good-env

good-env

🚨 v7 requires Node version 18.20.4 or higher! 🚨

good-env

A more intuitive way to work with environment variables in Node.js applications.

Why good-env?

When building non-trivial applications, working with environment variables as raw strings can be limiting. good-env provides:

• Type conversion (strings to numbers, booleans, lists, etc.)
• Default values
• Existence checking
• Validation
• No production dependencies

Installation

npm install good-env --save

Usage

Basic Usage

Import the package:

const env = require('good-env');

Getting Values

Simple Values

// Get a string (default behavior)
env.get('HOST');                    // 'localhost'

// With a default value if not set
env.get('NOT_SET', 'default');      // 'default'

Type Conversion

// Get as a number
env.getNumber('PORT');              // 8080 (as a number, not string)
env.num('PORT');                    // Shorthand for getNumber()

// Get as a boolean
env.getBool('DEBUG');               // true (converts 'true' string to boolean)
env.bool('DEBUG');                  // Shorthand for getBool()

// Get as a list
env.getList('ALLOWED_ORIGINS');     // ['localhost', 'example.com']
env.list('ALLOWED_ORIGINS');        // Shorthand for getList()

// Get a numeric list
env.list('VALUES', { cast: 'number' }); // [1, 2, 3] (converts from '1,2,3')

URLs and IPs

// Get as a URL object
env.getUrl('API_ENDPOINT');         // Returns URL object with helpful properties
env.url('API_ENDPOINT');            // Shorthand for getUrl()

// Get an IP address (with validation)
env.getIp('SERVER_IP', '127.0.0.1'); // Returns the IP if valid, or default

Multiple Variables

First Available Value

// Use first available variable from a list
env.get(['PRIMARY_HOST', 'BACKUP_HOST', 'DEFAULT_HOST']);

// With default fallback
env.get(['PRIMARY_HOST', 'BACKUP_HOST'], 'localhost');

Batch Operations

// Get multiple values as an array
env.getAll(['SECRET', 'HOST', 'PORT']);

// Get multiple values as an object with defaults
env.getAll({
  API_KEY: null,         // null means no default
  PORT: 3000,            // Default if not set
  DEBUG: false
});

Validation

Existence Checking

// Check if variables exist
env.ok('HOST');                     // true if HOST exists
env.ok('HOST', 'PORT', 'API_KEY');  // true if ALL exist

Assertions

// Validate variables (throws error if invalid)
env.assert(
  // Simple existence check
  'HOST',
  
  // Type checking
  { PORT: { type: 'number' }},
  
  // Custom validation
  { REFRESH_INTERVAL: { 
      type: 'number', 
      ok: val => val >= 1000 
    }
  }
);

Adding to the environment

env.set('NEW_ENV_VAR', 'newVal');
process.env.NEW_ENV_VAR // 'newVal'
env.get('NEW_ENV_VAR'); // 'newVal'

AWS Credentials

// Get AWS credentials from standard environment variables
const {
  awsKeyId,
  awsSecretAccessKey,
  awsSessionToken,
  awsRegion
} = env.getAWS();

// With default region
const credentials = env.getAWS({ region: 'us-west-2' });

AWS Secrets Manager Integration

Some folks like to store secrets in AWS secrets manager in the form of a JSON object as opposed (or in addition) to environment variables. It's me, I'm some folks. Good Env now supports this pattern. To avoid introducing a dependency you'll have to bring your own instance of AWS Secrets Manager though. Be sure to specify your AWS region as an environment variable, otherwise, it'll default to us-east-1.

Not only will your secrets be merged with the Good Env store, but they will also be stored in the underlying process.env object in case there are components that are still pulling from the environment directly.

Note, if something goes wrong, this function will throw an error.

const awsSecretsManager = require('@aws-sdk/client-secrets-manager');

(async function() {
  // Load secrets from AWS Secrets Manager
  await env.use(awsSecretsManager, 'my-secret-id');

  // The secret ID can also be specified via environment variables
  // AWS_SECRET_ID or SECRET_ID
  await env.use(awsSecretsManager);

  // Secrets are automatically merged with existing environment variables
  // and can be accessed using any of the standard methods
  const secretValue = env.get('someSecretFromAWSSecretsManager');
}());

Important Behavior Notes

Boolean Existence vs Value

When checking for the existence of a boolean environment variable:

// If A_BOOL_VAL=false
env.ok('A_BOOL_VAL');   // Returns true (checking existence, not value)
env.getBool('A_BOOL_VAL'); // Returns false (actual value)

URL Validation

• getUrl() only supports 'http', 'https', 'redis', and 'postgresql' protocols
• Invalid URLs return null instead of throwing errors
• Using getUrl() ensures proper URL format

Examples

Complete Configuration Setup

// app-config.js
const env = require('good-env');

// Validate critical variables
env.assert(
  'DATABASE_URL',
  { PORT: { type: 'number' }}
);

module.exports = {
  port: env.num('PORT', 3000),
  database: env.url('DATABASE_URL'),
  debug: env.bool('DEBUG', false),
  allowedOrigins: env.list('ALLOWED_ORIGINS', 'localhost'),
  cache: {
    enabled: env.bool('CACHE_ENABLED', true),
    ttl: env.num('CACHE_TTL', 3600)
  }
};

License

MIT