Reusing DotEnv Configuration with the Shell

A common security pattern is to add environment-specific configuration and secrets into a local, unversioned file. You’re probably already doing this with a tool called DotEnv. Let’s see how we can reuse that between PHP and the shell.

If you’re using Laravel, or any other recent framework or PHP project, you’re probably familiar with the DotEnv project. If you’ve ever copied a .env.example file to .env then you are!

Basically, we can use the .env file to specify local environment variables for our PHP script - as long as DotEnv is loaded and being initialized.

Sometimes it’s necessary to use those same variables with other tooling - like local shell scripts. Luckily, this is very easy!

Here’s the situation. At the root of our project, we have our .env file with a URL variable. Then, we have a bin/ping script that will ping our project via that URL. We don’t want to have to specify it twice. Let’s see how this works.

APP_URL=https://my-website.local

#!/usr/bin/env bash

source "`dirname $0`/../.env"
ping $APP_URL

Now, your environment variables are available to the script as well. When you call the dirname command, you get the current directory of the running script. Since we know where it’s located, and where our .env file is, we can then use that to source it. This then makes all of the variables available in the current environment.