cornerstone

A re-usable foundation for Clojure projects containing defaults management.

Usage

File driven

The simplest use case is file-driven defaults, where edn configuration is stored at resources/config/dev.edn as follows:

{:foo "bar"}

This can then be read in the application as follows:

(use 'cornerstone.config)
(bootstrap {:name "dev"})
(config :foo) ;; bar

Setting another location for the configuration files can be done with the :config-dir parameter in bootstrap:

(bootstrap {:name "dev" :config-dir "/path/to/my/config"})

Environment overrides

Sometimes we'll want to override what's in the file with environment variables, as used for example by Heroku. Anything defined in the file will be overridden by an identically named environment variable.

For example, if your edn configuration is as follows:

{:foo "bar"}

And the environment variable is set as foo=baz then the following code will yield baz:

(use 'cornerstone.config)
(bootstrap {:name "dev"})
(config :foo) ;; baz

Environment variables only

If you want to drive configuration purely by environment variables that can be achieved by providing a prefix:

myapp-foo=bar

(use 'cornerstone.config)
(bootstrap {:name "dev" :env-prefix "myapp"})
(config :foo) ;; bar

License

Copyright © 2013 oliyh

Distributed under the Eclipse Public License, the same as Clojure.