glogr

README

Minimal Go logging using glog

This package implements the logr interface in terms of Google's glog. This provides a relatively minimalist API to logging in Go, backed by a well-proven implementation.

Documentation

Overview

Package glogr implements github.com/go-logr/logr.Logger in terms of github.com/golang/glog.

Index

• func New() logr.Logger
• func NewWithOptions(opts Options) logr.Logger
• type MessageClass
• type Options

Examples

• New
• New (WithName)
• NewWithOptions

Functions

func New

func New() logr.Logger

New returns a logr.Logger which is implemented by glog.

Example

package main

import (
	"errors"
	"flag"
	"os"
	"sync"

	"github.com/go-logr/glogr"
)

var glogInit = sync.Once{}

func initGlog() {
	glogInit.Do(func() {
		_ = flag.Set("v", "1")
		_ = flag.Set("logtostderr", "true")
		flag.Parse()
	})
	os.Stderr = os.Stdout
}

var errSome = errors.New("some error")

func main() {
	initGlog()
	log := glogr.New()
	log.Info("info message with default options")
	log.Error(errSome, "error message with default options")
	log.Info("invalid key", 42, "answer")
	log.Info("missing value", "answer")
	// I1015 08:59:26.952954 2385059 example_test.go:44] "level"=0 "msg"="info message with default options"
	// E1015 08:59:26.953000 2385059 example_test.go:45] "msg"="error message with default options" "error"="some error"
	// I1015 08:59:26.953005 2385059 example_test.go:46] "level"=0 "msg"="invalid key" "<non-string-key: 42>"="answer"
	// I1015 08:59:26.953013 2385059 example_test.go:47] "level"=0 "msg"="missing value" "answer"="<no-value>"
}

Example (WithName)

package main

import (
	"flag"
	"os"
	"sync"

	"github.com/go-logr/glogr"
)

var glogInit = sync.Once{}

func initGlog() {
	glogInit.Do(func() {
		_ = flag.Set("v", "1")
		_ = flag.Set("logtostderr", "true")
		flag.Parse()
	})
	os.Stderr = os.Stdout
}

func main() {
	initGlog()
	log := glogr.New()
	log.WithName("hello").WithName("world").Info("thanks for the fish")
	// I1015 08:59:26.953089 2385059 example_test.go:54] hello/world: "level"=0 "msg"="thanks for the fish"
}

func NewWithOptions

func NewWithOptions(opts Options) logr.Logger

NewWithOptions returns a logr.Logger which is implemented by glog.

Example

package main

import (
	"flag"
	"os"
	"sync"

	"github.com/go-logr/glogr"
)

var glogInit = sync.Once{}

func initGlog() {
	glogInit.Do(func() {
		_ = flag.Set("v", "1")
		_ = flag.Set("logtostderr", "true")
		flag.Parse()
	})
	os.Stderr = os.Stdout
}

func main() {
	initGlog()
	log := glogr.NewWithOptions(glogr.Options{LogCaller: glogr.Error})
	log.Info("Info log with LogCaller=Error")
	log.Error(nil, "Error log with LogCaller=All")
	// I1015 09:10:36.754010 2392854 example_test.go:64] "level"=0 "msg"="Info log with LogCaller=Error"
	// E1015 09:10:36.754057 2392854 example_test.go:65] "caller"={"file":"example_test.go","line":65} "msg"="Error log with LogCaller=All" "error"=null
}

Types

type MessageClass

type MessageClass int

MessageClass indicates which category or categories of messages to consider.

const (
	// None ignores all message classes.
	None MessageClass = iota
	// All considers all message classes.
	All
	// Info only considers info messages.
	Info
	// Error only considers error messages.
	Error
)

type Options

type Options struct {
	// Depth biases the assumed number of call frames to the "true" caller.
	// This is useful when the calling code calls a function which then calls
	// glogr (e.g. a logging shim to another API).  Values less than zero will
	// be treated as zero.
	Depth int

	// LogCaller tells glogr to add a "caller" key to some or all log lines.
	// The glog implementation always logs this information in its per-line
	// header, whether this option is set or not.
	LogCaller MessageClass
}

Options carries parameters which influence the way logs are generated.