Codebase list golang-github-go-kit-kit / dd0f49f
Add StdlibWriter adapter - Allows Loggers to be passed to log.SetOutput - Extracts date, time, file, message keyvals - I have no idea how to support SetPrefix :( Peter Bourgon 9 years ago
2 changed file(s) with 203 addition(s) and 0 deletion(s). Raw diff Collapse all Expand all
+100
-0
log/stdlib_writer.go less more
0 package log
1
2 import (
3 "io"
4 "regexp"
5 )
6
7 // StdlibWriter wraps a Logger and allows it to be passed to the stdlib
8 // logger's SetOutput. It will extract date/timestamps, filenames, and
9 // messages, and place them under relevant keys.
10 type StdlibWriter struct {
11 Logger
12 timestampKey string
13 fileKey string
14 messageKey string
15 }
16
17 // StdlibWriterOption sets a parameter for the StdlibWriter.
18 type StdlibWriterOption func(*StdlibWriter)
19
20 // TimestampKey sets the key for the timestamp field. By default, it's "ts".
21 func TimestampKey(key string) StdlibWriterOption {
22 return func(w *StdlibWriter) { w.timestampKey = key }
23 }
24
25 // FileKey sets the key for the file and line field. By default, it's "file".
26 func FileKey(key string) StdlibWriterOption {
27 return func(w *StdlibWriter) { w.fileKey = key }
28 }
29
30 // MessageKey sets the key for the actual log message. By default, it's "msg".
31 func MessageKey(key string) StdlibWriterOption {
32 return func(w *StdlibWriter) { w.messageKey = key }
33 }
34
35 // NewStdlibWriter returns a new StdlibWriter wrapper around the passed
36 // logger. It's designed to be passed to log.SetOutput.
37 func NewStdlibWriter(logger Logger, options ...StdlibWriterOption) io.Writer {
38 w := StdlibWriter{
39 Logger: logger,
40 timestampKey: "ts",
41 fileKey: "file",
42 messageKey: "msg",
43 }
44 for _, option := range options {
45 option(&w)
46 }
47 return w
48 }
49
50 func (w StdlibWriter) Write(p []byte) (int, error) {
51 result := subexps(p)
52 keyvals := []interface{}{}
53 var timestamp string
54 if date, ok := result["date"]; ok && date != "" {
55 timestamp = date
56 }
57 if time, ok := result["time"]; ok && time != "" {
58 if timestamp != "" {
59 timestamp += " "
60 }
61 timestamp += time
62 }
63 if timestamp != "" {
64 keyvals = append(keyvals, w.timestampKey, timestamp)
65 }
66 if file, ok := result["file"]; ok && file != "" {
67 keyvals = append(keyvals, w.fileKey, file)
68 }
69 if msg, ok := result["msg"]; ok {
70 keyvals = append(keyvals, w.messageKey, msg)
71 }
72 if err := w.Logger.Log(keyvals...); err != nil {
73 return 0, err
74 }
75 return len(p), nil
76 }
77
78 const (
79 logRegexpDate = `(?P<date>[0-9]{4}/[0-9]{2}/[0-9]{2})?[ ]?`
80 logRegexpTime = `(?P<time>[0-9]{2}:[0-9]{2}:[0-9]{2}(\.[0-9]+)?)?[ ]?`
81 logRegexpFile = `(?P<file>[^:]+:[0-9]+)?`
82 logRegexpMsg = `(: )?(?P<msg>.*)`
83 )
84
85 var (
86 logRegexp = regexp.MustCompile(logRegexpDate + logRegexpTime + logRegexpFile + logRegexpMsg)
87 )
88
89 func subexps(line []byte) map[string]string {
90 m := logRegexp.FindSubmatch(line)
91 if len(m) < len(logRegexp.SubexpNames()) {
92 return map[string]string{}
93 }
94 result := map[string]string{}
95 for i, name := range logRegexp.SubexpNames() {
96 result[name] = string(m[i])
97 }
98 return result
99 }
+103
-0
log/stdlib_writer_test.go less more
0 package log
1
2 import (
3 "bytes"
4 "fmt"
5 "testing"
6 )
7
8 func TestStdLibWriterExtraction(t *testing.T) {
9 buf := &bytes.Buffer{}
10 logger := NewPrefixLogger(buf)
11 writer := NewStdlibWriter(logger)
12 for input, want := range map[string]string{
13 "hello": "msg=hello\n",
14 "2009/01/23: hello": "ts=2009/01/23 msg=hello\n",
15 "2009/01/23 01:23:23: hello": "ts=2009/01/23 01:23:23 msg=hello\n",
16 "01:23:23: hello": "ts=01:23:23 msg=hello\n",
17 "2009/01/23 01:23:23.123123: hello": "ts=2009/01/23 01:23:23.123123 msg=hello\n",
18 "2009/01/23 01:23:23.123123 /a/b/c/d.go:23: hello": "ts=2009/01/23 01:23:23.123123 file=/a/b/c/d.go:23 msg=hello\n",
19 "01:23:23.123123 /a/b/c/d.go:23: hello": "ts=01:23:23.123123 file=/a/b/c/d.go:23 msg=hello\n",
20 "2009/01/23 01:23:23 /a/b/c/d.go:23: hello": "ts=2009/01/23 01:23:23 file=/a/b/c/d.go:23 msg=hello\n",
21 "2009/01/23 /a/b/c/d.go:23: hello": "ts=2009/01/23 file=/a/b/c/d.go:23 msg=hello\n",
22 "/a/b/c/d.go:23: hello": "file=/a/b/c/d.go:23 msg=hello\n",
23 } {
24 buf.Reset()
25 fmt.Fprintf(writer, input)
26 if have := buf.String(); want != have {
27 t.Errorf("%q: want %#v, have %#v", input, want, have)
28 }
29 }
30 }
31
32 func TestStdlibWriterSubexps(t *testing.T) {
33 for input, wantMap := range map[string]map[string]string{
34 "hello world": map[string]string{
35 "date": "",
36 "time": "",
37 "file": "",
38 "msg": "hello world",
39 },
40 "2009/01/23: hello world": map[string]string{
41 "date": "2009/01/23",
42 "time": "",
43 "file": "",
44 "msg": "hello world",
45 },
46 "2009/01/23 01:23:23: hello world": map[string]string{
47 "date": "2009/01/23",
48 "time": "01:23:23",
49 "file": "",
50 "msg": "hello world",
51 },
52 "01:23:23: hello world": map[string]string{
53 "date": "",
54 "time": "01:23:23",
55 "file": "",
56 "msg": "hello world",
57 },
58 "2009/01/23 01:23:23.123123: hello world": map[string]string{
59 "date": "2009/01/23",
60 "time": "01:23:23.123123",
61 "file": "",
62 "msg": "hello world",
63 },
64 "2009/01/23 01:23:23.123123 /a/b/c/d.go:23: hello world": map[string]string{
65 "date": "2009/01/23",
66 "time": "01:23:23.123123",
67 "file": "/a/b/c/d.go:23",
68 "msg": "hello world",
69 },
70 "01:23:23.123123 /a/b/c/d.go:23: hello world": map[string]string{
71 "date": "",
72 "time": "01:23:23.123123",
73 "file": "/a/b/c/d.go:23",
74 "msg": "hello world",
75 },
76 "2009/01/23 01:23:23 /a/b/c/d.go:23: hello world": map[string]string{
77 "date": "2009/01/23",
78 "time": "01:23:23",
79 "file": "/a/b/c/d.go:23",
80 "msg": "hello world",
81 },
82 "2009/01/23 /a/b/c/d.go:23: hello world": map[string]string{
83 "date": "2009/01/23",
84 "time": "",
85 "file": "/a/b/c/d.go:23",
86 "msg": "hello world",
87 },
88 "/a/b/c/d.go:23: hello world": map[string]string{
89 "date": "",
90 "time": "",
91 "file": "/a/b/c/d.go:23",
92 "msg": "hello world",
93 },
94 } {
95 haveMap := subexps([]byte(input))
96 for key, want := range wantMap {
97 if have := haveMap[key]; want != have {
98 t.Errorf("%q: %q: want %q, have %q", input, key, want, have)
99 }
100 }
101 }
102 }