Deploy 3 node cassandra cluster with Docker Swarm

Create overlay network

docker network create --driver overlay --scope swarm cassandra-net

Download and deploy cassandra 3 node compose file

wget https://raw.githubusercontent.com/portworx/px-docs/gh-pages/scheduler/docker/portworx-cassandra3node.yaml
docker stack deploy --compose-file portworx-cassandra3node.yaml cassandra