check-env

Makes sure that all required environment variables are set.

Install

$ npm install --save check-env

Usage

var checkEnv = require('check-env');
checkEnv(['REQUIRED_VAR', 'OTHER_VAR', 'ENV_VAR']);
// => Throws an error if one of the variables aren't set.

CLI Usage

1. Install as a project dependency as above
2. Add to a lifecycle script such as prestart
3. npm start will bail out (exit(1)) with a hard to miss error message if environment variables are not set

Example:

In package.json:

{
  "prestart": "check-env AWS_KEY MONGO_URL",
  "start": "node index.js"
}

$ echo $MONGO_URL
# (nothing)

$ npm start
 ________________________________________
< Missing environment variable MONGO_URL >
 ----------------------------------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||

$ echo $?
1