@medolino/node-config

@medolino/node-config is a helper tool that deals with env configuration in an organized way.

How It Works

When calling initialization function, user provides a configuration parameter settings, which are used to validate, cast and organize parsed process.env values in a tree structure. After initialization getConfig helper function is exposed and can be used to retrieve specific configuration value or set of values.

As detenv is used under the hood, environment variables can also be stored in a .env file.

Install

Install locally using npm:

npm i @medolino/node-config --save

Usage

Create a .env file in the root of your project and store desired env variables:

API_HOST = 0.0.0.0
API_PORT = 3000
DB_HOST = 0.0.0.0
DB_PORT = 27018
LOGGER_LEVEL = debug

Initialize config and use getConfig function to get specific config values:

const nodeConfig = require('@medolino/node-config')

const paramConfig = {
  api: {
    server: {
      host: {
        envVarName: 'API_HOST', // env variable name
        type: nodeConfig.valueDataTypes.STRING, // data type to cast to
        required: false, // is env value required
        defaultValue: 'localhost' // use this value, when env value not provided
      },
      port: {
        envVarName: 'API_PORT',
        type: nodeConfig.valueDataTypes.INTEGER,
        required: false,
        defaultValue: 4000
      }
    },
    db: {
      host: {
        envVarName: 'DB_HOST',
        type: nodeConfig.valueDataTypes.STRING,
        required: false,
        defaultValue: 'localhost'
      },
      port: {
        envVarName: 'DB_PORT',
        type: nodeConfig.valueDataTypes.INTEGER,
        required: false,
        defaultValue: 27017
      }
    },
    logger: {
      level: {
        envVarName: 'LOGGER_LEVEL',
        type: nodeConfig.valueDataTypes.STRING,
        required: true,
        defaultValue: 'info',
        enum: ['debug', 'info', 'fatal']
      }
    }
  }
}

const { getConfig } = nodeConfig({ paramConfig })

const apiConfig = getConfig('api')

console.log(apiConfig)

/*
{
  "server": {
    "host": "0.0.0.0",
    "port": 3000
  },
  "db": {
    "host": "0.0.0.0",
    "port": 27017
  },
  "logger": {
    "level": "debug"
  }
}
*/

const dbConfig = getConfig('api.db')
console.log(dbConfig)

/*
{
  "host": "0.0.0.0",
  "port": 27017
}
*/

const loggerEnabled = getConfig('api.logger.level')
console.log(loggerEnabled)

/*
"debug"
*/

Overriding values from .env

You can override any env value, defined in .env using a parameter on the CLI command line when starting the application:

LOGGER_LEVEL=fatal npm run start

Supported value data types

During initialization, env values are casted to desired data type.

A list of supported data types:

• boolean,
• integer,
• string,
• array of strings,
• array of integers

See: nodeConfig.valueDataTypes

Documentation

• API Documentation