From http://niccloud.niandc.ne.jp/?p=749&preview=1&_ppp=e743ff0486

Vagrantfile-Softlayer

# -*- mode: ruby -*-
# vi: set ft=ruby :

# Vagrantfile API/syntax version. Don't touch unless you know what you're doing!
VAGRANTFILE_API_VERSION = "2"

Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
    config.vm.box = "dummy"
    config.vm.box_url = "https://github.com/audiolize/vagrant-softlayer/raw/master/dummy.box"
    config.vm.synced_folder ".", "/vagrant", type: "rsync"
    config.ssh.private_key_path = "/Users/tokida/.ssh/sl_rsa"
    config.ssh.username = "root"

    config.vm.provider :softlayer do | sl, override |
            sl.api_key = "*****"
            sl.username = "SL****"
            sl.datacenter   = "ams01"
            sl.dedicated    = false
            sl.domain       = "niandc.co.jp"
            sl.disk_capacity = { 0 => 25 }
            sl.hostname     = "vagrant01"
            sl.hourly_billing = true
            sl.image_guid   = nil
            sl.local_disk   = true
            sl.max_memory   = 1024
            sl.network_speed = 10
            sl.operating_system = "UBUNTU_LATEST"
            sl.ssh_key = [“tokida”]
            sl.start_cpus   = 1

            override.ssh.username = "root"
    end

end