Vagrant+CoreOSでdocker-composeをプロビジョニングする ref: http://qiita.com/y_hokkey/items/c9a740b3f3d800abdb67
...
(1..$num_instances).each do |i|
...
# docker-composeのインストール
$get_compose = <<-'EOF'
curl -L https://github.com/docker/compose/releases/download/1.2.0/docker-compose-`uname -s`-`uname -m` > ~/docker-compose
sudo mkdir /opt
sudo mkdir /opt/bin
sudo mv ~/docker-compose /opt/bin/docker-compose
sudo chown root:root /opt/bin/docker-compose
sudo chmod +x /opt/bin/docker-compose
EOF
config.vm.provision :shell, :inline => $get_compose