rc

The non-configurable configuration loader for lazy people.

Usage

The only option is to pass rc the name of your app, and your default configuration.

var conf = require('rc')(appname, {
  //defaults go here.
  port: 2468,

  //defaults which are objects will be merged, not replaced
  views: {
    engine: 'jade'
  }
});

rc will return your configuration options merged with the defaults you specify. If you pass in a predefined defaults object, it will be mutated:

var conf = {};
require('rc')(appname, conf);

Standards

Given your application name (appname), rc will look in all the obvious places for configuration.

• command line arguments (parsed by minimist)
• environment variables prefixed with ${appname}_
• if you passed an option --config file then from that file
• a local .${appname}rc or the first found looking in ./ ../ ../../ ../../../ etc.
• $HOME/.${appname}rc
• $HOME/.${appname}/config
• $HOME/.config/${appname}
• $HOME/.config/${appname}/config
• /etc/${appname}rc
• /etc/${appname}/config
• the defaults object you passed in.

All configuration sources that were found will be flattened into one object, so that sources earlier in this list override later ones.

Configuration File Formats

Configuration files (e.g. .appnamerc) may be in either json or ini format. The example configurations below are equivalent:

Formatted as ini

; You can include comments in `ini` format if you want.

dependsOn=0.10.0


; `rc` has built-in support for ini sections, see?

[commands]
  www     = ./commands/www
  console = ./commands/repl


; You can even do nested sections

[generators.options]
  engine  = ejs

[generators.modules]
  new     = generate-new
  engine  = generate-backend

Formatted as json

{
  "dependsOn": "0.10.0",
  "commands": {
    "www": "./commands/www",
    "console": "./commands/repl"
  },
  "generators": {
    "options": {
      "engine": "ejs"
    },
    "modules": {
      "new": "generate-new",
      "backend": "generate-backend"
    }
  }
}

Since ini, and env variables do not have a standard for types, your application needs be prepared for strings.

Advanced Usage

Pass in your own argv

You may pass in your own argv as the third argument to rc. This is in case you want to use your own command-line opts parser.

require('rc')(appname, defaults, customArgvParser);

Note on Performance

rc is running fs.statSync-- so make sure you don't use it in a hot code path (e.g. a request handler)

License

BSD / MIT / Apache2