logger

go-logger

This Go package is used to offer a unified logging interface among projects.

Install

go get github.com/coopnorge/go-logger

Import

import "github.com/coopnorge/go-logger"

Default behavior

By default, all logs will include:

• Log level
• Full path to file which called the logger, and line number
• Signature of the function that called the logger
• Timestamp of the log entry

Example log entry with default settings:

package main

import "github.com/coopnorge/go-logger"

func main() {
	logger.Warn("something went wrong")
	// Output:
	// {"file":"/Users/anonymous/Projects/my-project/main.go:7","function":"main.main","level":"warning","msg":"something went wrong","time":"2022-02-17T15:04:06+01:00"}
}

Example usage

See logger_examples_test.go for more examples.

Using global logger

package main

import "github.com/coopnorge/go-logger"

func main() {
	logger.Info("this won't be logged because the default log level is higher than info")
	logger.Warn("but this will be logged")
	// Output:
	// {"level":"warning","msg":"but this will be logged","time":"2022-02-17T11:01:28+01:00"}
}

Setting log level

package main

import "github.com/coopnorge/go-logger"

func main() {
	// global logger
	logger.Info("this won't be logged because the default log level is higher than info")
	logger.ConfigureGlobalLogger(logger.WithLevel(logger.LevelInfo))
	logger.Info("now this will be logged")
	// Output:
	// {"level":"info","msg":"now this will be logged","time":"2022-02-17T10:54:54+01:00"}

	// logger instance
	prodLogger := logger.New(logger.WithLevel(logger.LevelWarn))
	prodLogger.Info("this won't be logged because prodLogger's level is set to Warn...")
	prodLogger.Error("...but this will, because Error >= Warn")
	// Output:
	// {"level":"error","msg":"...but this will, because Error \u003e= Warn","time":"2022-02-17T10:54:54+01:00"}

	debugLogger := logger.New(logger.WithLevel(logger.LevelDebug))
	debugLogger.Debug("this logger will log anything as Debug is the lowest available level")
	debugLogger.Warn("and this will be logged too")
	// Output:
	// {"level":"debug","msg":"this logger will log anything as Debug is the lowest available level","time":"2022-02-17T10:54:54+01:00"}
	// {"level":"warning","msg":"and this will be logged too","time":"2022-02-17T10:54:54+01:00"}
}

Adapters

Gorm

To ensure that Gorm outputs logs in the correct format Gorm must be configured with a custom logger.

package main

import (
	gormLogger "github.com/coopnorge/go-logger/adapter/gorm"

	"gorm.io/driver/postgres"
	"gorm.io/gorm"
)

func main() {
	l, err := gormLogger.NewLogger(gormLogger.WithGlobalLogger())
	if err != nil {
		panic(err)
	}
	db, err := gorm.Open(sqlite.Open("test.db"), &gorm.Config{
		Logger: l,
	})
	if err != nil {
		panic(err)
	}
}

Datadog

To ensure that Datadog outputs logs in the correct format Datadog must be configured with a custom logger.

package main

import (
	"github.com/coopnorge/go-logger/adapter/datadog"

	"gopkg.in/DataDog/dd-trace-go.v1/ddtrace"
)

func main() {
	l, err := datadog.NewLogger(datadog.WithGlobalLogger())
	if err != nil {
		panic(err)
	}
	ddtrace.UseLogger(l)
}