Merge "Dnsmasq uses all agent IPs as nameservers"

neutron/agent/linux/dhcp.py

@@ -16,6 +16,7 @@
 #    under the License.
 
 import abc
+import collections
 import os
 import re
 import shutil
@@ -459,6 +460,9 @@ class Dnsmasq(DhcpLocalProcess):
             subnet_to_interface_ip = self._make_subnet_interface_ip_map()
 
         options = []
+
+        dhcp_ips = collections.defaultdict(list)
+        subnet_idx_map = {}
         for i, subnet in enumerate(self.network.subnets):
             if not subnet.enable_dhcp:
                 continue
@@ -466,6 +470,10 @@ class Dnsmasq(DhcpLocalProcess):
                 options.append(
                     self._format_option(i, 'dns-server',
                                         ','.join(subnet.dns_nameservers)))
+            else:
+                # use the dnsmasq ip as nameservers only if there is no
+                # dns-server submitted by the server
+                subnet_idx_map[subnet.id] = i
 
             gateway = subnet.gateway_ip
             host_routes = []
@@ -503,6 +511,22 @@ class Dnsmasq(DhcpLocalProcess):
                     self._format_option(port.id, opt.opt_name, opt.opt_value)
                     for opt in port.extra_dhcp_opts)
 
+            # provides all dnsmasq ip as dns-server if there is more than
+            # one dnsmasq for a subnet and there is no dns-server submitted
+            # by the server
+            if port.device_owner == 'network:dhcp':
+                for ip in port.fixed_ips:
+                    i = subnet_idx_map.get(ip.subnet_id)
+                    if i is None:
+                        continue
+                    dhcp_ips[i].append(ip.ip_address)
+
+        for i, ips in dhcp_ips.items():
+            if len(ips) > 1:
+                options.append(self._format_option(i,
+                                                   'dns-server',
+                                                   ','.join(ips)))
+
         name = self.get_conf_file_name('opts')
         utils.replace_file(name, '\n'.join(options))
         return name

neutron/tests/unit/test_linux_dhcp.py

@@ -89,6 +89,30 @@ class FakeRouterPort:
         self.extra_dhcp_opts = []
 
 
+class FakePortMultipleAgents1:
+    id = 'rrrrrrrr-rrrr-rrrr-rrrr-rrrrrrrrrrrr'
+    admin_state_up = True
+    device_owner = 'network:dhcp'
+    fixed_ips = [FakeIPAllocation('192.168.0.5',
+                                  'dddddddd-dddd-dddd-dddd-dddddddddddd')]
+    mac_address = '00:00:0f:dd:dd:dd'
+
+    def __init__(self):
+        self.extra_dhcp_opts = []
+
+
+class FakePortMultipleAgents2:
+    id = 'aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa'
+    admin_state_up = True
+    device_owner = 'network:dhcp'
+    fixed_ips = [FakeIPAllocation('192.168.0.6',
+                                  'dddddddd-dddd-dddd-dddd-dddddddddddd')]
+    mac_address = '00:00:0f:ee:ee:ee'
+
+    def __init__(self):
+        self.extra_dhcp_opts = []
+
+
 class FakeV4HostRoute:
     destination = '20.0.0.1/24'
     nexthop = '20.0.0.1'
@@ -124,6 +148,42 @@ class FakeV4SubnetGatewayRoute:
     dns_nameservers = ['8.8.8.8']
 
 
+class FakeV4SubnetMultipleAgentsWithoutDnsProvided:
+    id = 'dddddddd-dddd-dddd-dddd-dddddddddddd'
+    ip_version = 4
+    cidr = '192.168.0.0/24'
+    gateway_ip = '192.168.0.1'
+    enable_dhcp = True
+    dns_nameservers = []
+    host_routes = []
+
+
+class FakeV4MultipleAgentsWithoutDnsProvided:
+    id = 'ffffffff-ffff-ffff-ffff-ffffffffffff'
+    subnets = [FakeV4SubnetMultipleAgentsWithoutDnsProvided()]
+    ports = [FakePort1(), FakePort2(), FakePort3(), FakeRouterPort(),
+             FakePortMultipleAgents1(), FakePortMultipleAgents2()]
+    namespace = 'qdhcp-ns'
+
+
+class FakeV4SubnetMultipleAgentsWithDnsProvided:
+    id = 'dddddddd-dddd-dddd-dddd-dddddddddddd'
+    ip_version = 4
+    cidr = '192.168.0.0/24'
+    gateway_ip = '192.168.0.1'
+    enable_dhcp = True
+    dns_nameservers = ['8.8.8.8']
+    host_routes = []
+
+
+class FakeV4MultipleAgentsWithDnsProvided:
+    id = 'ffffffff-ffff-ffff-ffff-ffffffffffff'
+    subnets = [FakeV4SubnetMultipleAgentsWithDnsProvided()]
+    ports = [FakePort1(), FakePort2(), FakePort3(), FakeRouterPort(),
+             FakePortMultipleAgents1(), FakePortMultipleAgents2()]
+    namespace = 'qdhcp-ns'
+
+
 class FakeV6Subnet:
     id = 'ffffffff-ffff-ffff-ffff-ffffffffffff'
     ip_version = 6
@@ -710,6 +770,30 @@ tag:tag1,249,%s,%s""".lstrip() % (fake_v6,
 
         self.safe.assert_called_once_with('/foo/opts', expected)
 
+    def test_output_opts_file_multiple_agents_without_dns_provided(self):
+        expected = """
+tag:tag0,option:router,192.168.0.1
+tag:tag0,option:dns-server,192.168.0.5,192.168.0.6""".lstrip()
+        with mock.patch.object(dhcp.Dnsmasq, 'get_conf_file_name') as conf_fn:
+            conf_fn.return_value = '/foo/opts'
+            dm = dhcp.Dnsmasq(self.conf,
+                              FakeV4MultipleAgentsWithoutDnsProvided(),
+                              version=float(2.59))
+            dm._output_opts_file()
+        self.safe.assert_called_once_with('/foo/opts', expected)
+
+    def test_output_opts_file_multiple_agents_with_dns_provided(self):
+        expected = """
+tag:tag0,option:dns-server,8.8.8.8
+tag:tag0,option:router,192.168.0.1""".lstrip()
+        with mock.patch.object(dhcp.Dnsmasq, 'get_conf_file_name') as conf_fn:
+            conf_fn.return_value = '/foo/opts'
+            dm = dhcp.Dnsmasq(self.conf,
+                              FakeV4MultipleAgentsWithDnsProvided(),
+                              version=float(2.59))
+            dm._output_opts_file()
+        self.safe.assert_called_once_with('/foo/opts', expected)
+
     def test_output_opts_file_single_dhcp(self):
         expected = """
 tag:tag0,option:dns-server,8.8.8.8