Improve Redis::Store monkey-patch robustness

config/initializers/redis-store-fix-expiry.rb

@@ -4,13 +4,36 @@ module Gitlab
   class Redis
     class Store
       module Namespace
+        # Redis::Store#expire in redis-store 1.1.4 does not respect namespaces;
+        # this new method does.
         def setex(key, expires_in, value, options=nil)
           namespace(key) { |key| super(key, expires_in, value) }
         end
 
+        # Redis::Store#expire in redis-store 1.1.4 does not respect namespaces;
+        # this new method does.
         def expire(key, expires_in)
           namespace(key) { |key| super(key, expires_in) }
         end
+
+        private
+
+        # Our new definitions of #setex and #expire above assume that the
+        # #namespace method exists. Because we cannot be sure of that, we
+        # re-implement the #namespace method from Redis::Store::Namespace so
+        # that it all Redis::Store instances, whether they use namespacing or
+        # not.
+        #
+        # Based on lib/redis/store/namespace.rb L49-51 (redis-store 1.1.4)
+        def namespace(key)
+          if @namespace
+            yield interpolate(key)
+          else
+            # This Redis::Store instance does not use a namespace so we should
+            # just pass through the key.
+            yield key
+          end
+        end
       end
     end
   end