enco

Introduction

A node.js package for most simple config data loading based on app environment from YAML, CSON or JSON file(s).

This method for loading configs I use now for few years and I think it's time to create some united package.

So there it is.

Goals

To load config object from files or folder almost withnout configuration. Of course with environments inheritance.

Instalation

npm install enco

Examples

Single file config

At first we need to create YAML config file

production:
    host: #{process.env.HOST}
    port: #{process.env.PORT}

development:
    port: 8080
    
localhost:
    host: '127.0.0.1'
    port: #{process.env.PORT || 3000}

Then you can create .env file with ENV variables

PORT=80
HOST="10.0.0.1"

Load without config definition

In this case default configuration is the last one. So localhost.

var configLoader = require('enco');
var config = configLoader();

result:

{
    host: '127.0.0.1'
    port: 8080
}

Change environment with ENV variable

Default ENV variable name is NODE_ENV

// index.js
var configLoader = require('enco');
var config = configLoader();

run command:

NODE_ENV=development node index.js

result:

{
    host: '127.0.0.1'
    port: 8080
}

Change ENV variable name

You can change ENV variable name in config via parameter envName

// index.js
var configLoader = require('enco');
var config = configLoader({
    envName: 'ENVIRONMENT'
});

run command:

ENVIRONMENT=production node index.js

result:

{
    host: '10.0.0.1'
    port: 80
}

Multiple environments config file

At first we need to create few files

// config/config.production.json
{
    "host": "10.0.0.1",
    "port": "80"
}

// config/config.development.json
{
    "port": "8080"
}

// config/config.localhost.json
{
    "host": "127.0.0.1"
}

// index.js
var configLoader = require('enco');
var config = configLoader({
    type: 'json',
    dir: './config',
    isFolderStructure: true
});

run command:

node index.js

result:

{
    host: '127.0.0.1'
    port: 8080
}

Own environments

Default environments is production, test, development, localhost. But you can define your own:

var configLoader = require('enco');
var config = configLoader({
    environments: [
            'prod',
            'stage',
            'dev'
        ]
});

In this case default environment will be dev because it's last one.

Dependencies works like waterfall. If you select stage, it will inherit everything from prod config and rewrite or append its own values.

Variables injecting

Sometimes you need to pass some data to config and load then directly in it. For example, when you load environment variables some other way then through ENV vars (some json loaded to container in build etc.).

For this king of situations you can use inject option in configLoader config.

For example:

var configLoader = require('enco');

var injectedVars = {
    server: {
        port: 80
    },
    databases: {
        mysql: {
            host: 'some.mysql.con.string'
        }
    }
};

var config = configLoader({
    inject: injectedVars
});

After that you can load this variables in config via #{...} syntax like that:

production:
    port: #{server.port}
    mysql: #{databases.mysql.host}

development:
    port: 8080

localhost:
    port: 3000

Config API

There is a list of configuration options for config loading

Property	Description	Value	Default
type	Type of config files	cson or json	yaml
envName	Witch ENV variable define environments name. It works only if property environment is not set	string	NODE_ENV
environment	For defining current environment name your own way	string	Last value of environments property
environments	Array of all app environments with waterfall inheritance	string array	[ 'production', 'test', 'development', 'localhost' ]
isFolderStructure	Define if configs are in multiple files	bool	false
dir	Path to folder with configs	string	Starting point of app (process.cwd())
file	Define specific file what you want load, ignoring other options	string	null
filePrefix	If your config file name is not starting with config (config.cson or config.production.cson). You cant change it here.	string	config
envFilePath	If you have .env file on different path with different name	string	null
inject	You can inject variables for loading them via #{...} in config	object	`{}