Clojure(script) functions for accessing config data from the ENV or INI files

• Introduction
• Usage
  • Clojure
  • Clojurescript
• License

Config/INI files are an old stand-by for configuration. Even now, projects such as AWS and OpenStack clients use the Config/INI format. Still, environment variables reign supreme in different deployment configurations, so it would be nice to use them both, with ENV settings overriding Config/INI ones. Thus this project was created.

This project uses the clojure-ini project to read Config/INI files. For Clojurescript support, Node.js, NPM, and lein-npm are used. JS INI file support is provided by the Node.js better-require library.

Data from the environment and a given configuration are loaded into the same data structure, one keyed off of :env and the other off of :ini. This is obvious after loading the data:

(def data (env-ini/load-data "~/.aws/credentials"))
(pprint data)

{:ini
 {:alice
  {:aws-access-key-id "AAAAAAAABBBBBBBBCCCD",
   :aws-secret-access-key "ZZZZZZZZZZZZZXXXXXXXXXXXXXXXXXXxYYYYY123"}},
 :env
 {:aws-access-key-id "AAAAAAAABBBBBBBBCCCD",
  ...}}

By default, it is assumed that a key mykey in section mysection of a Config/INI file would be overridden with the environment variable MYSECTION_MYKEY:

clojusc.env-ini.dev=> (env-ini/get data :mysection :mykey)

If the envionment and configuration key don't act in that way, you can provide two different keys, the env one first, and then the config key:

clojusc.env-ini.dev=> (env-ini/get data :my-env-key :mysection :my-ini-key)

This would result in the environment variable MY_ENV_KEY being looked up. If and only if a nil result was obtained, the loaded Config/INI data would be checked for the value associated with the :my-ini-key key in the section :mysection.

Note that environment variable names are loaded as lower-cased keywords (with underscores converte to dashes).

The usage is exactly the same from Clojurescript. In a Node.js Clojurescript REPL, let's bring in the required namespace:

$ make node-repl

clojusc.env-ini.node-dev=> (require '[clojusc.env-ini.core :as env-ini])

Then run the same code as above:

clojusc.env-ini.node-dev=> (def data (env-ini/load-data "~/.aws/credentials"))
clojusc.env-ini.node-dev=> (pprint data)
...
clojusc.env-ini.node-dev=> (env-ini/get data :mysection :mykey)
clojusc.env-ini.node-dev=> (env-ini/get data :my-env-key :mysection :my-ini-key)

Copyright © 2016-2017, Clojure-Aided Enrichment Center

Copyright © 2016, Element 84, Inc.

Apache License, Version 2.0.