FIX: report cached controller and action to loggers

Previously we would treat all cached hits in anon cache as "other"

This hinders analysis of cache performance and makes logging inaccurate

lib/middleware/anonymous_cache.rb

@@ -134,6 +134,7 @@ module Middleware
       end
 
       MIN_TIME_TO_CHECK = 0.05
+      ADP = "action_dispatch.request.parameters"
 
       def should_force_anonymous?
         if (queue_time = @env['REQUEST_QUEUE_SECONDS']) && get?
@@ -153,10 +154,13 @@ module Middleware
         !!(!has_auth_cookie? && get? && no_cache_bypass)
       end
 
-      def cached
+      def cached(env = {})
         if body = $redis.get(cache_key_body)
           if other = $redis.get(cache_key_other)
             other = JSON.parse(other)
+            if req_params = other[1].delete(ADP)
+              env[ADP] = req_params
+            end
             [other[0], other[1], [body]]
           end
         end
@@ -169,7 +173,7 @@ module Middleware
       # NOTE in an ideal world cache still serves out cached content except for one magic worker
       #  that fills it up, this avoids a herd killing you, we can probably do this using a job or redis tricks
       #  but coordinating this is tricky
-      def cache(result)
+      def cache(result, env = {})
         status, headers, response = result
 
         if status == 200 && cache_duration
@@ -180,6 +184,13 @@ module Middleware
             parts << part
           end
 
+          if req_params = env[ADP]
+            headers_stripped[ADP] = {
+              "action" => req_params["action"],
+              "controller" => req_params["controller"]
+            }
+          end
+
           $redis.setex(cache_key_body,  cache_duration, parts.join)
           $redis.setex(cache_key_other, cache_duration, [status, headers_stripped].to_json)
 
@@ -218,7 +229,7 @@ module Middleware
 
       result =
         if helper.cacheable?
-          helper.cached || helper.cache(@app.call(env))
+          helper.cached(env) || helper.cache(@app.call(env), env)
         else
           @app.call(env)
         end

spec/components/middleware/request_tracker_spec.rb

@@ -277,12 +277,24 @@ describe Middleware::RequestTracker do
       tracker = Middleware::RequestTracker.new(cache)
 
       uri = "/path?#{SecureRandom.hex}"
-      tracker.call(env("REQUEST_URI" => uri, "ANON_CACHE_DURATION" => 60))
+
+      request_params = {
+        "a" => "b",
+        "action" => "bob",
+        "controller" => "jane"
+      }
+
+      tracker.call(env("REQUEST_URI" => uri, "ANON_CACHE_DURATION" => 60, "action_dispatch.request.parameters" => request_params))
 
       expect(@data[:cache]).to eq("store")
 
       tracker.call(env("REQUEST_URI" => uri, "ANON_CACHE_DURATION" => 60))
       expect(@data[:cache]).to eq("true")
+
+      # not whitelisted
+      request_params.delete("a")
+
+      expect(@env["action_dispatch.request.parameters"]).to eq(request_params)
     end
 
     it "can correctly log detailed data" do