88 lines
2.3 KiB
Markdown
88 lines
2.3 KiB
Markdown
# Local Filesystem Hook for Logrus
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[](http://godoc.org/github.com/rifflock/lfshook)
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Sometimes developers like to write directly to a file on the filesystem. This is a hook for [`logrus`](https://github.com/sirupsen/logrus) which designed to allow users to do that. The log levels are dynamic at instantiation of the hook, so it is capable of logging at some or all levels.
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## Example
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```go
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import (
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"github.com/rifflock/lfshook"
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"github.com/sirupsen/logrus"
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)
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var Log *logrus.Logger
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func NewLogger() *logrus.Logger {
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if Log != nil {
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return Log
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}
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pathMap := lfshook.PathMap{
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logrus.InfoLevel: "/var/log/info.log",
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logrus.ErrorLevel: "/var/log/error.log",
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}
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Log = logrus.New()
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Log.Hooks.Add(lfshook.NewHook(
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pathMap,
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&logrus.JSONFormatter{},
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))
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return Log
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}
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```
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### Formatters
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`lfshook` will strip colors from any `TextFormatter` type formatters when writing to local file, because the color codes don't look great in file.
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If no formatter is provided via `lfshook.NewHook`, a default text formatter will be used.
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### Log rotation
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In order to enable automatic log rotation it's possible to provide an io.Writer instead of the path string of a log file.
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In combination with packages like [file-rotatelogs](https://github.com/lestrrat-go/file-rotatelogs) log rotation can easily be achieved.
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```go
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package main
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import (
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rotatelogs "github.com/lestrrat-go/file-rotatelogs"
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"github.com/rifflock/lfshook"
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"github.com/sirupsen/logrus"
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)
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var Log *logrus.Logger
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func NewLogger() *logrus.Logger {
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if Log != nil {
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return Log
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}
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path := "/var/log/go.log"
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writer := rotatelogs.New(
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path+".%Y%m%d%H%M",
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rotatelogs.WithLinkName(path),
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rotatelogs.WithMaxAge(time.Duration(86400)*time.Second),
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rotatelogs.WithRotationTime(time.Duration(604800)*time.Second),
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)
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logrus.Hooks.Add(lfshook.NewHook(
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lfshook.WriterMap{
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logrus.InfoLevel: writer,
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logrus.ErrorLevel: writer,
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},
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&logrus.JSONFormatter,
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))
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Log = logrus.New()
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Log.Hooks.Add(lfshook.NewHook(
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pathMap,
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&logrus.JSONFormatter{},
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))
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return Log
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}
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```
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### Note:
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User who run the go application must have read/write permissions to the selected log files. If the files do not exists yet, then user must have permission to the target directory.
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