dslogger

dslogger

dslogger is a lightweight logger that uses zap for fast, structured logging and lumberjack for efficient log rotation.

Usage

Simple Console Logger

Use NewSimpleConsoleLogger to quickly create a console-only logger:

package main

import (
  "github.com/K4rian/dslogger"
)

func main() {
    // Create a console-only logger with default configuration at "info" level
    logger, err := dslogger.NewSimpleConsoleLogger("info")
    if err != nil {
        log.Fatalf("Error creating console logger: %v", err)
    }

    // Log an informational message
    logger.Info("This is an info message from the simple console logger!")
    logger.Warn("Unusual activity detected", "ip", "X.X.X.X")
    logger.Error("Error processing request", "requestID", "abc123")
}

Simple Logger (Console and File)

Use NewSimpleLogger to create a logger that writes to both the console and a file (using default configuration):

package main

import (
  "github.com/K4rian/dslogger"
)

func main() {
    // Create a logger that outputs to both console and file at "debug" level
    logger, err := dslogger.NewSimpleLogger("debug")
    if err != nil {
        log.Fatalf("Error creating logger: %v", err)
    }

    // Log messages at various levels
    logger.Debug("Debug message", "user", "james")
    logger.Info("Info message", "action", "login")
    logger.Warn("Warning message", "ip", "X.X.X.X")
    logger.Error("Error message", "error", "file not found", "file", "/opt/files/myfile.txt")
}

Service-Specific Logger

This example shows how to derive a service-specific logger from a base logger using the WithService method.
The derived logger automatically attaches a "service": "AuthService" field to every log entry, making it easier to distinguish logs for different services in your application (especially when using JSON file format for logs):

package main

import (
  "github.com/K4rian/dslogger"
)

func main() {
    // Create a console-only logger with default configuration at "info" level
    logger, err := dslogger.NewSimpleConsoleLogger("info")
    if err != nil {
        log.Fatalf("Error creating console logger: %v", err)
    }
	logger.Debug("You shouldn't be able to see this message")
	logger.Info("A simple info message from the base logger!")

    // Derive a logger for a specific service
    authLogger := logger.WithService("AuthService")

    // Logs will include the "service" field when using JSON file format
    authLogger.Info("Authentication successful", "user", "james")
}

Advanced Console-Only Logger

This example demonstrates how to create an advanced console-only logger with a custom configuration and options.
It customizes the encoder settings and sets a custom service name using a functional option:

package main

import (
  "github.com/K4rian/dslogger"
)

func main() {
    // Define a custom configuration for console logging
    customConfig := &dslogger.Config{
        Level:                 "debug",
        ConsoleConfig:         dslogger.DefaultConsoleEncoderConfig,
        FieldSeparator:        ": ",
        ConsoleSeparator:      " | ",
        ServiceNameDecorators: [2]string{"[", "]"},
    }

    // Create a console-only logger with custom configuration and a functional option to set the service name
	logger, err := NewConsoleLogger("debug", customConfig, dslogger.WithServiceName("MyService"), dslogger.WithCallerSkip(1))
	if err != nil {
		log.Fatalf("Failed to create advanced console logger: %v", err)
	}

    logger.Info("This is a custom advanced console-only logger", "count", 14)
}

Advanced Logger (Console and File)

Create an advanced logger with custom configuration and options that writes to both console and file.
This example shows how to configure the file output format (JSON or Text) by setting the LogFileFormat and corresponding encoder configuration:

package main

import (
  "github.com/K4rian/dslogger"
)

func main() {
    // Define a custom configuration for the full logger
	customConfig := &dslogger.Config{
		LogFile:               "./full.log",
		LogFileFormat:         dslogger.LogFormatJSON, // Either LogFormatJSON or LogFormatText
		MaxSize:               50,
		MaxBackups:            7,
		MaxAge:                60,
		Compress:              true,
		Level:                 "debug",
		ConsoleConfig:         dslogger.DefaultConsoleEncoderConfig,
		FileConfig:            dslogger.DefaultJSONEncoderConfig, // For JSON output, use DefaultJSONEncoderConfig; for text, use DefaultTextEncoderConfig
		FieldSeparator:        "=",
		ConsoleSeparator:      "    ",
		ServiceNameDecorators: [2]string{"(", ")"},
	}

	// Create a logger that writes to both console and file, with a custom "branch" and "creation_time" fields
	logger, err := NewLogger("debug", customConfig, WithCustomFields("branch", "dev", "creation_time", time.Now()))
    if err != nil {
        log.Fatalf("Failed to create full logger: %v", err)
    }

    // Log messages at various levels.
    logger.Debug("Debug message with full logger", "user", "bob")
    logger.Info("Info message with full logger", "operation", "data_import")
    logger.Warn("Warning message", "warning", "low disk space")
    logger.Error("Error message", "error", "failed to connect to database")
}

Installation

To install dslogger, simply run the following command:

go get github.com/k4rian/dslogger

For Go modules (if you're using Go 1.11+), ensure that your project is using modules and run:

go get github.com/k4rian/dslogger@latest

License

MIT