ENVELOAD

A node library to load disparate environment variables into a single object, with additional parsing and validation.

What Is This Good For?

• Loading a bunch of environment variables into a single object.
• Using Meteor? Loading a bunch of environment variables into Meteor.settings.
• Validating that environment variables exist during startup; just ignore the object it returns.

Usage

npm i --save enveload

Then, as early as possible in your app's startup server code (after require('dotenv') if you're using it :)

const settings = require('enveload')({
  FACEBOOK_API_KEY: true,
  GOOGLE_API_KEY: 'google.apiKey',
  GOOGLE_CLIENT_ID: 'public.google.clientId',
})

API

require('enveload')(mapping, options)

Mapping

mapping is a map of envvar names to mapping options. The most simple mapping is:

mapping = {
  GOOGLE_API_KEY: true
}
// settings.googleApiKey === process.env.GOOGLE_API_KEY

You can specify which key things should end up in. The string you provide is passed to lodash.set, and supports anything that supports.

mapping = {
  FACEBOOK_API_KEY: 'facebook.key'
}
// settings.facebook.key === process.env.FACEBOOK_API_KEY

Obviously JSON can represent much more than a simple string. By default, this library will attempt to JSON-parse any envvar you provide it in this map.

// process.env.REQUEST_LIMIT=5
// process.env.WHITELISTED_IPS=["1.1.1.1","2.2.2.2","3.3.3.3"]
mapping = {
  REQUEST_LIMIT: true,
  WHITELISTED_IPS: true,
}
// typeof settings.requestLimit === 'number'
// typeof settings.whitelistedIps === 'object' (its an array :)

Options

By default, enveload will throw an error if a requested environment variable isn't found or contains a falsey value (essentially, empty string). This can be tweaked on a global basis with the options object

require('enveload')({ ...mapping }, {
  onMissing: 'error',
  onMissing: 'log',
  onMissing: 'ignore',
})

If you desire to use onMissing:log, enveload will simply write a useful log with console.warn. If you want to customize the log a little bit, you can optionally provide a global configuration parameter like so:

require('enveload')({ ...mapping }, {
  onMissing: 'log',
  log: (missingEnv) => {
    // ... do whatever you want here, use your own logging libraries, etc.
  }
})

By default, enveload will JSON.parse every environment variable it comes across and throw away the error if there is one. You can tweak this behavior with two options on each mapping.

require('enveload')({
  // dontParse will avoid the parsing alltogether and just copy the string into the final object
  WHITELISTED_IPS: { to: 'whitelistedIps', dontParse: true },
  // requireParse will bubble-up the error if the JSON.parse fails
  BLACKLISTED_USERS: { to: 'blacklistedUsers', requireParse: true },
})

You can also load a single environment variable into different places inside the resulting object, if your use-case demands it.

require('enveload')({
  SECRET_API_TOKEN: { to: [ 'location1', 'location2.location3' ] },
})

Meteor Support

This library is especially useful for assembling a Meteor.settings object from multiple envvars instead of a single big METEOR_SETTINGS envvar.

One cool thing: Specifying the first nested object as public works exactly as you'd expect; the value will available to clients.

mapping = {
  GOOGLE_CLIENT_ID: 'public.google.clientId'
}
// settings.public.google.clientId === process.env.GOOGLE_CLIENT_ID (on server)

The code in your Meteor app might look like:

Meteor.settings = Object.assign(Meteor.settings, require('enveload')({
  GOOGLE_API_KEY: 'google.apiKey',
  GOOGLE_CLIENT_KEY: 'public.google.clientKey',
}))