.Error("CloseNotify not called")
}
d.(http.Flusher).Flush()
if !w.flushCalled {
t.Error("Flush not called")
}
d.(io.ReaderFrom).ReadFrom(nil)
if !w.readFromCalled {
t.Error("ReadFrom not called")
}
if _, ok := d.(http.Hijacker); ok {
t.Error("delegator unexpectedly implements http.Hijacker")
}
f := &testFlusher{}
d = newDelegator(f, nil)
//nolint:staticcheck // Ignore SA1019. http.CloseNotifier is deprecated but we keep it here to not break existing users.
if _, ok := d.(http.CloseNotifier); ok {
t.Error("delegator unexpectedly implements http.CloseNotifier")
}
d.(http.Flusher).Flush()
if !w.flushCalled {
t.Error("Flush not called")
}
if _, ok := d.(io.ReaderFrom); ok {
t.Error("delegator unexpectedly implements io.ReaderFrom")
}
if _, ok := d.(http.Hijacker); ok {
t.Error("delegator unexpectedly implements http.Hijacker")
}
}
func ExampleInstrumentHandlerDuration() {
inFlightGauge := prometheus.NewGauge(prometheus.GaugeOpts{
Name: "in_flight_requests",
Help: "A gauge of requests currently being served by the wrapped handler.",
})
counter := prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "api_requests_total",
Help: "A counter for requests to the wrapped handler.",
},
[]string{"code", "method"},
)
// duration is partitioned by the HTTP method and handler. It uses custom
// buckets based on the expected request duration.
duration := prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: "request_duration_seconds",
Help: "A histogram of latencies for requests.",
Buckets: []float64{.25, .5, 1, 2.5, 5, 10},
},
[]string{"handler", "method"},
)
// responseSize has no labels, making it a zero-dimensional
// ObserverVec.
responseSize := prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: "response_size_bytes",
Help: "A histogram of response sizes for requests.",
Buckets: []float64{200, 500, 900, 1500},
},
[]string{},
)
// Create the handlers that will be wrapped by the middleware.
pushHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("Push"))
})
pullHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("Pull"))
})
// Register all of the metrics in the standard registry.
prometheus.MustRegister(inFlightGauge, counter, duration, responseSize)
// Instrument the handlers with all the metrics, injecting the "handler"
// label by currying.
pushChain := InstrumentHandlerInFlight(inFlightGauge,
InstrumentHandlerDuration(duration.MustCurryWith(prometheus.Labels{"handler": "push"}),
InstrumentHandlerCounter(counter,
InstrumentHandlerResponseSize(responseSize, pushHandler),
),
),
)
pullChain := InstrumentHandlerInFlight(inFlightGauge,
InstrumentHandlerDuration(duration.MustCurryWith(prometheus.Labels{"handler": "pull"}),
InstrumentHandlerCounter(counter,
InstrumentHandlerResponseSize(responseSize, pullHandler),
),
),
)
http.Handle("/metrics", Handler())
http.Handle("/push", pushChain)
http.Handle("/pull", pullChain)
if err := http.ListenAndServe(":3000", nil); err != nil {
log.Fatal(err)
}
}