Example Faraday integration with the LDAP protocol, with caching to the database.

ldap.rb

require "faraday"

module Faraday
  class Adapter
    class NetLdap < Faraday::Adapter
      def call(env)
        # LDAP request, and call `save_response(env, status, body, headers)`
        @app.call(env)
      end
    end
  end
end

Faraday::Middleware.register_middleware :net_ldap => Faraday::Adapter::NetLdap

module MyMiddleware
  class Cache < Faraday::Response::Middleware
    def initialize(app, options = {})
      super(app)
      @last_updated = options.fetch(:last_updated)
      @cache        = options.fetch(:cache)
      @expires_in   = options.fetch(:expires_in)
    end
    
    def call(env)
      if Time.now - @last_updated.call >= @expires_in
        super
      end
    end
    
    def on_complete(env)
      @cache.call env[:body] # Assuming env[:body] is array of Ruby hashes
    end
  end
end

connection = Faraday.new("ldap://example.com", connection_options) do |b|
  b.use MyMiddleware::Cache, last_updated: -> { MyModel.max(:created_at) },
                             expires_in: 4.hours,
                             cache: MyModel.method(:create)
  b.adapter :net_ldap
end