Redis::Central

redis-central providers a helper for providing access and configuration to a single per-application/thread, optionally namespaced, redis client.

gem install redis-central

At it's most basic (and it's all pretty basic), redis-central provides your classes and objects with a "redis" helper method for accessing a single redis client. In this form it will return a Redis instance

require 'redis-central'

class User

  include Redis::Central
  
  attr_accessor :id, :name
  
  def self.find(id)
    user = User.new
    user.name = redis.get "users:#{id}:name"
  end
  
  def save
    redis.set "users:#{id}:name", name
  end
  
end

Both the class and its instances will have access to the redis method. Other classes can also include Redis::Central, and these will have access to the same redis client instance.

Configuration options which would normally be passed to the Redis instance can be set on the Redis::Central class, eg.

Redis::Central.port = 1234

The real motivation for this library, however, is to provide an easy means of centrally namespacing redis keys for an application.

This is particularly useful where a single redis server is being used for multiple deployments of the same application, or for applications which share a model/ models which are persisted through redis, or simply scenarios were redis keys could clash between applications.

So for instance you could have an initializer containing something like this:

app_name = RAILS_ROOT.split(File::SEPARATOR).last
Redis::Central.namespace = app_name

In this scenario calls to the redis method will return an instance of Redis::Namespace, namespaced with the given setting. All queries to this object will then be prefixed accordingly.

bundle install
rake test

Si Wilkins