def _output_opts_file(self):
"""Write a dnsmasq compatible options file."""
options, subnet_index_map = self._generate_opts_per_subnet()
options += self._generate_opts_per_port(subnet_index_map)
name = self.get_conf_file_name('opts')
utils.replace_file(name, '\n'.join(options))
return name
def _output_hosts_file(self):
"""Writes a dnsmasq compatible dhcp hosts file.
The generated file is sent to the --dhcp-hostsfile option of dnsmasq,
and lists the hosts on the network which should receive a dhcp lease.
Each line in this file is in the form::
'mac_address,FQDN,ip_address'
IMPORTANT NOTE: a dnsmasq instance does not resolve hosts defined in
this file if it did not give a lease to a host listed in it (e.g.:
multiple dnsmasq instances on the same network if this network is on
multiple network nodes). This file is only defining hosts which
should receive a dhcp lease, the hosts resolution in itself is
defined by the `_output_addn_hosts_file` method.
"""
buf = six.StringIO()
filename = self.get_conf_file_name('host')
LOG.debug('Building host file: %s', filename)
dhcp_enabled_subnet_ids = [s.id for s in self.network.subnets
if s.enable_dhcp]
# NOTE(ihrachyshka): the loop should not log anything inside it, to
# avoid potential performance drop when lots of hosts are dumped
for host_tuple in self._iter_hosts():
port, alloc, hostname, name, no_dhcp, no_opts = host_tuple
if port.device_owner == 'network:dhcp':
continue
if no_dhcp:
if not no_opts and getattr(port, 'extra_dhcp_opts', False):
buf.write('%s,%s%s\n' %
(port.mac_address, 'set:', port.id))
continue
# don't write ip address which belongs to a dhcp disabled subnet.
if alloc.subnet_id not in dhcp_enabled_subnet_ids:
continue
ip_address = self._format_address_for_dnsmasq(alloc.ip_address)
if getattr(port, 'extra_dhcp_opts', False):
buf.write('%s,%s,%s,%s%s\n' %
(port.mac_address, name, ip_address,
'set:', port.id))
else:
buf.write('%s,%s,%s\n' %
(port.mac_address, name, ip_address))
utils.replace_file(filename, buf.getvalue())
LOG.debug('Done building host file %s', filename)
return filename
def _output_init_lease_file(self):
"""Write a fake lease file to bootstrap dnsmasq.
The generated file is passed to the --dhcp-leasefile option of dnsmasq.
This is used as a bootstrapping mechanism to avoid NAKing active leases
when a dhcp server is scheduled to another agent. Using a leasefile
will also prevent dnsmasq from NAKing or ignoring renewals after a
restart.
Format is as follows:
epoch-timestamp mac_addr ip_addr hostname client-ID
"""
filename = self.get_conf_file_name('leases')
buf = six.StringIO()
LOG.debug('Building initial lease file: %s', filename)
# we make up a lease time for the database entry
if self.conf.dhcp_lease_duration == -1:
# Even with an infinite lease, a client may choose to renew a
# previous lease on reboot or interface bounce so we should have
# an entry for it.
# Dnsmasq timestamp format for an infinite lease is is 0.
timestamp = 0
else:
timestamp = int(time.time()) + self.conf.dhcp_lease_duration
dhcp_enabled_subnet_ids = [s.id for s in self.network.subnets
if s.enable_dhcp]
for host_tuple in self._iter_hosts():
port, alloc, hostname, name, no_dhcp, no_opts = host_tuple
# don't write ip address which belongs to a dhcp disabled subnet
# or an IPv6 SLAAC/stateless subnet
if port.device_owner == 'network:dhcp':
continue
if no_dhcp or alloc.subnet_id not in dhcp_enabled_subnet_ids:
continue
ip_address = self._format_address_for_dnsmasq(alloc.ip_address)
# all that matters is the mac address and IP. the hostname and
# client ID will be overwritten on the next renewal.
buf.write('%s %s %s * *\n' %
(timestamp, port.mac_address, ip_address))
contents = buf.getvalue()
utils.replace_file(filename, contents)
LOG.debug('Done building initial lease file %s with contents:\n%s',
filename, contents)
return filename
def _output_addn_hosts_file(self):
"""Writes a dnsmasq compatible additional hosts file.
The generated file is sent to the --addn-hosts option of dnsmasq,
and lists the hosts on the network which should be resolved even if
the dnsmaq instance did not give a lease to the host (see the
`_output_hosts_file` method).
Each line in this file is in the same form as a standard /etc/hosts
file.
"""
buf = six.StringIO()
for host_tuple in self._iter_hosts():
port, alloc, hostname, fqdn, no_dhcp, no_opts = host_tuple
# It is compulsory to write the `fqdn` before the `hostname` in
# order to obtain it in PTR responses.
if alloc:
buf.write('%s\t%s %s\n' % (alloc.ip_address, fqdn, hostname))
addn_hosts = self.get_conf_file_name('addn_hosts')
utils.replace_file(addn_hosts, buf.getvalue())
return addn_hosts
def interface_name(self, value):
interface_file_path = self.get_conf_file_name('interface')
utils.replace_file(interface_file_path, value)