lean-config v2.0.0

Leaner Config

Compact, flexible and least opinionated config loader.

• config parameters are stored in the files (.js and/or .json), not in one - they are scattered across many;
• so you can isolate task specific parameters in different files: i.e. app.js, mongodb.json, stripe.js and so forth;
• the files lying in the root of the config/ folder contains "general" parameters;
• the files placed under sub-folders contains some redefined parameters specific for distinct activity;
• specific sub-folder to load can be set via NODE_ENV variable, by the config load function parameter or it can be explicitly disabled;
• first, the general configs are being loaded, second the specific configs loaded and overrides the general;
• multiple environments like "production,new-york-servers" can be set;
• finally everything is being combined into one pure javascript object;
• 70 LoC, no dependencies.

Quick start

Do NOT use npm - otherwise you have to configurate configuration rig, that's awkward. Instead just download config/index.js into your config folder. You can ever include something like this:

  "scripts": {
    "postinstall": "wget -P config/ https://raw.github.com/googgah/lean-config/master/config/index.js"
  }, ...

into your package.json to automatically download it after npm install ...

Usage

Load only general configs (assuming NODE_ENV is not set):

    const config = require( './config' );
    //  ...
    app.listen( config.port, '0.0.0.0', () => {
        console.log( ` • API: ${config.name} (v${config.version})` );
        //  ...
    } );

Explicitly load general config (ignoring NODE_ENV):

    const config = require( './config' ).load( false );

Explicitly load specific config (ignoring NODE_ENV):

    const config = require( './config' ).load( 'qa' );

Load particular configs set via NODE_ENV:

    //  justta
    const config = require( './config' );
    //  ...

When last code is invoked like $ NODE_ENV=production node server.js, it uses 'production' configs.

Multiple environments can be set as a list separated by commas $ NODE_ENV=production,london-db node server.js Here, general configs are loaded, followed by the configs in production/ sub-folder and finally the configs from db-london/ sub-folder.

Combining

By default only objects are combined, arrays and simple entities are being overridden. This behaviour can be redefined via special property _combine. It's often convenient to merge arrays instead of replace. For example when you have somewhere in the general configs:

module.exports = {
...
  emails: [
    'alex@somehost.net',
    'ann@somehost.net'
  ],
};

and in the dev-team sub-folder

module.exports = {
...
  emails: [
    'josh@somehost.net',
    'helen@somehost.net',
    'nathan@somehost.net'
  ],
  _combine: {
    emails: true
  }
};

Resulting emails parameter will be merged to

module.exports = {
...
  emails: [
    'alex@somehost.net',
    'ann@somehost.net',
    'josh@somehost.net',
    'helen@somehost.net',
    'nathan@somehost.net'
  ],
};

instead of just to be overridden by the dev-team specialization.

Examples

Look into test folder