Set the standard health_check options to include the cache check.

config/initializers/health_check.rb

-# HealthCheck.setup do |config|
-#   # Text output upon success
-#   config.success = 'success'
-#
-#   # Timeout in seconds used when checking smtp server
-#   config.smtp_timeout = 30.0
-#
-#   # http status code used when plain text error message is output
-#   # Set to 200 if you want your want to distinguish between partial (text does not include success) and
-#   # total failure of rails application (http status of 500 etc)
-#   config.http_status_for_error_text = 500
-#
-#   # http status code used when an error object is output (json or xml)
-#   # Set to 200 if you want your want to distinguish between partial (healthy property == false) and
-#   # total failure of rails application (http status of 500 etc)
-#   config.http_status_for_error_object = 500
-#
-#   # You can customize which checks happen on a standard health check
-#   config.standard_checks = [ 'database', 'migrations', 'custom' ]
-#
-#   # You can set what tests are run with the 'full' or 'all' parameter
-#   config.full_checks = ['database', 'migrations', 'custom', 'email', 'cache']
-#
-#   # Add one or more custom checks that return a blank string if ok, or an error message if there is an error
-#   config.add_custom_check do
-#      any code that returns blank on success and non blank string upon failure
-#   end
-# end
+HealthCheck.setup do |config|
+  config.standard_checks = [ 'database', 'migrations', 'cache' ]
+end