config

What is config?

The config npm package is designed to simplify the management of configuration settings for Node.js applications. It allows developers to organize configuration variables for different deployment environments, such as development, testing, and production, in a structured and accessible manner. This package supports configuration file formats like JSON, YAML, and JavaScript, enabling easy integration into various projects.

What are config's main functionalities?

Environment-Specific Configurations

This feature allows you to load different configurations based on the current environment (e.g., development, production). The code sample demonstrates how to access a database configuration specific to the current environment.

const config = require('config');
let dbConfig = config.get('Customer.dbConfig');
console.log(dbConfig.host);

Custom Environment Variables

Leverage custom environment variables within your configuration files. The example shows how to access a nested configuration property, such as a database password.

const config = require('config');
let dbPassword = config.get('Customer.dbConfig.password');
console.log(dbPassword);

Configuration File Formats

Supports multiple configuration file formats including JSON, YAML, and JavaScript. This example demonstrates accessing a server port setting from a JSON configuration file.

// Assuming you have a JSON config file named 'default.json' in your config directory
const config = require('config');
let serverPort = config.get('server.port');
console.log(serverPort);

Other packages similar to config

dotenv

Dotenv is a module that loads environment variables from a .env file into process.env. While dotenv is focused on loading environment variables, config deals with organizing and accessing hierarchical configurations.

nconf

nconf is a hierarchical node.js configuration with files, environment variables, command-line arguments, and atomic object merging. It provides a similar functionality to config but with a different approach to organizing and prioritizing configuration sources.

README

Configure your Node.js Applications

      release notes

Introduction

Node-config organizes hierarchical configurations for your app deployments.

It lets you define a set of default parameters, and extend them for different deployment environments (development, qa, staging, production, etc.).

Configurations are stored in configuration files within your application, and can be overridden and extended by environment variables, command line parameters, or external sources.

This gives your application a consistent configuration interface shared among a growing list of npm modules also using node-config.

Project Guidelines

• Simple - Get started fast
• Powerful - For multi-node enterprise deployment
• Flexible - Supporting multiple config file formats
• Lightweight - Small file and memory footprint
• Predictable - Well tested foundation for module and app developers

Quick Start

The following examples are in JSON format, but configurations can be in other file formats.

Install in your app directory, and edit the default config file.

$ npm install config
$ mkdir config
$ vi config/default.json

{
  // Customer module configs
  "Customer": {
    "dbConfig": {
      "host": "localhost",
      "port": 5984,
      "dbName": "customers"
    },
    "credit": {
      "initialLimit": 100,
      // Set low for development
      "initialDays": 1
    }
  }
}

Edit config overrides for production deployment:

 $ vi config/production.json

{
  "Customer": {
    "dbConfig": {
      "host": "prod-db-server"
    },
    "credit": {
      "initialDays": 30
    }
  }
}

Use configs in your code:

const config = require('config');
//...
const dbConfig = config.get('Customer.dbConfig');
db.connect(dbConfig, ...);

if (config.has('optionalFeature.detail')) {
  const detail = config.get('optionalFeature.detail');
  //...
}

config.get() will throw an exception for undefined keys to help catch typos and missing values. Use config.has() to test if a configuration value is defined.

Start your app server:

$ export NODE_ENV=production
$ node my-app.js

Running in this configuration, the port and dbName elements of dbConfig will come from the default.json file, and the host element will come from the production.json override file.

Articles

• Configuration Files
  • Special features for JavaScript configuration files
• Common Usage
• Environment Variables
• Reserved Words
• Command Line Overrides
• Multiple Node Instances
• Sub-Module Configuration
• Configuring from a DB / External Source
• Securing Production Config Files
• External Configuration Management Tools
• Examining Configuration Sources
• Using Config Utilities
• Upgrading from Config 0.x
• Webpack usage

Further Information

If you still don't see what you are looking for, here are some more resources to check:

• The wiki may have more pages which are not directly linked from here.
• Review questions tagged with node-config on StackExchange. These are monitored by node-config contributors.
• Search the issue tracker. Hundreds of issues have already been discussed and resolved there.

Contributors

lorenwest	markstos	iMoses	elliotttf	jfelege	leachiM2k
josx	enyo	leosuncin	arthanzel	eheikes	th507
Osterjour	cunneen	nsabovic	BadgerBadgerBadgerBadger	simon-scherzinger	leonardovillela
axelhzf	benkroeger	fgheorghe	IvanVergiliev	jpwilliams	jaylynch
jberrisch	kgoerlitz	bertho-zero	NguyenMatthieu	nitzan-shaked	robertrossmann

License

May be freely distributed under the MIT license.

Copyright (c) 2010-2022 Loren West and other contributors