Alepha Logger

A simple logger for Alepha applications

Installation

This package is part of the Alepha framework and can be installed via the all-in-one package:

npm install alepha

Alternatively, you can install it individually:

npm install @alepha/core @alepha/logger

Module

Minimalist logger module for Alepha.

It offers a global logger interface (info, warn, ...) via the $logger descriptor.

import { $logger } from "@alepha/logger";

class App {
  log = $logger();
}

Formatting and Destinations

AlephaLogger is extensible, destinations and formatters can be added or replaced.

Default log destinations are:

• ConsoleDestinationProvider: logs to the console.
• MemoryDestinationProvider: stores logs in memory for later retrieval.

Default log formatters are:

• JsonFormatterProvider: formats logs as JSON.
• SimpleFormatterProvider: formats logs as simple text (with colors when possible).
• RawFormatterProvider: formats logs as raw text without any formatting.

Log Level

You can configure the log level and format via environment variables:

• LOG_LEVEL: Sets the default log level for the application.
• LOG_FORMAT: Sets the default log format for the application.

LOG_LEVEL=debug LOG_FORMAT=json node src/index.ts

Log level is also available in the state as logLevel, which can be used to dynamically change the log level at runtime.

alepha.state("logLevel", "debug");

Log level is $module aware, meaning you can set different log levels for different modules. For example, you can set LOG_LEVEL=my.module.name:debug,info to set the log level to debug for my.module.name and info for all other modules.

API Reference

Descriptors

$logger()

Create a logger.

name is optional, by default it will use the name of the service.

import { $logger } from "@alepha/core";

class MyService {
  log = $logger();

  constructor() {
    this.log.info("Service initialized");
    // print something like '[23:45:53.326] INFO <app.MyService>: Service initialized'
  }
}