logger.org.md

Logging

Overview

Logging allows you to provide transparency in your application. If you want to learn more about the processing and details of your application parts, logging is a good way. Supercharge provides a solid logger using the Winston logging library.

The logging utility coming with Supercharge is configurable to make it seamless for you to log to different destinations, like the console or a log file.

Configuraiton

The configuration file for the logger is located at config/logging.js containing the default log driver and channels. You can configure each log channel to your own needs.

The default log driver is console printing everything to your terminal. When using the file driver, you may adjust the log file name which defaults to app.log and is located in storage/logs/app.log

Available Drivers

Supercharge uses a driver-based approach for logging. A driver represents a single channel or multiple channels. A channel itself describes the destiation for log messages. Here’s a list of available logging drivers and the related log channels:

Channel Driver	Description
stacked	Logging to all available channels: console and file
console	Logging all messages to the terminal
file	Logging all messages to a dedicated log file

At this point, you can’t configure the stacked logger to exclude a specific channel. It will log to all available channels. This is very likely to change in future releases.

Using the Logger

The logging utility is part of the Supercharge framework. It provides methods for seven different log levels:

const Logger = require('@supercharge/framework/logging')

Logger.error(message)
Logger.warn(message)
Logger.info(message)
Logger.verbose(message)
Logger.debug(message)
Logger.silly(message)

The logger provides a method corresponding to the supported log levels.

Logging Context Data

Use the logger anywhere in your application. Supercharge ensures to initialize the logger when starting your application. For example, you may log an info message in your routes. Add context information like an ID with the help of template strings:

const Post = require('../models/post')
const Logger = require('@supercharge/framework/logging')

module.exports = {
  method: 'GET',
  path: '/post/{id}',
  handler: (request, h) => {
    const id = request.params.id

    Logger.info(`Showing blog post with ID: ${id}`)

    return h.view('blog/post', {
      post: await Post.findById(id)
    })
}

You may also pass context data to the log message using the sprintf syntax. Both channels, console and file, support the sprintf syntax format for all log levels. Here’s an example of a debug message containing the details about incoming request parameters:

Logger.debug(`Showing blog post with params: %j`, request.params)