Class: Determinator::Retrieve::Routemaster

Inherits:
Object
  • Object
show all
Defined in:
lib/determinator/retrieve/routemaster.rb

Overview

A storage and retrieval engine for Determinator using routemaster-drain.

To use this correctly you will need the following environment variables set to appropriate values for your instance of Routemaster:

ROUTEMASTER_DRAIN_TOKENS ROUTEMASTER_DRAIN_REDIS ROUTEMASTER_CACHE_REDIS ROUTEMASTER_CACHE_AUTH ROUTEMASTER_QUEUE_NAME ROUTEMASTER_CALLBACK_URL

Constant Summary collapse

CALLBACK_PATH = 
(URI.parse(ENV['ROUTEMASTER_CALLBACK_URL']).path rescue '/events').freeze

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(discovery_url:) ⇒ Routemaster

Returns a new instance of Routemaster.

Parameters:

  • :discovery_url (String) —

    The bootstrap URL of the instance of Florence which defines Features.



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# File 'lib/determinator/retrieve/routemaster.rb', line 25

def initialize(discovery_url:)
  client = ::Routemaster::APIClient.new(
    response_class: ::Routemaster::Responses::HateoasResponse
  )
  @routemaster = client.discover(discovery_url)
  @routemaster_app = ::Routemaster::Drain::Caching.new(
    siphon_events: { 'features' => RoutemasterFeatureIdCacheWarmer }
  )
end

Instance Attribute Details

#routemaster_app ⇒ Object (readonly)

Returns the value of attribute routemaster_app.



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# File 'lib/determinator/retrieve/routemaster.rb', line 20

def routemaster_app
  @routemaster_app
end

Class Method Details

.index_cache_key(feature_name) ⇒ Object 



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# File 'lib/determinator/retrieve/routemaster.rb', line 66

def self.index_cache_key(feature_name)
  "determinator_index:#{feature_name}"
end

Instance Method Details

#configure_rails_router(route_mapper) ⇒ Object

Automatically configures the rails router to listen for Features with routemaster

Parameters:

  • route_mapper (ActionDispatch::Routing::Mapper) —

    The rails mapper, 'self' within the routes.draw block



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# File 'lib/determinator/retrieve/routemaster.rb', line 62

def configure_rails_router(route_mapper)
  route_mapper.mount routemaster_app, at: CALLBACK_PATH
end

#retrieve(feature_name) ⇒ Object 



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# File 'lib/determinator/retrieve/routemaster.rb', line 35

def retrieve(feature_name)
  key = self.class.index_cache_key(feature_name)
  feature_id = ::Routemaster::Config.cache_redis.get(key)
  return unless feature_id

  obj = @routemaster.feature.show(feature_id)

  Feature.new(
    name:          obj.body.name,
    identifier:    obj.body.identifier,
    bucket_type:   obj.body.bucket_type,
    target_groups: obj.body.target_groups.map { |tg|
      TargetGroup.new(
        rollout: tg.rollout,
        constraints: tg.constraints.to_h
      )
    },
    variants:      obj.body.variants.to_h,
    overrides:     obj.body.overrides.to_h
  )
rescue ::Routemaster::Errors::ResourceNotFound
  nil
end