Merge pull request #924 from bunyk/master

Add hook to send logs to custom writer #678
This commit is contained in:
Sébastien Lavoie 2020-02-26 17:31:00 -05:00 committed by GitHub
commit 24566a3fc4
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4 changed files with 116 additions and 1 deletions

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@ -85,10 +85,15 @@ func NewEntry(logger *Logger) *Entry {
} }
} }
// Returns the bytes representation of this entry from the formatter.
func (entry *Entry) Bytes() ([]byte, error) {
return entry.Logger.Formatter.Format(entry)
}
// Returns the string representation from the reader and ultimately the // Returns the string representation from the reader and ultimately the
// formatter. // formatter.
func (entry *Entry) String() (string, error) { func (entry *Entry) String() (string, error) {
serialized, err := entry.Logger.Formatter.Format(entry) serialized, err := entry.Bytes()
if err != nil { if err != nil {
return "", err return "", err
} }

43
hooks/writer/README.md Normal file
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@ -0,0 +1,43 @@
# Writer Hooks for Logrus
Send logs of given levels to any object with `io.Writer` interface.
## Usage
If you want for example send high level logs to `Stderr` and
logs of normal execution to `Stdout`, you could do it like this:
```go
package main
import (
"io/ioutil"
"os"
log "github.com/sirupsen/logrus"
"github.com/sirupsen/logrus/hooks/writer"
)
func main() {
log.SetOutput(ioutil.Discard) // Send all logs to nowhere by default
log.AddHook(&writer.Hook{ // Send logs with level higher than warning to stderr
Writer: os.Stderr,
LogLevels: []log.Level{
log.PanicLevel,
log.FatalLevel,
log.ErrorLevel,
log.WarnLevel,
},
})
log.AddHook(&writer.Hook{ // Send info and debug logs to stdout
Writer: os.Stdout,
LogLevels: []log.Level{
log.InfoLevel,
log.DebugLevel,
},
})
log.Info("This will go to stdout")
log.Warn("This will go to stderr")
}
```

29
hooks/writer/writer.go Normal file
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@ -0,0 +1,29 @@
package writer
import (
"io"
log "github.com/sirupsen/logrus"
)
// Hook is a hook that writes logs of specified LogLevels to specified Writer
type Hook struct {
Writer io.Writer
LogLevels []log.Level
}
// Fire will be called when some logging function is called with current hook
// It will format log entry to string and write it to appropriate writer
func (hook *Hook) Fire(entry *log.Entry) error {
line, err := entry.Bytes()
if err != nil {
return err
}
_, err = hook.Writer.Write(line)
return err
}
// Levels define on which log levels this hook would trigger
func (hook *Hook) Levels() []log.Level {
return hook.LogLevels
}

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@ -0,0 +1,38 @@
package writer
import (
"bytes"
"io/ioutil"
"testing"
log "github.com/sirupsen/logrus"
"github.com/stretchr/testify/assert"
)
func TestDifferentLevelsGoToDifferentWriters(t *testing.T) {
var a, b bytes.Buffer
log.SetFormatter(&log.TextFormatter{
DisableTimestamp: true,
DisableColors: true,
})
log.SetOutput(ioutil.Discard) // Send all logs to nowhere by default
log.AddHook(&Hook{
Writer: &a,
LogLevels: []log.Level{
log.WarnLevel,
},
})
log.AddHook(&Hook{ // Send info and debug logs to stdout
Writer: &b,
LogLevels: []log.Level{
log.InfoLevel,
},
})
log.Warn("send to a")
log.Info("send to b")
assert.Equal(t, a.String(), "level=warning msg=\"send to a\"\n")
assert.Equal(t, b.String(), "level=info msg=\"send to b\"\n")
}