Example of adding/removing libvirt DHCP host entriy with ruby-libvirt

libvirt.rb

# Example of ruby-libvirt bindings to add a DHCP entry for a particular host
# This updates the dnsmasq config
# Requires ruby-libvirt 0.6.0
require 'libvirt'

conn = Libvirt::open()
network = conn.lookup_network_by_name('default')

xml = %q(<host mac='52:54:00:00:00:01' name='bob' ip='192.168.122.45'/>)
# Add the lease
network.update(
  Libvirt::Network::UPDATE_COMMAND_ADD_LAST,
  Libvirt::Network::SECTION_IP_DHCP_HOST,
  -1,
  xml,
  Libvirt::Network::UPDATE_AFFECT_LIVE | Libvirt::Network::UPDATE_AFFECT_CONFIG
)

# Remove the lease  
network.update(
  Libvirt::Network::UPDATE_COMMAND_DELETE,
  Libvirt::Network::SECTION_IP_DHCP_HOST,
  -1,
  xml,
  Libvirt::Network::UPDATE_AFFECT_LIVE | Libvirt::Network::UPDATE_AFFECT_CONFIG
)