Description

Ultra lightweight configuration engine for node.js

Allows you to have a common configuration file with an ability to override particular settings in host-specific configuratin files.

How it works

For example, certain settings, like name of your application, do not depend on the type of the environment (be it production, dev or CI), and they never, or rarily change:

That'd be a name of your company, for example:

//conf/common.js:
    exports.conf = {
       name: 'My Super Awesome Kick Ass Startup'
    }

But the database connection string on the other hand is a totally different beast: Your Continuous Integration server connects to a dedicated DB:

//conf/ci-hostname.js:
    exports.conf = {
        db_connection: 'db.mongo-db.local'
    }

while a developer's machine runs a local DB server:

//conf/my-dev.js:
    exports.conf = {
        db_connection: 'localhost'
    }

And your awesome production server, the one that actually brings home bacon, uses something completely different:

//conf/linode.beefed-up.server.com.js:
    exports.conf = {
        db_connection: 'nosql-super-clustered-cloud-database'
    }

So if you want to overwrite a certain setting on a production server with hostname 'linode.beefed-up.server.com', you simply create a corresponding file in the 'conf' directory.

Node-config will load common configuration values and then override them with appropriate values from host-specific config file.

Example

Loading of configuration is as simple as this:

// Presuming that node-config sits under ./external folder in the project
require.paths.unshift('./external');

var conf = require('node-config'),
    sys = require('sys');

conf.initConfig(
    function(err) {
        if(err) {
            sys.log('Unable to init the config: ' + err); 
            return;
        }

        // Config loaded, can do those things now:

        console.log(conf.db_connection);
    }
);

For testing purposes you can override your hostname by supplying second argument to initConfig() function, just like that:

conf.initConfig(
    function(err) { // your normal stuff goes here... },
    'redefined-host-name'
);

which will force node-config to load conf/redefined-host-name.js instead of your host-specific config.

Setup

You need to have a conf directory in your project root folder (where your main .js file sits), and it has to containcommon.js file with following format:

exports.conf = {
    name: 'value',
    // ...
    name_m: 'value M'
};

If you wish to add host-specific config files, execute hostname from command line to find out what your hostname is and name your config file accordingly.

Please see node-config/conf/* and node-config/test.js for examples.

Thanks!

License

The MIT License

Copyright (c) 2010 by Artem Skvira

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.