-
Notifications
You must be signed in to change notification settings - Fork 19
/
attributes.go
228 lines (197 loc) · 6.49 KB
/
attributes.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
package telemetry
import (
"fmt"
"reflect"
"strings"
"time"
"go.opentelemetry.io/otel/attribute"
)
const DropSpanKey = "span.drop"
// DropSpan informs the sampler to skip this event if theirs no links tied to it.
func DropSpan() attribute.KeyValue {
return attribute.Bool(DropSpanKey, true)
}
const MoovKnownIssueKey = "moov.known_issue"
// AttributeMoovKnownIssue is an attribute to mark a trace as a previously observed issue.
// IMPORTANT: if a trace has this attribute it will NOT fire a critical PD alert defined in
// https://github.com/moovfinancial/infra/blob/master/terraform-modules/apps/go-service/honeycomb.tf#L42
func AttributeMoovKnownIssue() attribute.KeyValue {
return attribute.Bool(MoovKnownIssueKey, true)
}
// StructAttributes creates an attribute.KeyValue for each field in the struct that has an "otel" tag defined.
// Nested structs will also be included, with attribute names formatted as "parent_attribute.nested_field_attribute".
func StructAttributes(s interface{}) (kv []attribute.KeyValue) {
rVal := reflect.ValueOf(s)
if !rVal.IsValid() {
return kv // ignore values that can't be handled by reflection
}
return structAttributes(rVal, "") // no prefix for top level
}
func structAttributes(rVal reflect.Value, prefix string) (kv []attribute.KeyValue) {
defer func() { // recover from panics
if recovered := recover(); recovered != nil {
return
}
}()
// if rVal is an interface or pointer, get the underlying value
if rVal.Kind() == reflect.Interface || rVal.Kind() == reflect.Pointer {
if rVal.IsNil() {
return kv
}
// get the underlying value from this interface or pointer
rVal = rVal.Elem()
}
if rVal.Kind() != reflect.Struct {
return kv // only structs have tags to parse
}
for i := 0; i < rVal.NumField(); i++ {
field := rVal.Type().Field(i)
// skip non-exported fields
if !field.IsExported() && !field.Anonymous {
continue // exported fields only
}
otelTag := parseTag(prefix, field.Tag)
if otelTag == nil {
continue
}
kv = append(kv, createAttributes(rVal.Field(i), otelTag)...)
}
return kv
}
type otelTag struct {
attributeName string
omitEmpty bool
}
func parseTag(prefix string, stag reflect.StructTag) *otelTag {
tagParts := strings.Split(stag.Get(AttributeTag), ",")
attributeName := tagParts[0] // strings.Split is guaranteed to always return at least 1 element
if attributeName == "" {
return nil
}
if prefix != "" {
attributeName = fmt.Sprintf("%s.%s", prefix, attributeName)
}
omitEmpty := false
if len(tagParts) > 1 && tagParts[1] == "omitempty" {
omitEmpty = true
}
return &otelTag{
attributeName: attributeName,
omitEmpty: omitEmpty,
}
}
type stringValuer interface {
Value() string
}
type intValuer interface {
Value() int
}
func createAttributes(val reflect.Value, tag *otelTag) (kv []attribute.KeyValue) {
if tag.omitEmpty && val.IsZero() {
return kv
}
switch val.Kind() {
case reflect.String:
kv = append(kv, attribute.String(tag.attributeName, val.String()))
case reflect.Bool:
kv = append(kv, attribute.Bool(tag.attributeName, val.Bool()))
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
kv = append(kv, attribute.Int64(tag.attributeName, val.Int()))
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
kv = append(kv, attribute.Int64(tag.attributeName, int64(val.Uint())))
case reflect.Float32, reflect.Float64:
kv = append(kv, attribute.Float64(tag.attributeName, val.Float()))
case reflect.Complex64, reflect.Complex128:
complexVal := val.Complex()
kv = append(kv,
attribute.Float64(tag.attributeName+"_real", real(complexVal)),
attribute.Float64(tag.attributeName+"_imag", imag(complexVal)),
)
case reflect.Map:
// check map key type
if val.Len() == 0 || len(val.MapKeys()) == 0 {
break
}
keyKind := val.MapKeys()[0].Kind()
if keyKind == reflect.Pointer {
keyKind = val.MapKeys()[0].Elem().Kind()
}
if !supportedMapKeyKinds[keyKind] {
break
}
mapIter := val.MapRange()
count := 0
for mapIter.Next() {
// only support simple map key types
if count == MaxArrayAttributes {
break
}
key := mapIter.Key()
if key.Kind() == reflect.Pointer {
key = key.Elem()
}
kv = append(kv, createAttributes(mapIter.Value(), &otelTag{
attributeName: fmt.Sprintf("%s.%v", tag.attributeName, key.Interface()),
omitEmpty: false,
})...)
count++
}
case reflect.Array, reflect.Slice:
for i := 0; i < val.Len(); i++ {
if i == MaxArrayAttributes {
break
}
kv = append(kv, createAttributes(val.Index(i), &otelTag{
attributeName: fmt.Sprintf("%s.%d", tag.attributeName, i),
omitEmpty: false,
})...)
}
case reflect.Struct:
// if this is a non-zero time.Time, format as string and append to attributes
if t, ok := val.Interface().(time.Time); ok && !t.IsZero() {
kv = append(kv, attribute.String(tag.attributeName, t.Format(time.RFC3339)))
} else if t, ok := val.Interface().(stringValuer); ok {
stringValue := t.Value()
kv = append(kv, attribute.String(tag.attributeName, stringValue))
} else if t, ok := val.Interface().(intValuer); ok {
intValue := t.Value()
kv = append(kv, attribute.Int(tag.attributeName, intValue))
} else { // otherwise recursively handle the struct
kv = append(kv, structAttributes(val, tag.attributeName)...)
}
case reflect.Pointer:
// before we check the value element, see if the pointer implements any of
// our known interfaces
if t, ok := val.Interface().(stringValuer); ok {
stringValue := t.Value()
kv = append(kv, attribute.String(tag.attributeName, stringValue))
} else if t, ok := val.Interface().(intValuer); ok {
intValue := t.Value()
kv = append(kv, attribute.Int(tag.attributeName, intValue))
} else {
kv = append(kv, createAttributes(val.Elem(), tag)...)
}
case reflect.Chan, reflect.Func, reflect.Interface, reflect.Uintptr,
reflect.UnsafePointer, reflect.Invalid:
return // not supported
}
return kv
}
// supportedMapKeyKinds defines the map key types that are supported for attribute names.
// Only types that can be easily represented as strings are allowed to be used in attribute names.
var supportedMapKeyKinds = map[reflect.Kind]bool{
reflect.Bool: true,
reflect.Int: true,
reflect.Int8: true,
reflect.Int16: true,
reflect.Int32: true,
reflect.Int64: true,
reflect.Uint: true,
reflect.Uint8: true,
reflect.Uint16: true,
reflect.Uint32: true,
reflect.Uint64: true,
reflect.Float32: true,
reflect.Float64: true,
reflect.String: true,
}