Create a swarm with overlay network - virtualbox.

create-swarm-virtualbox.sh

unset DOCKER_HOST DOCKER_MACHINE_NAME DOCKER_MACHINE_NAME DOCKER_TLS_VERIFY DOCKER_CERT_PATH 
export SWARM_TOKEN=$(cat swarm.token)
echo $SWARM_TOKEN 

CONSUL_IP=$(docker-machine ip consul)
_cluster="A"
_master=${_cluster}-0
_cert_home="$HOME/.docker/machine/machines/${_master}"


# create swarm master and copy certs in .docker folder
docker-machine create -d virtualbox --virtualbox-boot2docker-url=./boot2docker-1.8.iso \
    --engine-opt="default-network=overlay:multihost" \
    --engine-opt="kv-store=consul:$(docker-machine ip consul):8500" \
    --engine-label="com.docker.network.driver.overlay.bind_interface=eth1" \
    ${_master}


#docker-machine scp  -r ~/.docker/machine/machines/A-0/ A-0:/home/docker/.docker/
for f in ${_cert_home}/{server.pem,server-key.pem,ca.pem}; do
    docker-machine ssh ${_master} "
        mkdir /home/docker/.docker/${_master}/;
        chown docker:docker /home/docker/.docker/${_master}/;
        "
    docker-machine scp -r  "$f" ${_master}:/home/docker/.docker/${_master}/
    done

# create the swarm processes with bridge.
docker $(docker-machine config ${_master}) run -d \
    --restart="always" \
    --net="bridge" \
        swarm:latest join --addr "$(docker-machine ip ${_master}):2376" "token://$SWARM_TOKEN"

# Map cluster certs to Swarm container.
docker $(docker-machine config ${_master}) run -d \
    --restart="always" \
    --net="bridge" \
    -p "3376:3376" \
    -v "/home/docker/.docker/${_master}:/etc/docker" \
    swarm:latest manage \
        --tlsverify --tlscacert="/etc/docker/ca.pem" \
        --tlscert="/etc/docker/server.pem" --tlskey="/etc/docker/server-key.pem" \
        -H "tcp://0.0.0.0:3376" \
        --strategy spread "token://$SWARM_TOKEN"
#
# Add further nodes.
#
for _nid in {1..1}; do
    _hostid=${_cluster}-${_nid}
    docker-machine create -d virtualbox --virtualbox-boot2docker-url=./boot2docker-1.8.iso \
        --engine-opt="default-network=overlay:multihost" \
        --engine-opt="kv-store=consul:$CONSUL_IP:8500" \
        --engine-label="com.docker.network.driver.overlay.bind_interface=eth1" \
        --engine-label="com.docker.network.driver.overlay.neighbor_ip=$(docker-machine ip ${_master})" \
            ${_hostid}

    # create another swarm process
    docker $(docker-machine config ${_hostid}) run -d \
        --restart="always" \
        --net="bridge" \
            swarm:latest join --addr "$(docker-machine ip ${_hostid}):2376" "token://$SWARM_TOKEN"
    done