swap-setup.rb

require 'fog'

service = Fog::Compute.new(
  provider: 'rackspace',
  rackspace_username: ENV['RAX_USERNAME'],
  rackspace_api_key: ENV['RAX_API_KEY'],
  rackspace_region: :ord
)

# Adjust these settings based on your needs.
@swapsize = "1048576"
@swappiness = "10"

puts "creating server."
server = service.servers.bootstrap :name => 'bootstrap-server',
                            :flavor_id => service.flavors.first.id,
                            :image_id => service.images.find {|img| img.name =~ /Ubuntu/}.id,
                            :public_key_path => '~/.ssh/id_rsa.pub',
                            :private_key_path => '~/.ssh/id_rsa'

puts "server created."

# See:
# http://www.rackspace.com/knowledge_center/article/create-a-linux-swap-file
server.ssh [
  "set -e",
  "dd if=/dev/zero of=/mnt/swapfile bs=1024 count=#{@swapsize}",
  "mkswap /mnt/swapfile",
  "swapon /mnt/swapfile",
  %Q[echo "/mnt/swapfile none swap sw 0 0" >> /etc/fstab],
  %Q[echo "vm.swappiness=#{@swappiness}" >> /etc/sysctl.conf],
  "sysctl vm.swappiness=#{@swappiness}"
  ]

puts "log in with: ssh root@#{server.ipv4_address}"