Make nova-dhcpbridge output lease information in dnsmasq's leasesfile format.

2 files changed, 56 insertions, 2 deletions

diff --git a/nova/network/linux_net.py b/nova/network/linux_net.py
index e69ed2f75..7106e6164 100644
--- a/nova/network/linux_net.py
+++ b/nova/network/linux_net.py
@@ -19,6 +19,7 @@ Implements vlans, bridges, and iptables rules using linux utilities.
 
 import inspect
 import os
+import calendar
 
 from eventlet import semaphore
 
@@ -56,6 +57,8 @@ flags.DEFINE_string('routing_source_ip', '$my_ip',
                     'Public IP of network host')
 flags.DEFINE_string('input_chain', 'INPUT',
                     'chain to add nova_input to')
+flags.DEFINE_integer('dhcp_lease_time', 120,
+                     'Lifetime of a DHCP lease')
 
 flags.DEFINE_string('dns_server', None,
                     'if set, uses specific dns server for dnsmasq')
@@ -533,8 +536,17 @@ def ensure_bridge(bridge, interface, net_attrs=None):
                                              bridge)
 
 
+def get_dhcp_leases(context, network_id):
+    """Return a network's hosts config in dnsmasq leasefile format"""
+    hosts = []
+    for fixed_ip_ref in db.network_get_associated_fixed_ips(context,
+                                                            network_id):
+        hosts.append(_host_lease(fixed_ip_ref))
+    return '\n'.join(hosts)
+
+
 def get_dhcp_hosts(context, network_id):
-    """Get a string containing a network's hosts config in dnsmasq format"""
+    """Get a string containing a network's hosts config in dhcp-host format"""
     hosts = []
     for fixed_ip_ref in db.network_get_associated_fixed_ips(context,
                                                             network_id):
@@ -625,8 +637,24 @@ interface %s
                        utils.get_my_linklocal(network_ref['bridge'])})
 
 
+def _host_lease(fixed_ip_ref):
+    """Return a host string for an address in leasefile format"""
+    instance_ref = fixed_ip_ref['instance']
+    if instance_ref['updated_at']:
+        timestamp = instance_ref['updated_at']
+    else:
+        timestamp = instance_ref['created_at']
+
+    seconds_since_epoch = calendar.timegm(timestamp.utctimetuple())
+
+    return "%d %s %s %s *" % (seconds_since_epoch + FLAGS.dhcp_lease_time,
+                              instance_ref['mac_address'],
+                              fixed_ip_ref['address'],
+                              instance_ref['hostname'] or '*')
+
+
 def _host_dhcp(fixed_ip_ref):
-    """Return a host string for an address"""
+    """Return a host string for an address in dhcp-host format"""
     instance_ref = fixed_ip_ref['instance']
     return "%s,%s.%s,%s" % (instance_ref['mac_address'],
                                    instance_ref['hostname'],
diff --git a/nova/tests/test_network.py b/nova/tests/test_network.py
index 53e35ce7e..1e634b388 100644
--- a/nova/tests/test_network.py
+++ b/nova/tests/test_network.py
@@ -20,6 +20,7 @@ Unit Tests for network code
 """
 import IPy
 import os
+import time
 
 from nova import context
 from nova import db
@@ -463,6 +464,31 @@ class NetworkTestCase(test.TestCase):
                                                   network['id'])
         self.assertEqual(ip_count, num_available_ips)
 
+    def test_dhcp_lease_output(self):
+        admin_ctxt = context.get_admin_context()
+        address = self._create_address(0, self.instance_id)
+        lease_ip(address)
+        network_ref = db.network_get_by_instance(admin_ctxt, self.instance_id)
+        leases = linux_net.get_dhcp_leases(context.get_admin_context(),
+                                           network_ref['id'])
+        for line in leases.split('\n'):
+            seconds, mac, ip, hostname, client_id = line.split(' ')
+            self.assertTrue(int(seconds) > time.time(), 'Lease expires in '
+                                                        'the past')
+            octets = mac.split(':')
+            self.assertEqual(len(octets), 6, "Wrong number of octets "
+                                             "in %s" % (max,))
+            for octet in octets:
+                self.assertEqual(len(octet), 2, "Oddly sized octet: %s"
+                                                                    % (octet,))
+                # This will throw an exception if the octet is invalid
+                int(octet, 16)
+
+            # And this will raise an exception in case of an invalid IP
+            IPy.IP(ip)
+
+        release_ip(address)
+
 
 def is_allocated_in_project(address, project_id):
     """Returns true if address is in specified project"""