FeatureBee For Scala

FeatureBee client for Scala applications

Status

Setup

Add to your build.sbt following resolver with dependency:

resolvers += Resolver.bintrayRepo("tatsu-kondor", "maven")

libraryDependencies += "com.autoscout24" %% "featurebee" % "1.0.77"

Now you can use FeatureBee library.

How To Use

Write a Features trait to access all your features in one place, e.g.:

trait Features {
  def languageDropdown: Feature
  def survey: Feature
}

object Features extends Features {
  private implicit lazy val featureRegistry = StaticJsonFeatureRegistry("featureBee.json")
  override def languageDropdown = Feature("language-dropdown").getOrElse(AlwaysOffFeature)
  override def survey = Feature("survey").getOrElse(AlwaysOffFeature)
}

Add file featureBee.json at your resources or conf folder with JSON that explains behaviour of your feature flags, for example:

[
  {
    "name": "survey",
    "description": "Enables survey",
    "tags": ["our-team", "awesome-feature"],
    "activation": [{ "default": true}]
  },
  {
    "name": "language-dropdown",
    "description": "Shows language dropdown",
    "tags": ["our-team", "awesome-feature"],
    "activation": [{ "default": false}]
  }
]

For deatil information regarding format of JSON see Contract paragraph.

Write a support object which defines how the request from the client is used to extract relevant feature toggle info, like e.g. the language or the browser. For Play apps you may use the already defined PlayClientInfoSupport:

object ControllerClientInfoSupport {
  implicit def requestToClientInfo(implicit requestHeader: RequestHeader): ClientInfo = {
    import PlayClientInfoSupport._
    ClientInfoImpl(userAgent, localeFromCookieValue("culture"), uuidFromCookieValue("as24Visitor"), forcedFeatureToggle)
  }
}

Currently only a static json file inside your deployment is supported, see Contract section below. See the usage of StaticJsonFeatureRegistry above for infos how you specify the location of the feature config file.

Forced Feature Toggling (GodMode)

If you use the PlayClientInfoSupport, you may force feature activation regardless of the conditions you specify in your JSON feature config by setting a query param, a request Header, or a cookie. This order of mentioning the variants is also the order of precedence, so query param has precedence over cookie. All the keys are case insensitive.

Query Param

Use query param featurebee to specify forced / god mode activation of features:

http://yourUrl?featurebee=feature1%3Dtrue%7Cfeature2%3Dfalse

Which decodes to:

http://yourUrl?featurebee=feature1=true|feature2=false)

= is used to assign the true / false value to a feature with the given name and | is used to separate the different features from each other. So we need URL encoding here, so the above forced feature string would decode to:

feature1=true|feature2=false

Request Header

Use header name featurebee or X-Featurebee (case insensitiv) to specify the forced / god mode feature activation.

Example request header value:

feature1=true|feature2=false

Cookie

Use a cookie with name featurebee to specify the forced/god mode feature activation.

Example cookie value:

feature1=true|feature2=false

Contract

The FeatureBee Server returns a list of all defined features.

[{
  "name": "Name of the Feature",
  "description": "Some additional description",
  "tags": ["Team Name", "Or Service name"],
  "activation": [{"culture": ["de-DE"]}]
}]

Conditions is an array of type and values. Supported types are default, culture, userAgentFragments and trafficDistribution.

Each condition can have its own format how the values should look like. Each condition could have multiple values. All conditions have to be fulfilled (logical AND).

The JSON has to fulfill the following requirements:

Name must be set and unique
activation must contain at least one condition
description is mandatory
tags are optional

Copyright

Distributed under the MIT License.

MatthiasKainer / featurebee-scala