1
|
|
|
package otelroundtripper |
2
|
|
|
|
3
|
|
|
import ( |
4
|
|
|
"context" |
5
|
|
|
"errors" |
6
|
|
|
"net" |
7
|
|
|
"net/http" |
8
|
|
|
"strings" |
9
|
|
|
"time" |
10
|
|
|
|
11
|
|
|
"go.opentelemetry.io/otel/attribute" |
12
|
|
|
"go.opentelemetry.io/otel/metric/instrument/syncint64" |
13
|
|
|
semconv "go.opentelemetry.io/otel/semconv/v1.7.0" |
14
|
|
|
) |
15
|
|
|
|
16
|
|
|
type otelHTTPMetrics struct { |
17
|
|
|
attemptsCounter syncint64.Counter |
18
|
|
|
noRequestCounter syncint64.Counter |
19
|
|
|
errorsCounter syncint64.Counter |
20
|
|
|
successesCounter syncint64.Counter |
21
|
|
|
failureCounter syncint64.Counter |
22
|
|
|
redirectCounter syncint64.Counter |
23
|
|
|
timeoutsCounter syncint64.Counter |
24
|
|
|
canceledCounter syncint64.Counter |
25
|
|
|
deadlineExceededCounter syncint64.Counter |
26
|
|
|
totalDurationCounter syncint64.Histogram |
27
|
|
|
inFlightCounter syncint64.UpDownCounter |
28
|
|
|
} |
29
|
|
|
|
30
|
|
|
// otelRoundTripper is the http.RoundTripper which emits open telemetry metrics |
31
|
|
|
type otelRoundTripper struct { |
32
|
|
|
parent http.RoundTripper |
33
|
|
|
attributes []attribute.KeyValue |
34
|
|
|
metrics otelHTTPMetrics |
35
|
|
|
} |
36
|
|
|
|
37
|
|
|
// New creates a new instance of the http.RoundTripper |
38
|
|
|
func New(options ...Option) http.RoundTripper { |
39
|
|
|
cfg := defaultConfig() |
40
|
|
|
|
41
|
|
|
for _, option := range options { |
42
|
|
|
option.apply(cfg) |
43
|
|
|
} |
44
|
|
|
|
45
|
|
|
return &otelRoundTripper{ |
46
|
|
|
parent: cfg.parent, |
47
|
|
|
attributes: cfg.attributes, |
48
|
|
|
metrics: otelHTTPMetrics{ |
49
|
|
|
noRequestCounter: mustCounter(cfg.meter.SyncInt64().Counter(cfg.name + ".no_request")), |
50
|
|
|
errorsCounter: mustCounter(cfg.meter.SyncInt64().Counter(cfg.name + ".errors")), |
51
|
|
|
successesCounter: mustCounter(cfg.meter.SyncInt64().Counter(cfg.name + ".success")), |
52
|
|
|
timeoutsCounter: mustCounter(cfg.meter.SyncInt64().Counter(cfg.name + ".timeouts")), |
53
|
|
|
canceledCounter: mustCounter(cfg.meter.SyncInt64().Counter(cfg.name + ".cancelled")), |
54
|
|
|
deadlineExceededCounter: mustCounter(cfg.meter.SyncInt64().Counter(cfg.name + ".deadline_exceeded")), |
55
|
|
|
totalDurationCounter: mustHistogram(cfg.meter.SyncInt64().Histogram(cfg.name + ".total_duration")), |
56
|
|
|
inFlightCounter: mustUpDownCounter(cfg.meter.SyncInt64().UpDownCounter(cfg.name + ".in_flight")), |
57
|
|
|
attemptsCounter: mustCounter(cfg.meter.SyncInt64().Counter(cfg.name + ".attempts")), |
58
|
|
|
failureCounter: mustCounter(cfg.meter.SyncInt64().Counter(cfg.name + ".failures")), |
59
|
|
|
redirectCounter: mustCounter(cfg.meter.SyncInt64().Counter(cfg.name + ".redirects")), |
60
|
|
|
}, |
61
|
|
|
} |
62
|
|
|
} |
63
|
|
|
|
64
|
|
|
func mustCounter(counter syncint64.Counter, err error) syncint64.Counter { |
65
|
|
|
if err != nil { |
66
|
|
|
panic(err) |
67
|
|
|
} |
68
|
|
|
return counter |
69
|
|
|
} |
70
|
|
|
|
71
|
|
|
func mustUpDownCounter(counter syncint64.UpDownCounter, err error) syncint64.UpDownCounter { |
72
|
|
|
if err != nil { |
73
|
|
|
panic(err) |
74
|
|
|
} |
75
|
|
|
return counter |
76
|
|
|
} |
77
|
|
|
|
78
|
|
|
func mustHistogram(histogram syncint64.Histogram, err error) syncint64.Histogram { |
79
|
|
|
if err != nil { |
80
|
|
|
panic(err) |
81
|
|
|
} |
82
|
|
|
return histogram |
83
|
|
|
} |
84
|
|
|
|
85
|
|
|
// RoundTrip executes a single HTTP transaction, returning a Response for the provided Request. |
86
|
|
|
func (roundTripper *otelRoundTripper) RoundTrip(request *http.Request) (*http.Response, error) { |
87
|
|
|
ctx := roundTripper.extractCtx(request) |
88
|
|
|
attributes := roundTripper.requestAttributes(request) |
89
|
|
|
|
90
|
|
|
roundTripper.beforeHook(ctx, attributes, request) |
91
|
|
|
|
92
|
|
|
start := time.Now() |
93
|
|
|
response, err := roundTripper.parent.RoundTrip(request) |
94
|
|
|
duration := time.Since(start).Milliseconds() |
95
|
|
|
|
96
|
|
|
if err != nil { |
97
|
|
|
roundTripper.errorHook(ctx, err, attributes) |
98
|
|
|
return response, err |
99
|
|
|
} |
100
|
|
|
|
101
|
|
|
attributes = roundTripper.responseAttributes(attributes, response) |
102
|
|
|
roundTripper.afterHook(ctx, duration, attributes) |
103
|
|
|
|
104
|
|
|
if roundTripper.isRedirection(response) { |
105
|
|
|
roundTripper.redirectHook(ctx, attributes) |
106
|
|
|
return response, err |
107
|
|
|
} |
108
|
|
|
|
109
|
|
|
if roundTripper.isFailure(response) { |
110
|
|
|
roundTripper.failureHook(ctx, attributes) |
111
|
|
|
return response, err |
112
|
|
|
} |
113
|
|
|
|
114
|
|
|
roundTripper.successHook(ctx, attributes) |
115
|
|
|
return response, err |
116
|
|
|
} |
117
|
|
|
|
118
|
|
|
func (roundTripper *otelRoundTripper) isFailure(response *http.Response) bool { |
119
|
|
|
if response == nil { |
120
|
|
|
return false |
121
|
|
|
} |
122
|
|
|
return response.StatusCode >= http.StatusBadRequest |
123
|
|
|
} |
124
|
|
|
|
125
|
|
|
func (roundTripper *otelRoundTripper) isRedirection(response *http.Response) bool { |
126
|
|
|
if response == nil { |
127
|
|
|
return false |
128
|
|
|
} |
129
|
|
|
return response.StatusCode >= http.StatusMultipleChoices && response.StatusCode < http.StatusBadRequest |
130
|
|
|
} |
131
|
|
|
|
132
|
|
|
func (roundTripper *otelRoundTripper) failureHook( |
133
|
|
|
ctx context.Context, |
134
|
|
|
attributes []attribute.KeyValue, |
135
|
|
|
) { |
136
|
|
|
roundTripper.metrics.inFlightCounter.Add(ctx, -1, attributes...) |
137
|
|
|
roundTripper.metrics.failureCounter.Add(ctx, 1, attributes...) |
138
|
|
|
} |
139
|
|
|
|
140
|
|
|
func (roundTripper *otelRoundTripper) redirectHook( |
141
|
|
|
ctx context.Context, |
142
|
|
|
attributes []attribute.KeyValue, |
143
|
|
|
) { |
144
|
|
|
roundTripper.metrics.inFlightCounter.Add(ctx, -1, attributes...) |
145
|
|
|
roundTripper.metrics.redirectCounter.Add(ctx, 1, attributes...) |
146
|
|
|
} |
147
|
|
|
|
148
|
|
|
func (roundTripper *otelRoundTripper) successHook( |
149
|
|
|
ctx context.Context, |
150
|
|
|
attributes []attribute.KeyValue, |
151
|
|
|
) { |
152
|
|
|
roundTripper.metrics.inFlightCounter.Add(ctx, -1, attributes...) |
153
|
|
|
roundTripper.metrics.successesCounter.Add(ctx, 1, attributes...) |
154
|
|
|
} |
155
|
|
|
|
156
|
|
|
func (roundTripper *otelRoundTripper) beforeHook( |
157
|
|
|
ctx context.Context, |
158
|
|
|
attributes []attribute.KeyValue, |
159
|
|
|
request *http.Request, |
160
|
|
|
) { |
161
|
|
|
roundTripper.metrics.inFlightCounter.Add(ctx, 1, attributes...) |
162
|
|
|
roundTripper.metrics.attemptsCounter.Add(ctx, 1, attributes...) |
163
|
|
|
if request == nil { |
164
|
|
|
roundTripper.metrics.noRequestCounter.Add(ctx, 1, attributes...) |
165
|
|
|
} |
166
|
|
|
} |
167
|
|
|
|
168
|
|
|
func (roundTripper *otelRoundTripper) afterHook( |
169
|
|
|
ctx context.Context, |
170
|
|
|
duration int64, |
171
|
|
|
attributes []attribute.KeyValue, |
172
|
|
|
) { |
173
|
|
|
roundTripper.metrics.totalDurationCounter.Record(ctx, duration, attributes...) |
174
|
|
|
} |
175
|
|
|
|
176
|
|
|
func (roundTripper *otelRoundTripper) responseAttributes( |
177
|
|
|
attributes []attribute.KeyValue, |
178
|
|
|
response *http.Response, |
179
|
|
|
) []attribute.KeyValue { |
180
|
|
|
return append( |
181
|
|
|
append([]attribute.KeyValue{}, attributes...), |
182
|
|
|
roundTripper.extractResponseAttributes(response)..., |
183
|
|
|
) |
184
|
|
|
} |
185
|
|
|
|
186
|
|
|
func (roundTripper *otelRoundTripper) requestAttributes(request *http.Request) []attribute.KeyValue { |
187
|
|
|
return append( |
188
|
|
|
append( |
189
|
|
|
[]attribute.KeyValue{}, |
190
|
|
|
roundTripper.attributes..., |
191
|
|
|
), |
192
|
|
|
roundTripper.extractRequestAttributes(request)..., |
193
|
|
|
) |
194
|
|
|
} |
195
|
|
|
|
196
|
|
|
func (roundTripper *otelRoundTripper) errorHook(ctx context.Context, err error, attributes []attribute.KeyValue) { |
197
|
|
|
roundTripper.metrics.inFlightCounter.Add(ctx, -1, attributes...) |
198
|
|
|
roundTripper.metrics.errorsCounter.Add(ctx, 1, attributes...) |
199
|
|
|
|
200
|
|
|
var timeoutErr net.Error |
201
|
|
|
if errors.As(err, &timeoutErr) && timeoutErr.Timeout() { |
202
|
|
|
roundTripper.metrics.timeoutsCounter.Add(ctx, 1, attributes...) |
203
|
|
|
} |
204
|
|
|
|
205
|
|
|
if strings.HasSuffix(err.Error(), context.Canceled.Error()) { |
206
|
|
|
roundTripper.metrics.canceledCounter.Add(ctx, 1, attributes...) |
207
|
|
|
} |
208
|
|
|
} |
209
|
|
|
|
210
|
|
|
func (roundTripper *otelRoundTripper) extractResponseAttributes(response *http.Response) []attribute.KeyValue { |
211
|
|
|
if response != nil { |
212
|
|
|
return []attribute.KeyValue{ |
213
|
|
|
semconv.HTTPStatusCodeKey.Int(response.StatusCode), |
214
|
|
|
semconv.HTTPFlavorKey.String(response.Proto), |
215
|
|
|
} |
216
|
|
|
} |
217
|
|
|
return nil |
218
|
|
|
} |
219
|
|
|
|
220
|
|
|
func (roundTripper *otelRoundTripper) extractRequestAttributes(request *http.Request) []attribute.KeyValue { |
221
|
|
|
if request != nil { |
222
|
|
|
return []attribute.KeyValue{ |
223
|
|
|
semconv.HTTPURLKey.String(request.URL.String()), |
224
|
|
|
semconv.HTTPMethodKey.String(request.Method), |
225
|
|
|
} |
226
|
|
|
} |
227
|
|
|
return nil |
228
|
|
|
} |
229
|
|
|
|
230
|
|
|
func (roundTripper *otelRoundTripper) extractCtx(request *http.Request) context.Context { |
231
|
|
|
if request != nil && request.Context() != nil { |
232
|
|
|
return request.Context() |
233
|
|
|
} |
234
|
|
|
return context.Background() |
235
|
|
|
} |
236
|
|
|
|