milieu

The environmentally friendly configuration tool.

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Features:

• Set up environment-specific configuration for your Clojure application, using the popular YAML file format.

• Access config values:

  Specifying config values:

  (config/value :my :config :value)

  This will access the value in

    dev:
      my:
        config:
          value: 2
  
    ...
  
    test:
      my:
        config:
          value: 3

  Another example:

    dev:
      smiles:
        - mary: "8-)"
          fred: ":-|"
        - mary: "*_*"
          fred: "-__-"

  Access using:

    (config/value :smiles 0 :mary) => "8-)"
    (config/value :smiles 1 :fred) => "-__-"

  Specifying config values as optional:

  (config/value| :my :config :value) ; same as config/value except that because it is optional it doesn’t warn when not found
  (config/value| [:my :config :value] "alternate value") ; provide alternate value

• Optionally auto-load config file.

  • using the default filename of "configure.yml" enables autoload
  • any other config file name can be specified by calling load-config

• Bind the environment within a calling context using with-env.

    (config/with-env env
      (when (config/value :some :setting) ... ))

• Specify the default environment using the MILIEU_ENV system variable.

• Override environment-specific settings using arguments to your command-line application.

    (config/commandline-overrides! args)
    (config/with-env env
      ... )

• In cases where the environment can be variable, code evaluation can by restricted in with-env or only-env, or more generally conditional using if-env and when-env.

    ;; If env is prod, the code in the body will not be exercised,
    ;; an exception is thrown instead:
    (defn -main [env & args]
      (config/with-env [env :only [:test :dev]] ,,,))

  Alternatively (for example if you aren't in the context of a with-env)...

    ;; If env is prod, the code in the body will not be exercised,
    ;; an exception is thrown instead:
    (config/only-env [:test :dev] ,,,)

  The following forms are general purpose conditionals (not assertions of environment restrictions).

    (config/if-env :test "hello" "goodbye")

    (config/when-env :dev ,,,)

• Warning when non-optional config setting is not found (you can disable this warning by setting system environment variable MILIEU_QUIET).

Use

Installation

http://clojars.org/rplevy/milieu

Getting Started

(ns example.core
  (:require [milieu.config :as config]))

Example

(defn -main [env & args]
  (config/commandline-overrides! args)
  (config/with-env env
    (when (config/value| :some :setting) ,,,

Command-line Override

$ myprogram prod --fou.barre Fred --some.setting 127.0.0.1
$ myprogram dev --smiles.1.mary ":D"

License

Author: Robert Levy / @rplevy

Acknowledgments: @alanpeabody, @S11001001, @AlexBaranosky, @khdegraaf

Copyright © 2012 Draker Labs

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