habitat

habitat

Library for managing your environment vars.

Why

According to factor 3, you should be storing your configuration as environment variables. Writing process.env everywhere can be real annoying, so this abstracts away of that manipulation. It also provides some nice little nicities for testing.

Installation

Why NPM of course!

$ npm install habitat

Usage

new habitat([prefix, [defaults]])

Creates a new environment manipulator.

prefix is the prefix for your environment variables. For example, if your app is called airsupport, it's probably good to namespace your environment variables like so:

export AIRSUPPORT_HOST=lolcathost
export AIRSUPPORT_PORT=3000
export AIRSUPPORT_WEBSOCKETS=true

In this case, your prefix will 'airsupport' -- prefixes will be auto-capitalized because only barbarians use lowercase letters in their environment variables.

Note that you don't have to pass in a prefix, if you're crazy like that. Keys will be looked up (after capitalization) straight from the env:

var env = new habitat;
var path= env.get('path'); 

defaults is an object representing the defaults if a key cannot be found in the environment. This should be used sparingly.

var env = new habitat('airsupport', { port: 3000 })
// will try the environment first, then fall back to 3000
var port = env.get('port');

habitat#get(key)

Gets a key from the environment. Automatically prefixes with the prefix passed to the constructor, if necessary.

habitat#get will also try to do some parsing of the value if it looks like a boolean, number or json, so you can do things like this:

exports APP_ADMINS='["[e-mail]", "[e-mail]"]';

var env = habitat('app');
var admins = env.get('admins');
console.log(admins.indexOf('[e-mail]')) // 1

habitat#set(key, value)

Sets an environment variable, with prefix if passed.

habitat#unset(key)

Unsets an environment variable

habitat#temp(object, callback)

Temporarily overrides environment variables with values from object.

callback can be syncronous if defined without any parameters, or async if defined with a single parameter.

Example:

var env = new habitat('airsupport', {
  protocol: 'http',
  host: 'airsupport.io',
  port: 3000
});

// sync 
var tempEnv = {
  host: 'lolcathost'
  port: 5000
};

env.temp(tempEnv, function() {
  console.log(env.get('host')) // "lolcathost"
  console.log(process.env['AIRSUPPORT_HOST']) // "lolcathost"
})

console.log(env.get('host')) // "airsupport.io"

// async
env.temp({tempEnv, function(done)
  process.nextTick(function(){
    console.log(env.get('port')) // 5000
    done();
  });
})

License

MIT