minconf

minconf is a minimal configuration library.

minconf loads an application's configuration based on the value of an environment variable, e.g. NODE_ENV. minconf supports merging of environment variables and command line arguments.

Configuration

Define environment configurations as objects or in files.

var configs = {
  $: {

    // defines merge order of object properties, files, command-line arguments and the environment
    envs: {
      development: 'common config.local.json ARGV ENV',
      test: 'common test ARGV ENV',
      production: 'common production ARGV ENV'
    }
  },

  common: {
    database: {
      user: 'superuser'
      password: 'password'
    }
  },

  test: {
    database: {
      password: 'secret'
    }
  },

  production = require('./config-production.json')
};

Configure minconf. In this example, the environment is chosen based on the value of NODE_ENV environment variable. If NODE_ENV is not set, it defaults to 'development'.

var config = MinConf.load(configs).config;

When running in development

config.database.user == 'superuser'
config.database.password == 'password'

When running in NODE_ENV=test

config.database.user == 'superuser'
config.database.password == 'secret'

Merging Precendence

Merging occurs left to right. In this example,

development: 'common config.local.json ARGV ENV'

The base opbject is common, then overriden by a file config.local.json, then overridden by ARGV, which are the command line arguments and then overriden by ENV, which are the process environment variables. In other words, environment variables override command line arguments which override a local configuration file which overrides the base object.

WARNING: Avoid merging environment variables. Environment variables can be affected by parent process or other init scripts.

Overriding Selector

To override the environment variable seletor and default enviroment, set options.envSelector and options.defaultEnv respectively

var configs = {
    $: {
      options: {
        envSelector: 'NODE_ENV',
        defaultEnv: 'development',
        wd: process.cwd()
      },

      envs: {
        ...
      }
    }
}

Running your app

Use any combination of config files, environment variables and command line arguments.

NODE_ENV=test node app.js --db.password='secret'

Use env command to use periods in environment variables. It is recommended to use command line arguments instead.

env 'db.user=foo' 'db.pass=secret' node app.js

License

The MIT License

Copyright (c) 2014 Mario Gutierrez [email protected]

See the file LICENSE for copying permissions.