Opinionated configuration for Node projects

We have a few Node based projects at Globality. Those Node projects have some configuration that is being loaded from ENV variables and some loading from credstash (secrets).

The purpose of this global configuration layer is to have a way to load the configuration dynamically from the ENV variables and only load secrets if we need them.

For example, in local dev we don't want any secrets to load from credstash because we don't want to have the AWS secrets floating around and complicating dev environments.

Also, right now the configuration layer is too verbose, this introduces a bit of magic like we have in microcosm, our python library

Basics

For the configuration layer to work, you need the NAME env var present. The library will warn you if you don't have it defined.

The module will look for all the env variables prefixed with the app name and compile a list out of all of them, if you require secrets, it will get merged.

Before

  YOURAPPNAME__GROUP__VAR: 'X',
  YOURAPPNAME__VAR: 'Y',
  YOURAPPNAME__BOOL_VAR_FALSE: false,
  YOURAPPNAME__BOOL_VAR_TRUE: true,
  YOURAPPNAME__BOOL_VAR_FALSE_LITERAL: false,
  YOURAPPNAME__BOOL_VAR_TRUE_LITERAL: true,
  YOURAPPNAME__BOOL_VAR_FALSE_LITERAL_D: false,
  YOURAPPNAME__BOOL_VAR_TRUE_LITERAL_D: true,
  SECRET_VAR: 'SECRET_VALUE' // automatically loads from credstash if required

After

{ 
  group: { 
    var: 'X'  
  },
  var: 'Y',
  boolVarFalse: false,
  boolVarTrue: true,
  boolVarFalseLiteral: false,
  boolVarTrueLiteral: true,
  boolVarFalseLiteralD:
  false,
  boolVarTrueLiteralD:
  true,
  secretVar: 'SECRET_VALUE'
}

Usage

Config

The module has 2 configuration options

1. secretLoaderPrefix Defaults to MICROCOSM

secretLoaderPrefix is used in order to get the version and the env to look for in credstash. (see secretLoader).

Say your secretLoaderPrefix is MICROCOSM, it will look for the env and version in the env vars using this code

  const version = process.env[`${this.secretLoaderPrefix}_CONFIG_VERSION`];
  const env = process.env[`${this.secretLoaderPrefix}_ENV`];

Note: The code above is internal implementation, you don't need it in your app.

2. parseBooleans Defaults to true

Env vars are string by default, if you want the JS object to have the native boolean value, you pass true in this var.

This will make 1, 0, true, True, false and False to "translate" to booleans. If this is false, you will get the string values and need to handle it in your application

Load configuration

import { makeConfig, Loader } from "nodule-config";

const loader = new Loader() // pass config as vars here if you need to

loader.toCombinedObject().then((configVars) => {
  const config = makeConfig(vars);

  // Do what you want with your configuratin
})