✏️ Mogrus

A Go wrapper for Logrus, Errors and Mongo giving you extremely detailed log reports. This package is designed to be used with github.com/ainsleyclark/errors for error reporting with codes, messages and more.

Overview

✅ Add hooks to a Mongo collection.
✅ Logs with custom errors featuring codes, messages and lifelines.
✅ Customisable expiry times for different Logrus levels.
✅ Specify a callback function for when an entry is fired to Mongo.

Why?

Detailed and verbose logging is important to any application or API. This package aims to make it easy for APIs to log errors to a central location, using a Logrus Hook.

Installation

go get -u github.com/ainsleyclark/mogrus

How to use

Below is an example of how to use Mogrus, instantiate a Logrus instance and connect to a Mongo DB and pass the hook to the AddHook() function.

Add hook

func ExampleMogrus() {
	l := logrus.New()

	clientOptions := options.Client().
	ApplyURI(os.Getenv("MONGO_CONNECTION")).
	SetServerAPIOptions(options.ServerAPI(options.ServerAPIVersion1))

	client, err := mongo.Connect(context.Background(), clientOptions)
	if err != nil {
		log.Fatalln(err)
	}

	opts := mogrus.Options{
		Collection: client.Database("logs").Collection("col"),
		// FireHook is a hook function called just before an
		// entry is logged to Mongo.
		FireHook: func(e mogrus.Entry) {
			fmt.Printf("%+v\n", e)
		},
		// ExpirationLevels allows for the customisation of expiry
		// time for each Logrus level by default entries do not expire.
		ExpirationLevels: mogrus.ExpirationLevels{
			logrus.DebugLevel: time.Second * 5,
			logrus.InfoLevel:  time.Second * 15,
			logrus.ErrorLevel: time.Second * 30,
		},
	}

	// Create the new Mogrus hook, returns an error if the
	// collection is nil.
	hook, err := mogrus.New(context.Background(), opts)
	if err != nil {
		log.Fatalln(err)
	}

	// Add the hook to the Logrus instance.
	l.AddHook(hook)

	l.Debug("Debug level")
	l.WithField("key", "value").Info("Info level")
	l.WithError(errors.NewInternal(errors.New("error"), "message", "op")).Error("Error level")
}

Entry

The definition of an entry below is the object that is fired to Mongo.

// Entry defines a singular entry sent to Mongo
// when a Logrus event is fired.
Entry struct {
	Level   string               `json:"level" bson:"level"`
	Time    time.Time            `json:"time" bson:"time"`
	Message string               `json:"message" bson:"message"`
	Data    map[string]any       `json:"data" bson:"data"`
	Error   *Error               `json:"error" bson:"error"`
	Expiry  map[string]time.Time `json:"expiry" bson:"expiry"`
}

Error

The definition of an error below is the object that is stored in an Entry when log.WithError is used.

// Error defines a custom Error for log entries, detailing
// the file line, errors are returned as strings instead
// of the stdlib error.
Error struct {
	Code      string `json:"code" bson:"code"`
	Message   string `json:"message" bson:"message"`
	Operation string `json:"operation" bson:"op"`
	Err       string `json:"error" bson:"err"`
	FileLine  string `json:"file_line" bson:"file_line"`
}