Create a cluster of Docker Engines, a.k.a a swarm

swarm.sh

#!/bin/sh

###
## Virtual box options
###
export VIRTUALBOX_CPU_COUNT='1'
export VIRTUALBOX_DISK_SIZE='10000'
export VIRTUALBOX_MEMORY_SIZE='512'

swarm_workers=2

###
## SWARM MANAGER
###
echo
echo "############################" 
echo "## Creating swarm manager ##"
echo "############################" 
echo 
docker-machine create -d virtualbox swarm-manager; manager_ip=$(docker-machine ip swarm-manager)

echo 
echo " #### IP: ${manager_ip}"

# Init swarm
docker-machine ssh swarm-manager "docker swarm init --advertise-addr $manager_ip | tee /tmp/output"
wait $!

swarm_join_command=`docker-machine ssh swarm-manager cat /tmp/output | grep '^    ' | tr -d '\n' | sed 's/[\]    //g'`;

###
## SWARM WORKERS
###

echo
echo "############################" 
echo "## Creating swarm workers ##"
echo "############################" 
for i in `seq 1 $swarm_workers`;
do
    echo
    echo "  ## Creating swarm-worker-${i} and joining swarm-manager"
    echo
    docker-machine create -d virtualbox swarm-worker-${i}; docker-machine ssh swarm-worker-${i} "${swarm_join_command}"
done