node-user-config v0.1.0

node-user-config

Read application settings from a configuration file with an environment variable fallback.

Why?

I needed a simple way to specify some application configuration without it being checked in to source control. Without file system access to the deployment server, environment variables are the best option for application variables whereas a simple user.config.json file is easier to deal with at development time.

Install

npm install node-user-config

How it works

This module will import a simple json file and act as a wrapper around that file. If the file does not exist, an environment variable with a similar name will be returned instead.

Rules

The default naming scheme for environment variables uses the following rules: Given the following property name to lookup: somePropertyName

• A property inside user.config.json names somePropertyName will be returned if found.
• An environment variable named SOME_PROPERTY_NAME will be returned if not.

• If no environment varialbe named SOME_PROPERTY_NAME exists, null will be returned.

Overrides

If a second argument is specified to the get method, the name of the environment variable can be overidden.

Exmaple

const mongoUrl = config.get('mongoUrl', 'MY_APPS_DATABSAE_URL');  

This will search the user.config.json file for the mongoUrl property but fallback to an environment variable named MY_APPS_DATABSAE_URL if not found.

Error

If the third parameter passed to the get method is true, if no key has been found in the user.config.json file or in the fallback environment variable; an error will be thrown.

Usage

user.config.json

{
  "mongoUrl": "mongodb://localhost/TestApp"
}

index.js

const config = require('node-user-config');

// Will return mongoUrl property from user.config.json if the file exists 
//   or will search for an environment variable named MONGO_URL if not.
const mongoUrl = config.get('mongoUrl');