Teach cache register to support redis cluster hash tags

fixes AE-655

Change-Id: Ib3c5b1516516cb7a85bb1776fd15873efdbad421
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/333088
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Cody Cutrer <cody@instructure.com>
QA-Review: Jacob Burroughs <jburroughs@instructure.com>
Product-Review: Jacob Burroughs <jburroughs@instructure.com>

lib/base/active_record/cache_register.rb

@@ -74,7 +74,7 @@ module ActiveRecord
 
             if key_types.any?
               base_keys.group_by { |key| Canvas::CacheRegister.redis(key, ::Shard.current) }.each do |redis, node_base_keys|
-                node_base_keys.map { |k| key_types.map { |type| "#{k}/#{type}" } }.flatten.each_slice(1000) do |slice|
+                node_base_keys.map { |k| key_types.map { |type| "{#{k}}/#{type}" } }.flatten.each_slice(1000) do |slice|
                   redis.del(*slice)
                 end
               rescue Redis::BaseConnectionError
@@ -84,7 +84,7 @@ module ActiveRecord
             if multi_key_types.any?
               base_keys.each do |base_key|
                 multi_key_types.each do |type|
-                  MultiCache.delete("#{base_key}/#{type}", { unprefixed_key: true })
+                  MultiCache.delete("{#{base_key}}/#{type}", { unprefixed_key: true })
                 end
               end
             end
@@ -109,7 +109,7 @@ module ActiveRecord
 
           prefer_multi_cache = prefer_multi_cache_for_key_type?(key_type)
           redis = Canvas::CacheRegister.redis(base_key, ::Shard.shard_for(global_id), prefer_multi_cache:)
-          full_key = "#{base_key}/#{key_type}"
+          full_key = "{#{base_key}}/#{key_type}"
 
           RequestCache.cache(full_key) do
             # try to get the timestamp for the type, set it to now if it doesn't exist

lib/base/active_support/cache_register.rb

@@ -75,7 +75,7 @@ module ActiveSupport
           redis = Canvas::CacheRegister.redis(base_obj_key, batch_object.shard)
 
           instrument(:read, name, options) do |payload|
-            keys_to_batch = batched_keys.map { |type| "#{base_obj_key}/#{type}" }
+            keys_to_batch = batched_keys.map { |type| "{#{base_obj_key}}/#{type}" }
             now = Time.now.utc.to_fs(batch_object.cache_timestamp_format)
             # pass in the base key, followed by the intermediate keys (that the script will pull and append to the base)
             keys = [key] + keys_to_batch

spec/lib/canvas/cache_register_spec.rb

@@ -423,7 +423,7 @@ describe Canvas::CacheRegister do
     end
 
     it "uses multi-cache delete when clearing a configured key" do
-      key = Account.base_cache_register_key_for(Account.default) + "/feature_flags"
+      key = "{#{Account.base_cache_register_key_for(Account.default)}}/feature_flags"
       allow(Canvas::CacheRegister).to receive(:can_use_multi_cache_redis?).and_return(true)
       expect(Canvas::CacheRegister).to_not receive(:redis)
       expect(MultiCache).to receive(:delete).with(key, { unprefixed_key: true })

spec/lib/ha_store_spec.rb

@@ -144,11 +144,11 @@ describe ActiveSupport::Cache::HaStore do
       Timecop.freeze do
         now = Time.now.utc.to_s(Account.cache_timestamp_format)
         base_key = Account.base_cache_register_key_for(Account.site_admin)
-        full_key = base_key + "/feature_flags"
+        full_key = "{#{base_key}}/feature_flags"
         expect(Canvas::CacheRegister.lua).to receive(:run).with(:get_key, [full_key], [now], store.redis).and_return("cool beans")
         expect(Account.site_admin.cache_key(:feature_flags)).to eq("accounts/#{Account.site_admin.global_id}-cool beans")
         # doesn't use it for other key types
-        expect(Canvas::CacheRegister.lua).to receive(:run).with(:get_key, [base_key + "/global_navigation"], [now], Canvas.redis).and_return(now)
+        expect(Canvas::CacheRegister.lua).to receive(:run).with(:get_key, ["{#{base_key}}/global_navigation"], [now], Canvas.redis).and_return(now)
         expect(Account.site_admin.cache_key(:global_navigation)).to eq("accounts/#{Account.site_admin.global_id}-#{now}")
       end
     end