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
|
// Go support for leveled logs, analogous to https://code.google.com/p/google-glog/
//
// Copyright 2013 Google Inc. All Rights Reserved.
//
// 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.
// File I/O for logs.
package klog
import (
"errors"
"fmt"
"os"
"os/user"
"path/filepath"
"runtime"
"strings"
"sync"
"time"
)
// MaxSize is the maximum size of a log file in bytes.
var MaxSize uint64 = 1024 * 1024 * 1800
// logDirs lists the candidate directories for new log files.
var logDirs []string
func createLogDirs() {
if logging.logDir != "" {
logDirs = append(logDirs, logging.logDir)
}
logDirs = append(logDirs, os.TempDir())
}
var (
pid = os.Getpid()
program = filepath.Base(os.Args[0])
host = "unknownhost"
userName = "unknownuser"
userNameOnce sync.Once
)
func init() {
if h, err := os.Hostname(); err == nil {
host = shortHostname(h)
}
}
func getUserName() string {
userNameOnce.Do(func() {
// On Windows, the Go 'user' package requires netapi32.dll.
// This affects Windows Nano Server:
// https://github.com/golang/go/issues/21867
// Fallback to using environment variables.
if runtime.GOOS == "windows" {
u := os.Getenv("USERNAME")
if len(u) == 0 {
return
}
// Sanitize the USERNAME since it may contain filepath separators.
u = strings.Replace(u, `\`, "_", -1)
// user.Current().Username normally produces something like 'USERDOMAIN\USERNAME'
d := os.Getenv("USERDOMAIN")
if len(d) != 0 {
userName = d + "_" + u
} else {
userName = u
}
} else {
current, err := user.Current()
if err == nil {
userName = current.Username
}
}
})
return userName
}
// shortHostname returns its argument, truncating at the first period.
// For instance, given "www.google.com" it returns "www".
func shortHostname(hostname string) string {
if i := strings.Index(hostname, "."); i >= 0 {
return hostname[:i]
}
return hostname
}
// logName returns a new log file name containing tag, with start time t, and
// the name for the symlink for tag.
func logName(tag string, t time.Time) (name, link string) {
name = fmt.Sprintf("%s.%s.%s.log.%s.%04d%02d%02d-%02d%02d%02d.%d",
program,
host,
getUserName(),
tag,
t.Year(),
t.Month(),
t.Day(),
t.Hour(),
t.Minute(),
t.Second(),
pid)
return name, program + "." + tag
}
var onceLogDirs sync.Once
// create creates a new log file and returns the file and its filename, which
// contains tag ("INFO", "FATAL", etc.) and t. If the file is created
// successfully, create also attempts to update the symlink for that tag, ignoring
// errors.
// The startup argument indicates whether this is the initial startup of klog.
// If startup is true, existing files are opened for appending instead of truncated.
func create(tag string, t time.Time, startup bool) (f *os.File, filename string, err error) {
if logging.logFile != "" {
f, err := openOrCreate(logging.logFile, startup)
if err == nil {
return f, logging.logFile, nil
}
return nil, "", fmt.Errorf("log: unable to create log: %v", err)
}
onceLogDirs.Do(createLogDirs)
if len(logDirs) == 0 {
return nil, "", errors.New("log: no log dirs")
}
name, link := logName(tag, t)
var lastErr error
for _, dir := range logDirs {
fname := filepath.Join(dir, name)
f, err := openOrCreate(fname, startup)
if err == nil {
symlink := filepath.Join(dir, link)
os.Remove(symlink) // ignore err
os.Symlink(name, symlink) // ignore err
return f, fname, nil
}
lastErr = err
}
return nil, "", fmt.Errorf("log: cannot create log: %v", lastErr)
}
// The startup argument indicates whether this is the initial startup of klog.
// If startup is true, existing files are opened for appending instead of truncated.
func openOrCreate(name string, startup bool) (*os.File, error) {
if startup {
f, err := os.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
return f, err
}
f, err := os.Create(name)
return f, err
}
|
