feat(bandwith_throttling): Adds a throttling middleware to keep bots …

…out of the api

lib/yodatra/api_formatter.rb

@@ -15,7 +15,7 @@ def _call(env)
 
       status, headers, response = @block.yield(status, headers, response) unless @block.nil?
 
-      headers['Content-Length'] = response.first.length.to_s unless response.nil? || response.first.nil?
+      headers['Content-Length'] = response.first.length.to_s unless response.nil? || !response.respond_to?(:first) || response.first.nil?
 
       [status, headers, response]
     end

lib/yodatra/throttling.rb

@@ -0,0 +1,26 @@
+begin
+  require 'redis'
+
+  module Yodatra
+    class Throttle
+      def initialize(app, opts)
+        @app = app
+        @redis = Redis.new opts[:redis_conf]
+        @rpm = opts[:rpm] || 100
+      end
+
+      def call(env)
+        req = Rack::Request.new(env)
+        key = "throttle:#{req.ip}"
+        @redis.incr(key) == 1 && @redis.expire(key, 60)
+        if @redis.get(key).to_i > @rpm
+          Rack::Response.new('Too many API calls', 403)
+        else
+          @app.call(env)
+        end
+      end
+    end
+  end
+rescue LoadError
+  raise "Error: in order to use Yodatra's throttling middleware you will need Redis. Add 'redis' to your Gemfile or simply gem install 'redis'"
+end