runtime

README

logrus-runtime-formatter

Golang runtime package based automatic function, line and package fields for logrus. For further information and motivation behind the project please read this post.

tl;dr:

While we have been working on Pipeline we needed function, package and line number information to our log messages. We use Logrus and we could not find any similar extension so we have open sourced a Logrus runtime Formatter which automatically tags log messages with runtime/stack information without code modification.

Usage

You have to wrap your desired Formatter with the runtime.Formatter and it will do the job:

package main

import (
	"github.com/sirupsen/logrus"
	runtime "github.com/banzaicloud/logrus-runtime-formatter"
)

var log = logrus.New()

func init() {
	childFormatter := logrus.JSONFormatter{}
	runtimeFormatter := &runtime.Formatter{ChildFormatter: &childFormatter}
	log.Formatter = runtimeFormatter
	log.Level = logrus.DebugLevel
}

func main() {
	log.WithFields(logrus.Fields{
		"prefix": "main",
		"animal": "walrus",
		"number": 8,
	}).Debug("Started observing beach")

	log.WithFields(logrus.Fields{
		"prefix":      "sensor",
		"temperature": -4,
	}).Info("Temperature changes")
}

Test

make test

go test
PASS
ok  	github.com/banzaicloud/logrus-runtime-formatter	0.005s

Benchmark

make bench

go test -bench=. -benchmem
goos: darwin
goarch: amd64
pkg: github.com/banzaicloud/logrus-runtime-formatter
BenchmarkErrorRuntimeAndTextFormatter-4   	  500000	      3191 ns/op	  26.00 MB/s	     822 B/op	      15 allocs/op
BenchmarkErrorTextFormatter-4             	 1000000	      1556 ns/op	  43.06 MB/s	     454 B/op	      12 allocs/op
BenchmarkSmallRuntimeAndTextFormatter-4   	  500000	      3110 ns/op	  32.79 MB/s	     848 B/op	      13 allocs/op
BenchmarkSmallTextFormatter-4             	 1000000	      1435 ns/op	  59.90 MB/s	     480 B/op	      10 allocs/op
BenchmarkLargeRuntimeAndTextFormatter-4   	  100000	     11617 ns/op	  26.00 MB/s	    6445 B/op	      19 allocs/op
BenchmarkLargeTextFormatter-4             	  300000	      4984 ns/op	  57.38 MB/s	    1728 B/op	      12 allocs/op
BenchmarkSmallRuntimeAndJSONFormatter-4   	  200000	      5884 ns/op	  22.77 MB/s	    2368 B/op	      34 allocs/op
BenchmarkSmallJSONFormatter-4             	  500000	      3732 ns/op	  30.54 MB/s	    1648 B/op	      28 allocs/op
BenchmarkLargeRuntimeAndJSONFormatter-4   	  100000	     22673 ns/op	  18.96 MB/s	   11629 B/op	      87 allocs/op
BenchmarkLargeJSONFormatter-4             	  100000	     16407 ns/op	  24.99 MB/s	    6906 B/op	      78 allocs/op
PASS
ok  	github.com/banzaicloud/logrus-runtime-formatter	17.501s
------------------------------------------------------------

Documentation

Index

• Constants
• type Formatter
  • func (f *Formatter) Format(entry *logrus.Entry) ([]byte, error)

Constants

const FileKey = "file"

FileKey holds the file field

const FunctionKey = "function"

FunctionKey holds the function field

const LineKey = "line"

LineKey holds the line field

const PackageKey = "package"

PackageKey holds the package field

Types

type Formatter

type Formatter struct {
	ChildFormatter logrus.Formatter
	// When true, line number will be tagged to fields as well
	Line bool
	// When true, package name will be tagged to fields as well
	Package bool
	// When true, file name will be tagged to fields as well
	File bool
	// When true, only base name of the file will be tagged to fields
	BaseNameOnly bool
}

Formatter decorates log entries with function name and package name (optional) and line number (optional)

func (*Formatter) Format

func (f *Formatter) Format(entry *logrus.Entry) ([]byte, error)

Format the current log entry by adding the function name and line number of the caller.