vagrant: add ability to use drives in the VMs

When testing deployments of SDS, it is quite useful to get a Kubernetes
env with nodes having dedicated drives.
You can now enable this by setting: kube_node_instances_with_disks: true

Also you can chose the amount of drives per machine and their respective
size:

* kube_node_instances_with_disks_number: 10
* kube_node_instances_with_disks_size: "20G"

Signed-off-by: Sébastien Han <seb@redhat.com>

Vagrantfile

@@ -9,6 +9,9 @@ CONFIG = File.join(File.dirname(__FILE__), "vagrant/config.rb")
 
 COREOS_URL_TEMPLATE = "https://storage.googleapis.com/%s.release.core-os.net/amd64-usr/current/coreos_production_vagrant.json"
 
+# Uniq disk UUID for libvirt
+DISK_UUID = Time.now.utc.to_i
+
 SUPPORTED_OS = {
   "coreos-stable" => {box: "coreos-stable",      bootstrap_os: "coreos", user: "core", box_url: COREOS_URL_TEMPLATE % ["stable"]},
   "coreos-alpha"  => {box: "coreos-alpha",       bootstrap_os: "coreos", user: "core", box_url: COREOS_URL_TEMPLATE % ["alpha"]},
@@ -34,6 +37,11 @@ $etcd_instances = $num_instances
 $kube_master_instances = $num_instances == 1 ? $num_instances : ($num_instances - 1)
 # All nodes are kube nodes
 $kube_node_instances = $num_instances
+# The following only works when using the libvirt provider
+$kube_node_instances_with_disks = false
+$kube_node_instances_with_disks_size = "20G"
+$kube_node_instances_with_disks_number = 2
+
 $local_release_dir = "/vagrant/temp"
 
 host_vars = {}
@@ -132,6 +140,18 @@ Vagrant.configure("2") do |config|
       # Disable swap for each vm
       config.vm.provision "shell", inline: "swapoff -a"
 
+      if $kube_node_instances_with_disks
+        # Libvirt
+        driverletters = ('a'..'z').to_a
+        config.vm.provider :libvirt do |lv|
+          # always make /dev/sd{a/b/c} so that CI can ensure that
+          # virtualbox and libvirt will have the same devices to use for OSDs
+          (1..$kube_node_instances_with_disks_number).each do |d|
+            lv.storage :file, :device => "hd#{driverletters[d]}", :path => "disk-#{i}-#{d}-#{DISK_UUID}.disk", :size => $kube_node_instances_with_disks_size, :bus => "ide"
+          end
+        end
+      end
+
       # Only execute once the Ansible provisioner,
       # when all the machines are up and ready.
       if i == $num_instances