appkit

README

App Kit

This repository provides a set of useful libraries that can be used to quickly build a Go applications.

go get github.com/nicklasfrahm-dev/appkit

Logging

This package provides a simple logging library based on zap, which may be configured at runtime using the environment variables shown below. The logger is optimized for structured logging using Loki as a log aggregation system. By default the logger will use a production-ready configuration, but it can be configured to output logs in a more human-readable format for development purposes.

Environment variable	Description	Default	Allowed values
LOG_LEVEL	The minimum log level to output.	info	debug, info, warn, error, fatal
LOG_FORMAT	The log format to use.	json	json, console

Example

package main

import (
	"context"
	"fmt"

	"github.com/nicklasfrahm-dev/appkit/logging"
	"go.uber.org/zap"
)

func main() {
	logger := logging.NewLogger()

	port := 8080

	// Don't do this.
	logger.Info(fmt.Sprintf("Starting HTTP server on port %d", port))
	logger.Sugar().Infof("Starting HTTP server on port %d", port)

	// Do this instead.
	logger.Info("Starting HTTP server", zap.Int("port", port))

	printLog(logger)

	// This is how you can use a context to pass a logger around.
	ctx := logging.WithLogger(context.Background(), logger)
	printLogWithContext(ctx)

	// This is how you can add fields to the logger in the context.
	printLogWithContext(logging.WithFields(ctx, zap.String("key", "value")))
}

// This is how you can pass the logger around.
func printLog(logger *zap.Logger) {
	logger.Info("This is a log message", zap.String("key", "value"))
}

// This is how you can use a context to pass the logger around.
func printLogWithContext(ctx context.Context) {
	logger := logging.FromContext(ctx)
	logger.Info("This is a log message", zap.String("key", "value"))
}

License

This project is and will always be licensed under the MIT License. See the LICENSE.md file for more information.