minimal_virt.rb

require 'rubygems'
require 'nokogiri'
require 'json'

minimal = {
	'name' => 'minimal_vm',
	'memory' => 512,
	'hd' => '/var/lib/libvirt/images/fc10-x86-64-xen.img',
	'cdrom' => '/home/bb/os_images/Fedora-10-x86_64-DVD.iso',
	'boot' => ['hd', 'cdrom']
}

defaults = {
  'type' => 'kvm',
	'name' => 'default_vm',
	'memory' => 256,
	'vcpu' => 1,
	'boot' => ['hd'],
	'network' => {
	  'source' => 'default'
	},
	'events' => {
		'poweroff' => 'destroy',
		'reboot' => 'restart',
		'crash' => 'restart'
	},
	'features' => [
	  'acpi',
	  'apic',
	  'pae'
	]
}

def get_next_vnet
  0
end

def hash_to_libvirt_domain(hash)
  root = Nokogiri::XML::Node.new 'domain', Nokogiri::XML::Document.new
  root["type"] = hash["type"]
  
  name_node = Nokogiri::XML::Node.new 'name', Nokogiri::XML::Document.new
  name_node.content = hash["name"]
  root << name_node
  
  memory_node = Nokogiri::XML::Node.new 'memory', Nokogiri::XML::Document.new
  memory_node.content = (hash["memory"] * 1024).to_s
  root << memory_node
  
  vcpu_node = Nokogiri::XML::Node.new 'vcpu', Nokogiri::XML::Document.new
  vcpu_node.content = hash["vcpu"].to_s
  root << vcpu_node
  
  os_node = Nokogiri::XML::Node.new 'os', Nokogiri::XML::Document.new
  type_node = Nokogiri::XML::Node.new 'type', Nokogiri::XML::Document.new
  type_node.content = "hvm"
  os_node << type_node
  
  hash["boot"].each do |boot|
    boot_node = Nokogiri::XML::Node.new 'boot', Nokogiri::XML::Document.new
    boot_node["dev"] = boot
    os_node << boot_node
  end
  root << os_node

  features_node = Nokogiri::XML::Node.new 'features', Nokogiri::XML::Document.new
  hash["features"].each do |feature|
    features_node << Nokogiri::XML::Node.new(feature, Nokogiri::XML::Document.new)
  end
  root << features_node
  
  dev_node = Nokogiri::XML::Node.new 'devices', Nokogiri::XML::Document.new
  hd_node = Nokogiri::XML::Node.new 'disk', Nokogiri::XML::Document.new
  hd_node["device"] = "disk"
  if hash["hd"].match(/^\/dev\//)
    hd_node["type"] = "block"
    
    target_node = Nokogiri::XML::Node.new 'target', Nokogiri::XML::Document.new
    target_node["dev"] = 'hda'; target_node["bus"] = 'ide'
    hd_node << target_node
  else
    hd_node["type"] = "file"
    
    source_node = Nokogiri::XML::Node.new 'source', Nokogiri::XML::Document.new
    source_node["file"] = hash["hd"]
    hd_node << source_node
    
    target_node = Nokogiri::XML::Node.new 'target', Nokogiri::XML::Document.new
    target_node["dev"] = 'vda'; target_node["bus"] = 'virtio'
    hd_node << target_node
  end
  dev_node << hd_node

  if hash.has_key?("cdrom")
    cd_node = Nokogiri::XML::Node.new 'disk', Nokogiri::XML::Document.new
    cd_node["device"] = "cdrom"
    if hash["cdrom"].match(/^\/dev\//)
      cd_node["type"] = "block"
      
      target_node = Nokogiri::XML::Node.new 'target', Nokogiri::XML::Document.new
      target_node["dev"] = 'hdc'; target_node["bus"] = 'ide'
      cd_node << target_node
    else
      cd_node["type"] = "file"
      
      source_node = Nokogiri::XML::Node.new 'source', Nokogiri::XML::Document.new
      source_node["file"] = hash["cdrom"]
      cd_node << source_node
    
      target_node = Nokogiri::XML::Node.new 'target', Nokogiri::XML::Document.new
      target_node["dev"] = 'vdc'; target_node["bus"] = 'virtio'
      cd_node << target_node
    end
    dev_node << cd_node
  end
  
  net_node = Nokogiri::XML::Node.new 'interface', Nokogiri::XML::Document.new
  net_node["type"] = 'network'
  source_node = Nokogiri::XML::Node.new 'source', Nokogiri::XML::Document.new
  source_node["network"] = hash["network"]["source"]
  net_node << source_node
  
  #target_node = Nokogiri::XML::Node.new 'target', Nokogiri::XML::Document.new
  #target_node["dev"] = (hash["network"].has_key?("target") ? hash["network"]["target"] : "vnet {get_next_vnet}")
  #net_node << target_node
  dev_node << net_node
  
  #<serial type='pty'>
  #  <source path='/dev/pts/3'/>
  #  <target port='0'/>
  #</serial>
  serial_node = Nokogiri::XML::Node.new 'serial', Nokogiri::XML::Document.new
  serial_node["type"] = 'pty'
  #source_node = Nokogiri::XML::Node.new 'source', Nokogiri::XML::Document.new
  #source_node["path"] = '/dev/pts/3'
  #serial_node << source_node
  dev_node << serial_node
  
  #<console type='pty' tty='/dev/pts/3'>
  #  <source path='/dev/pts/3'/>
  #  <target port='0'/>
  #</console>
  
  #<input type='mouse' bus='ps2'/>
  input_node = Nokogiri::XML::Node.new 'input', Nokogiri::XML::Document.new
  input_node["type"] = 'mouse'; input_node["bus"] = 'ps2'
  dev_node << input_node
  
  #<graphics type='vnc' port='5908' autoport='yes' keymap='en-us'/>
  graphics_node = Nokogiri::XML::Node.new 'graphics', Nokogiri::XML::Document.new
  graphics_node["type"] = 'vnc'; graphics_node["autoport"] = 'yes'
  dev_node << graphics_node
  
  root << dev_node
  
  Nokogiri::XML::Document.new << root
end

def hash_to_libvirt(type, hash)
  case type
  when 'domain', 'network', 'pool', 'volume'
    send("hash_to_libvirt_#{type}", hash)
  else
    raise "Unknown type #{type}"
  end
end

puts hash_to_libvirt("domain", defaults.merge(minimal))