Ad-hoc mixing of multiple .env files into an Environment to run shell Commands in

No a big thing, just mixing up multiple .env config files into an ad-hoc enviroment to run your application in. Usually in development, not production.

This for example makes up an env on the fly combined from three files:

$ multi-env .env.sqs.dev .env.db.local .env.saas.staging -- ./bin/app-under-development

Like when you have a programm which connects with two different databases, an AWS SQS queue and a external SaaS API. To run this script in dev mode you need to configure all of them, but depending on what you actually work on, you need a different set-up. In this case this are three envs combined, and possibilities multiply. Add test, staging and production and combinations go up beyond what you can handle in a single .env file.

Add as many .env files you like, end that list with -- and have your regular cmdline following right after it. The above example results in constructing and executing this shell command:

$ (set -a; source .env.sqs.dev && source .env.db.local && source .env.saas.staging && ./bin/app-under-development)

Frameworks like laravel support a .env file directly, and in testing even overload it automatically from .env.testing. This script is for such needs, but in a generic way. Packages like .dotenv do similar things, but for from inside a node.js app itself. This here is for the cmdline.

All of this is guided by the idea of 12 Factors, go read it, if you haven't. Seriously.

have fun