http-server-status/vendor/github.com/rs/zerolog/syslog.go

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2021-09-20 09:28:00 +00:00
// +build !windows
// +build !binary_log
package zerolog
import (
"io"
)
// See http://cee.mitre.org/language/1.0-beta1/clt.html#syslog
// or https://www.rsyslog.com/json-elasticsearch/
const ceePrefix = "@cee:"
// SyslogWriter is an interface matching a syslog.Writer struct.
type SyslogWriter interface {
io.Writer
Debug(m string) error
Info(m string) error
Warning(m string) error
Err(m string) error
Emerg(m string) error
Crit(m string) error
}
type syslogWriter struct {
w SyslogWriter
prefix string
}
// SyslogLevelWriter wraps a SyslogWriter and call the right syslog level
// method matching the zerolog level.
func SyslogLevelWriter(w SyslogWriter) LevelWriter {
return syslogWriter{w, ""}
}
// SyslogCEEWriter wraps a SyslogWriter with a SyslogLevelWriter that adds a
// MITRE CEE prefix for JSON syslog entries, compatible with rsyslog
// and syslog-ng JSON logging support.
// See https://www.rsyslog.com/json-elasticsearch/
func SyslogCEEWriter(w SyslogWriter) LevelWriter {
return syslogWriter{w, ceePrefix}
}
func (sw syslogWriter) Write(p []byte) (n int, err error) {
var pn int
if sw.prefix != "" {
pn, err = sw.w.Write([]byte(sw.prefix))
if err != nil {
return pn, err
}
}
n, err = sw.w.Write(p)
return pn + n, err
}
// WriteLevel implements LevelWriter interface.
func (sw syslogWriter) WriteLevel(level Level, p []byte) (n int, err error) {
switch level {
case TraceLevel:
case DebugLevel:
err = sw.w.Debug(sw.prefix + string(p))
case InfoLevel:
err = sw.w.Info(sw.prefix + string(p))
case WarnLevel:
err = sw.w.Warning(sw.prefix + string(p))
case ErrorLevel:
err = sw.w.Err(sw.prefix + string(p))
case FatalLevel:
err = sw.w.Emerg(sw.prefix + string(p))
case PanicLevel:
err = sw.w.Crit(sw.prefix + string(p))
case NoLevel:
err = sw.w.Info(sw.prefix + string(p))
default:
panic("invalid level")
}
// Any CEE prefix is not part of the message, so we don't include its length
n = len(p)
return
}
// Call the underlying writer's Close method if it is an io.Closer. Otherwise
// does nothing.
func (sw syslogWriter) Close() error {
if c, ok := sw.w.(io.Closer); ok {
return c.Close()
}
return nil
}