stavka
Stavka (Ставка) is the high command of your clojure application, which manages configuration from various sources.
Features
- Extensible configuration sources and formats
- Sources:
- Formats:
- Environment variables
(env) - JVM options (-D)
(options) - Commandline options with tools.cli parser
(cli args cli-parser), enabled whenclojure.tools.clion classpath - EDN
(edn) - JSON
(json), enabled whencheshireon classpath - YAML
(yaml), enabled whenclj-yamlon classpath - Properties
(property)
- Environment variables
- Reloading by
- Watching file system
(watch), enabled whenhawkon classpath - Watching file system
(watch2)using beholder as backend, enabled whenheholderon classpath - Polling the source
(poll)
- Watching file system
- Listeners for value changing
(on-change!) - Type conversion
($l) ($f) ($b) ($s)
Usage
Setup
Use stavka with component or mount. You can have multiple config instance and manage life-cycle of updater.
(require '[stavka.core :as sta :refer :all])
;; Use stavka with mount
(defstate config
:start
;; load configuration from multiple sources and merge them like
;; clojure.core/merge.
(sta/using
;; using environment variables by default
(env)
;; also load edn from classpath
(edn (classpath "/default.edn"))
;; load another properties from filesystem, and watch is for change
(properties (watch (file "/etc/stavka.properties")))
;; and fetch a remote json configuration. check every 10 seconds
;; for update.
(json (poll (url "http://somehost/configuration/my.json") 10000)))
:stop (stop-updaters! config))
;; Use stavka with component
(defrecord StavkaConfiguration [config]
component/Lifecycle
(start [component]
(assoc component :config
(sta/using
(env)
(edn (classpath "/default.edn"))
(properties (watch (file "/etc/stavka.properties")))
(json (poll (url "http://somehost/configuration/my.json") 10000)))))
(stop [component]
(stop-updaters! config)
(assoc component :config nil)))Configuration format:
ENV
export SOME_CONFIG_KEY="some-value"EDN
{:some {:config {:key "some-value"}}}JSON
{
"some": {
"config": {
"key" : "some-value"
}
}
}Properties
some.config.key=some-valueYaml
some:
config:
key: some-valueGet configuration item:
;; get configuration
($ config :some.config.key)
;; get configuration with type convertion
;; $l: as long
;; $f: as double
;; $s: as string
;; $b: as boolean
($l config :some.config.key)Global config
And you can still use stavka globally:
(sta/global!
(env)
(edn (classpath "/default.edn"))
(properties (watch (file "/etc/stavka.properties")))
(json (poll (url "http://somehost/configuration/my.json") 10000)))
;; use double-$ to access global config
($$ :some.config.key)
($$l :some.config.key)Listeners
Add change listener on some key when you have updater configured:
(on-change! config :some.config.key
(fn [new-value previous-value]
))License
Copyright © 2018 Ning Sun
Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.
Donation
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