-
Notifications
You must be signed in to change notification settings - Fork 0
/
slog_gelf_handler.go
184 lines (153 loc) · 3.75 KB
/
slog_gelf_handler.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
package logger
import (
"context"
"fmt"
"io"
"log/slog"
"os"
"github.com/mdouchement/logger/syslog"
)
type (
// A SlogGELFOption holds SlogGELFHandler's options.
SlogGELFOption struct {
Level slog.Level
Hostname string
}
// A SlogGELFHandler is GELF formatter for log/slog.
SlogGELFHandler struct {
opt *SlogGELFOption
writer io.Writer
parent *SlogGELFHandler
prefix string
group string
attrs []slog.Attr
}
)
// NewSlogGELFHandler returns a new SlogGELFHandler.
func NewSlogGELFHandler(w io.Writer, o *SlogGELFOption) *SlogGELFHandler {
var err error
if o == nil {
o = &SlogGELFOption{Level: slog.LevelInfo}
}
if o.Hostname == "" {
o.Hostname, err = os.Hostname()
if err != nil {
o.Hostname = "localhost"
}
}
return &SlogGELFHandler{
opt: o,
writer: w,
}
}
// Enabled reports whether the handler handles records at the given level.
func (h *SlogGELFHandler) Enabled(_ context.Context, l slog.Level) bool {
return l >= h.opt.Level
}
// WithAttrs returns a new Handler whose attributes consist of
// both the receiver's attributes and the arguments.
func (h *SlogGELFHandler) WithAttrs(attrs []slog.Attr) slog.Handler {
if len(attrs) == 0 {
return h
}
nh := h.Clone() // Since h is cloned, it's just read, never edited so it's safe.
nh.attrs = make([]slog.Attr, 0, len(attrs))
for _, attr := range attrs {
if attr.Key == KeyPrefix {
nh.prefix += attr.Value.String()
continue
}
nh.attrs = append(nh.attrs, attr)
}
return nh
}
// WithGroup returns a new Handler with the given group appended to
// the receiver's existing groups.
func (h *SlogGELFHandler) WithGroup(name string) slog.Handler {
if name == "" {
return h
}
nh := h.Clone() // Since h is cloned, it's just read, never edited so it's safe.
nh.group = name
return nh
}
// Handle handles the Record.
func (h *SlogGELFHandler) Handle(_ context.Context, record slog.Record) error {
gelf := NewBufferGELF()
// Get all parents in a list.
ilineage := make([]*SlogGELFHandler, 0, 100)
p := h
for p != nil {
ilineage = append(ilineage, p)
p = p.parent
}
// Process handler's groups/attrs.
var gprefix string
for i := len(ilineage) - 1; i >= 0; i-- {
p = ilineage[i]
if p.group != "" {
gprefix += p.group + delimiter
}
for _, attr := range ilineage[i].attrs {
gelf.Add(gprefix+attr.Key, attr.Value.Any())
}
}
// Process record's groups/attrs.
if record.NumAttrs() > 0 {
record.Attrs(func(attr slog.Attr) bool {
gelfrecord(gelf, gprefix, attr)
return true
})
}
// Main fields.
gelf.Host(h.opt.Hostname)
gelf.Timestamp(record.Time)
gelf.Level(h.priorities(record.Level))
if h.prefix != "" {
record.Message = fmt.Sprintf("%s %s", h.prefix, record.Message)
}
gelf.Message(record.Message)
gelf.Add("level_name", record.Level.String())
// m["_file"]
// m["_line"]
_, err := h.writer.Write(gelf.Complete(true))
return err
}
// Clone clones the entry, it creates a new instance and linking the parent to it.
func (h *SlogGELFHandler) Clone() *SlogGELFHandler {
nh := &SlogGELFHandler{
parent: h,
opt: h.opt,
prefix: h.prefix,
writer: h.writer,
}
return nh
}
func (SlogGELFHandler) priorities(level slog.Level) int32 {
var p syslog.Priority
switch level {
case slog.LevelError:
p = syslog.LOG_ERR
case slog.LevelWarn:
p = syslog.LOG_WARNING
case slog.LevelInfo:
p = syslog.LOG_INFO
case slog.LevelDebug:
p = syslog.LOG_DEBUG
}
return int32(p)
}
func gelfrecord(gelf *BufferGELF, p string, attr slog.Attr) {
if attr.Value.Kind() != slog.KindGroup {
gelf.Add(p+attr.Key, attr.Value.Any())
return
}
p += attr.Key + delimiter
for _, a := range attr.Value.Group() {
if a.Value.Kind() == slog.KindGroup {
gelfrecord(gelf, p, a)
continue
}
gelf.Add(p+a.Key, a.Value.Any())
}
}