cnfg

Hierarchical environment configuration for node.js applications

Installation

npm install cnfg

Basic configuration

Assuming configuration is stored somewhere under config directory which contains list of component specific configs:

config
|-- api.js
|-- app.js
`-- db.js

Each config file should export config object:

// config/db.js
module.exports = {
	host: 'localhost',
	name 'root'
}

// config/api.js
module.exports = {
	secret: 'many secrets'
}

Extracting config:

// cnfg requires absolute path to the base config directory
var path = __dirname + '/config';
var config = require('cnfg')(path);

// All below statements are true
config.db.host == 'localhost';
config.api.secret == 'many secrets';

Environment Configuration

It is often helpful to have different configuration values based on the environment the application is running in. For example, you may wish to use a different cache driver on your local development machine than on the production server. It is easy to accomplish this using environment based configuration.

Simply create a folder within the config directory that matches your environment name, such as development or testing. Next, create the configuration files you wish to override and specify the options for that environment.

Here is example structure of environment-based config:

config
|-- api.js
|-- app.js
|-- db.js
|-- index.js
`-- development
|   |-- api.js
|   `-- db.js
`-- test
|   |-- api.js
|   `-- db.js
`-- production
    |-- api.js
    `-- db.js

Imagine we use passworded db connection only in production env, but all other stuff (dbname, user, etc.) is the same we can deal with it in the next way:

Common db config:

// config/db.js
module.exports = {
	dbname: 'important_database',
	user: 'root'
}

production db config:

// config/production/db.js
module.exports = {
	password: '12345678'
}

Put config extractor to index.js in config folder for convenience

// config/index.js
// Put index js in config base directory and whe you require config dir
// it will return neat appropriate env config object
module.exports = require('cnfg')(__dirname);

Now use the config:

var config = require('./path/to/config');

// Assuming process.env.NODE_ENV is set to production
// config.db will be equal to:
{
	dbname: 'important_database',
	user: 'root',
	password: '12345678'
}

You don't need to specify all config values in env-specific config, because it inherits previous level config.

Specify environment

By default process.env.NODE_ENV value will be used as environment if it isn't set, then environment will be set to development.
Also it is possible to specify environment manually passing it as seconf arg to cnfg:

require('cnfg')(path_to_config, 'staging')

process.env overrides

You can override config using process.env using this naming convention:

CNFG_DB__HOST=db.example.com

It will set config.db.host value.

CNFG_DB__CONNECTION__MASTER__HOST=master.db.example.com

will set config.db.connection.master.host value.

CNFG_DB__CONNECTION_URI=localhost@localhost

will set config.db.connection_uri value.

License

The MIT License (MIT) Copyright (c) 2014 Egor Gumenyuk [email protected]

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.