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)
}