Put CACHE_NAMESPACE in the Gitlab::Redis module

config/application.rb

@@ -7,8 +7,6 @@ Bundler.require(:default, Rails.env)
 require_relative '../lib/gitlab/redis'
 module Gitlab
-  REDIS_CACHE_NAMESPACE = 'cache:gitlab'
-
   class Application < Rails::Application
     # Settings in config/environments/* take precedence over those specified here.
     # Application configuration should go into files in config/initializers
@@ -70,7 +68,7 @@ module Gitlab
     end
     redis_config_hash = Gitlab::Redis.redis_store_options
-    redis_config_hash[:namespace] = REDIS_CACHE_NAMESPACE
+    redis_config_hash[:namespace] = Gitlab::Redis::CACHE_NAMESPACE
     redis_config_hash[:expires_in] = 2.weeks # Cache should not grow forever
     config.cache_store = :redis_store, redis_config_hash

lib/gitlab/redis.rb

 module Gitlab
   class Redis
+    CACHE_NAMESPACE = 'cache:gitlab'
+
     attr_reader :url
     # To be thread-safe we must be careful when writing the class instance

lib/tasks/cache.rake

@@ -9,7 +9,7 @@ namespace :cache do
       loop do
         cursor, keys = redis.scan(
           cursor,
-          match: "#{Gitlab::REDIS_CACHE_NAMESPACE}*", 
+          match: "#{Gitlab::Redis::CACHE_NAMESPACE}*", 
           count: CLEAR_BATCH_SIZE
         )