cron image does not respect all ENV vars

I run a local swarm without a shared filesystem.  The cron container can run on a host different from the registry.  The cron container doesn't appear to respect all the ENV vars (like COMANAGE_REGISTRY_ENABLE_PLUGIN and the email related ones).  The container  can't find additional plugins like FileSource.  There is no way to control having registry and cron run on the same host in a docker swarm.