config-discovery

What is it?

A simple JSON configuration loading utility.

What does it allow you to do ?

• Look for a configuration file from a list of possible locations, and load the first one.
• Create a composite configuration using patches from another config file or from the environment.

What makes it different from other config libraries?

• It allows you to compose your configuration from different sources in one block of code.
• It does not need any setups with any predefined directories. You're free.
• Though environment JSON prototyping exists on other libraries, config-discovery gives you the freedom on how to organize your prototypes.

Why did you make this ?

This utility was built with containerizing backend NodeJS applications in mind. Configuration setups in containers almost always involve the use of K8s ConfigMaps and Secrets, which are mounted either as a file and/or as environment variables, config-discovery takes care of locating and compositing these configurations into a single json object for you.

Whats new in 0.1.0?

• Stream lined interface for both patching, and find first method names.
• Added support for Environment and JSON objects in for* and or* method families.
• Added support for JSON objects in patching methods.
• Removed tests from npm package, make it smaller.

Sample usage

Scenario 1: Just want to load a debug config.

let Config = require('config-discovery');

...

let debugValues = {user: 'DebugDB', password: 'password'};

let configuration = new Config()
    .fromFile('/other/env/directory/config.json')
    .orObject(debugValues)
    .get();

////// OR

let prototype = {user: 'DB_USERNAME', password: 'DB_PASSWORD'}
let configuration = new Config()
    .fromFile('/other/env/directory/config.json')
    .orEnv(prototype)
    .get();

////// OR

let debugConfig = '/local/conf/myconfig.json'

let configuration = new Config()
    .fromFile('/other/env/directory/config.json')
    .orFile(debugConfig)
    .get();

const knex = Knex(configuration)

Scenario 2: Simply load a config outside the application.

let Config = require('config-discovery');

...

let configuration = new Config()
    .fromFile('/configs/config.json')
    .get();

const knex = Knex(configuration)

Scenario 3: Prioritize a configuration based on location.

This will load the first configuration it finds, starting from fromFile().

let Config = require('config-discovery');

...

let configuration = new Config()
    .fromFile('/configs/config.json')
    .orFile('/configuration/config.json')
    .orFile('/etc/my_configs/config.json')
    .get();

const knex = Knex(configuration)

Scenario 4: Compositing a configuration.

This happens when sensitive data are provided with K8S Secrets, which can be mounted as a set of environment variables. Wrangle them into a JSON with a prototype!

let Config = require('config-discovery');

...

let envPrototype = {connection: {user: 'SECRET_DB_USERNAME', password: 'SECRET_DB_PASSWORD'}};

let configuration = new Config()
    .fromFile('/configs/config.json')
    .orFile('/configuration/config.json')
    .orFile('/etc/my_configs/config.json')
    .thenPatchWith()
    .env(prototype)
    .get();

const knex = Knex(configuration)

Or simply patch with another file.

let Config = require('config-discovery');

...


let configuration = new Config()
    .fromFile('/configs/config.json')
    .orFile('/configuration/config.json')
    .orFile('/etc/my_configs/config.json')
    .thenPatchWith()
    .configFile('/var/secrets.json')
    .get();

const knex = Knex(configuration)