From 87f628d0c10c8df5d042e27e8fd5c5ae3ae50d7e Mon Sep 17 00:00:00 2001
From: Will Kimeria <william.kimeria@lookout.com>
Date: Fri, 14 Mar 2014 11:50:59 -0700
Subject: [PATCH] If redis client throws exception, don't raise it

For throttling, when the redis client throws an exception, the request
ends up getting rate limited. Modify this to be similar to how
ActiveSupport.MemCacheStore functions (the read, write and increment
methods do not raise exceptions)
---
 lib/rack/attack/store_proxy.rb |  6 ++++++
 spec/rack_attack_cache_spec.rb | 28 ++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/lib/rack/attack/store_proxy.rb b/lib/rack/attack/store_proxy.rb
index 0c65aee..6f6a507 100644
--- a/lib/rack/attack/store_proxy.rb
+++ b/lib/rack/attack/store_proxy.rb
@@ -26,6 +26,8 @@ module Rack
 
         def read(key)
           self.get(key)
+          rescue Redis::BaseError
+            nil
         end
 
         def write(key, value, options={})
@@ -34,6 +36,8 @@ module Rack
           else
             self.set(key, value)
           end
+          rescue Redis::BaseError
+            nil
         end
 
         def increment(key, amount, options={})
@@ -43,6 +47,8 @@ module Rack
             self.expire(key, options[:expires_in]) if options[:expires_in]
           end
           count.value if count
+          rescue Redis::BaseError
+            nil
         end
 
       end
diff --git a/spec/rack_attack_cache_spec.rb b/spec/rack_attack_cache_spec.rb
index 3f7fac9..0016ff9 100644
--- a/spec/rack_attack_cache_spec.rb
+++ b/spec/rack_attack_cache_spec.rb
@@ -78,6 +78,34 @@ if ENV['TEST_INTEGRATION']
 
     end
 
+    describe "should not error if redis is not running" do
+      before {
+        @cache = Rack::Attack::Cache.new
+        @key = "rack::attack:cache-test-key"
+        @expires_in = 1
+        # Use ip reserved for documentation to ensure it does not exist
+        # http://tools.ietf.org/html/rfc5737
+        @cache.store = ActiveSupport::Cache::RedisStore.new(:host => '203.0.113.0', :port => 3333)
+      }
+      describe "write" do
+        it "should not raise exception" do
+          @cache.write("cache-test-key", "foobar", 1)
+        end
+      end
+
+      describe "read" do
+        it "should not raise exception" do
+          @cache.read("cache-test-key")
+        end
+      end
+
+      describe "do_count" do
+        it "should not raise exception" do
+          @cache.send(:do_count, @key, @expires_in)
+        end
+      end
+    end
+
   end
 else
   puts 'Skipping cache store integration tests (set ENV["TEST_INTEGRATION"] to enable)'