I have been around for steps which help me integrate docker swarm with flocker. Here is the link that helped me. Have a look http://blog.calsoftinc.com/2016/09/docker-swarm-flocker-driver-integration.html
If you have a compatible storage platform, REX-Ray work with Docker Swarm today. Checkout Storage Persistence and Failover with Minecraft using REX-Ray and Docker Swarm Mode in the {code} Labs