env-schema

Utility to check environment variables using JSON schema, Ajv and dotenv.

Install

npm install --save env-schema

Usage

const envSchema = require('env-schema')

const schema = {
  type: 'object',
  required: [ 'PORT' ],
  properties: {
    PORT: {
      type: 'string',
      default: 3000
    }
  }
}

const config = envSchema({
  schema: schema,
  data: data // optional, default: process.env
  dotenv: true // load .env if it's there, default: false
})

console.log(config)
// output: { PORT: 3000 }

It is possible to also use fluent-schema:

const envSchema = require('env-schema')
const S = require('fluent-schema')

const config = envSchema({
  schema: S.object().prop('port', S.string().default('3000').required()),
  data: data, // optional, default: process.env
  dotenv: true, // load .env if it's there, default: false
  expandEnv: true, // use dotenv-expand, default: false
})

console.log(config)
// output: { PORT: 3000 }

NB: support for additional properties in the schema is disabled for this plugin, with the additionalProperties flag set to false internally.

Custom keywords

This library supports the following Ajv custom keywords:

separator

Type: string

Applies to type: string

When present, the value provided will be split based by this value.

Example:

const envSchema = require('env-schema')

const schema = {
  type: 'object',
  required: [ 'ALLOWED_HOSTS' ],
  properties: {
    ALLOWED_HOSTS: {
      type: 'string',
      separator: ','
    }
  }
}

const data = {
  ALLOWED_HOSTS: '127.0.0.1,0.0.0.0'
}

const config = envSchema({
  schema: schema,
  data: data, // optional, default: process.env
  dotenv: true // load .env if it's there, default: false
}) 

// config.data => ['127.0.0.1', '0.0.0.0']

Acknowledgements

Kindly sponsored by Mia Platform and NearForm.

License

MIT