dotenv

A Clojure library designed to load environment variables. This was born out of the frustration of using existing libraries and from the fact that I find it less than ideal to introduce a new standard regarding env files.

It loads them from (by order of priority):

• Application environment specific .env file (defaults to .env.development)
• .env file
• Properties
• System Environment Variables

Where to put your env vars?

Dotenv will pull env vars from your system and property files as expected.
Also, it will pull env vars from local .env file.
Now, if you need "app environment" specific env vars, you can create "app environment specific env files" such as:

• .env.development
• .env.test

And they will be loaded if your app is running on any of those environments.

But, how do you set your app environment?
You simply set APP_ENV on either your system, your command or on .env

Example:

If you set your .env with:

APP_ENV=dev
SOME_VAR=DotEnvValue

and you have a .env.dev file with:

NEW_VAR=123
SOME_VAR=DotEnvDotDevValue

within your app, you'll have the following env vars (among System defined env vars):

APP_ENV=dev
NEW_VAR=123
SOME_VAR=DotEnvDotDevValue

Notice how SOME_VAR is overriden.

Supported env file formats

dotenv.clj is quite permissive in how you declare your env vars within the env files.
The following declarations are all valid:

SOME=value
  ANOTHER=different-value

AND_HOW="about something else?"
# COMMENTED_OUT="won't be loaded"
export VERY_RELEVANT="thing of general use"

IT_CAN = "even support spacing"
ALSO_HANDLES="quotations \"well enough\""

Note that empty lines are also valid as they are simply ignored.

Install

Add the dependency to you project.clj:

:dependencies [[lynxeyes/dotenv "1.1.0"]]

and lein deps!

Usage

Dotenv was built to supply 2 major pieces of information:

• app-env - a String with the currently running app env (development, production, test). Defaults to "development".
• env - a function to access the environment vars map

To use it, require it wherever you need it:

(require '[dotenv :refer [env app-env]])

Now, app-env will tell you which environment is your app running on.

=> app-env
"development"

And env will allow you to refer to environment variables both by String or Keyword:

=> (env "SOME_ENV_VAR")
"whatever we set on the var"

or

=> (env :SOME_ENV_VAR)
"whatever we set on the var"

You may also pass no arguments to env and get the full environment variable map back:

=> (env)
{"SOME_VAR" "some value" ....too big for me to actually represent here..sorry.... }

License

Copyright © 2017 Ivo Jesus

Distributed under the MIT Public Licence. Use it as you will. Contribute if you have the time.