cloudflared-mirror/vendor/github.com/rifflock/lfshook/lfshook.go

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// Package lfshook is hook for sirupsen/logrus that used for writing the logs to local files.
package lfshook
import (
"fmt"
"github.com/sirupsen/logrus"
"io"
"log"
"os"
"path/filepath"
"reflect"
"sync"
)
// We are logging to file, strip colors to make the output more readable.
var defaultFormatter = &logrus.TextFormatter{DisableColors: true}
// PathMap is map for mapping a log level to a file's path.
// Multiple levels may share a file, but multiple files may not be used for one level.
type PathMap map[logrus.Level]string
// WriterMap is map for mapping a log level to an io.Writer.
// Multiple levels may share a writer, but multiple writers may not be used for one level.
type WriterMap map[logrus.Level]io.Writer
// LfsHook is a hook to handle writing to local log files.
type LfsHook struct {
paths PathMap
writers WriterMap
levels []logrus.Level
lock *sync.Mutex
formatter logrus.Formatter
defaultPath string
defaultWriter io.Writer
hasDefaultPath bool
hasDefaultWriter bool
}
// NewHook returns new LFS hook.
// Output can be a string, io.Writer, WriterMap or PathMap.
// If using io.Writer or WriterMap, user is responsible for closing the used io.Writer.
func NewHook(output interface{}, formatter logrus.Formatter) *LfsHook {
hook := &LfsHook{
lock: new(sync.Mutex),
}
hook.SetFormatter(formatter)
switch output.(type) {
case string:
hook.SetDefaultPath(output.(string))
break
case io.Writer:
hook.SetDefaultWriter(output.(io.Writer))
break
case PathMap:
hook.paths = output.(PathMap)
for level := range output.(PathMap) {
hook.levels = append(hook.levels, level)
}
break
case WriterMap:
hook.writers = output.(WriterMap)
for level := range output.(WriterMap) {
hook.levels = append(hook.levels, level)
}
break
default:
panic(fmt.Sprintf("unsupported level map type: %v", reflect.TypeOf(output)))
}
return hook
}
// SetFormatter sets the format that will be used by hook.
// If using text formatter, this method will disable color output to make the log file more readable.
func (hook *LfsHook) SetFormatter(formatter logrus.Formatter) {
hook.lock.Lock()
defer hook.lock.Unlock()
if formatter == nil {
formatter = defaultFormatter
} else {
switch formatter.(type) {
case *logrus.TextFormatter:
textFormatter := formatter.(*logrus.TextFormatter)
textFormatter.DisableColors = true
}
}
hook.formatter = formatter
}
// SetDefaultPath sets default path for levels that don't have any defined output path.
func (hook *LfsHook) SetDefaultPath(defaultPath string) {
hook.lock.Lock()
defer hook.lock.Unlock()
hook.defaultPath = defaultPath
hook.hasDefaultPath = true
}
// SetDefaultWriter sets default writer for levels that don't have any defined writer.
func (hook *LfsHook) SetDefaultWriter(defaultWriter io.Writer) {
hook.lock.Lock()
defer hook.lock.Unlock()
hook.defaultWriter = defaultWriter
hook.hasDefaultWriter = true
}
// Fire writes the log file to defined path or using the defined writer.
// User who run this function needs write permissions to the file or directory if the file does not yet exist.
func (hook *LfsHook) Fire(entry *logrus.Entry) error {
hook.lock.Lock()
defer hook.lock.Unlock()
if hook.writers != nil || hook.hasDefaultWriter {
return hook.ioWrite(entry)
} else if hook.paths != nil || hook.hasDefaultPath {
return hook.fileWrite(entry)
}
return nil
}
// Write a log line to an io.Writer.
func (hook *LfsHook) ioWrite(entry *logrus.Entry) error {
var (
writer io.Writer
msg []byte
err error
ok bool
)
if writer, ok = hook.writers[entry.Level]; !ok {
if hook.hasDefaultWriter {
writer = hook.defaultWriter
} else {
return nil
}
}
// use our formatter instead of entry.String()
msg, err = hook.formatter.Format(entry)
if err != nil {
log.Println("failed to generate string for entry:", err)
return err
}
_, err = writer.Write(msg)
return err
}
// Write a log line directly to a file.
func (hook *LfsHook) fileWrite(entry *logrus.Entry) error {
var (
fd *os.File
path string
msg []byte
err error
ok bool
)
if path, ok = hook.paths[entry.Level]; !ok {
if hook.hasDefaultPath {
path = hook.defaultPath
} else {
return nil
}
}
dir := filepath.Dir(path)
os.MkdirAll(dir, os.ModePerm)
fd, err = os.OpenFile(path, os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0666)
if err != nil {
log.Println("failed to open logfile:", path, err)
return err
}
defer fd.Close()
// use our formatter instead of entry.String()
msg, err = hook.formatter.Format(entry)
if err != nil {
log.Println("failed to generate string for entry:", err)
return err
}
fd.Write(msg)
return nil
}
// Levels returns configured log levels.
func (hook *LfsHook) Levels() []logrus.Level {
return logrus.AllLevels
}