defenv

defenv

A Clojure library designed to make working with environment variables easier.

Prerequisites

You’ll need Java 8 and Leiningen.

Usage

Say you want to define a binding in a namespace that is filled in by the value specified in an environment variable. Here’s the very simplest way to do it:

(require '[defenv.core :refer [defenv]])

(defenv system-path "PATH")

Then, if you run @system-path you will see the value of that environment variable.

The project documentation contains much more example usage.

Also, you could try running DEFENV_TESTING=bob lein usage

Questions I imagined you might ask

Why does `defenv` make delayed bindings?

Well, the project contains a bit of other magic. If you don’t make a binding to a variable optional, an exception will be thrown when it is dereferenced if it isn’t set. We don’t want these exceptions to be thrown during compile time. Therefore, they must be delayed.

Why can't I load property files and declare multiple
environments in my `project.clj` and stuff?

This library was designed for https://12factor.net/ apps

License

Copyright © 2019 Stephen Starkey

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.