Fix inspector ip range for dhcpv6-stateless

When using dhcpv6-stateless a range should not be
used. According to dnsmasq manual page:

  A static-only subnet with address all zeros may be
  used as a "catch-all" address to enable replies to
  all Information-request packets on a subnet which
  is provided with stateless DHCPv6, ie
  --dhcp-range=::,static

Closes-Bug: #1853334
Change-Id: I6627da48bc170f7ecccaf84c0fccda9e2edd5af3

releasenotes/notes/fix-dhcpv6-stateless-inspector-dnsmasq-range-9d0f4635ecce3d2f.yaml

@@ -0,0 +1,8 @@
+---
+fixes:
+  - |
+    Fixed an issue where the DHCP server for ironic-inspector was configured to
+    operate in DHCPv6-stateful mode when the undercloud configuration specified
+    DHCPv6-stateless mode. (See bug: `1853334
+    <https://bugs.launchpad.net/tripleo/+bug/1853334>`_)
+

tripleoclient/tests/v1/undercloud/test_config.py

@@ -185,7 +185,7 @@ class TestNetworkSettings(base.TestCase):
         }
         self.assertEqual(expected, env)
 
-    def test_ipv6_control_plane(self):
+    def test_ipv6_control_plane_stateless_default(self):
         env = {}
         self.conf.config(local_ip='fd12:3456:789a:1::2/64',
                          undercloud_admin_host='fd12:3456:789a:1::3',
@@ -203,6 +203,55 @@ class TestNetworkSettings(base.TestCase):
                          host_routes=[],
                          group='ctlplane-subnet')
         undercloud_config._process_network_args(env)
+        expected = {
+            'NovaIPv6': True,
+            'RabbitIPv6': True,
+            'MemcachedIPv6': True,
+            'RedisIPv6': True,
+            'MysqlIPv6': True,
+            'IronicIpVersion': '6',
+            'ControlPlaneStaticRoutes': [],
+            'IronicInspectorSubnets': [
+                {'gateway': 'fd12:3456:789a:1::1',
+                 'host_routes': [],
+                 'ip_range': 'fd12:3456:789a:1::,static',
+                 'netmask': 'ffff:ffff:ffff:ffff::',
+                 'tag': 'ctlplane-subnet',
+                 'mtu': 1500}],
+            'MasqueradeNetworks': {},
+            'UndercloudCtlplaneSubnets': {
+                'ctlplane-subnet': {
+                    'AllocationPools': [
+                        {'start': 'fd12:3456:789a:1::10',
+                         'end': 'fd12:3456:789a:1::20'}],
+                    'DnsNameServers': ['fd12:3456:789a:1::5',
+                                       'fd12:3456:789a:1::6'],
+                    'HostRoutes': [],
+                    'NetworkCidr': 'fd12:3456:789a:1::/64',
+                    'NetworkGateway': 'fd12:3456:789a:1::1'}},
+            'UndercloudCtlplaneIPv6AddressMode': 'dhcpv6-stateless',
+        }
+        self.assertEqual(expected, env)
+
+    def test_ipv6_control_plane_stateful(self):
+        env = {}
+        self.conf.config(local_ip='fd12:3456:789a:1::2/64',
+                         undercloud_admin_host='fd12:3456:789a:1::3',
+                         undercloud_public_host='fd12:3456:789a:1::4',
+                         ipv6_address_mode='dhcpv6-stateful')
+        self.conf.config(cidr='fd12:3456:789a:1::/64',
+                         dhcp_start='fd12:3456:789a:1::10',
+                         dhcp_end='fd12:3456:789a:1::20',
+                         dhcp_exclude=[],
+                         dns_nameservers=['fd12:3456:789a:1::5',
+                                          'fd12:3456:789a:1::6'],
+                         inspection_iprange=('fd12:3456:789a:1::30,'
+                                             'fd12:3456:789a:1::40'),
+                         gateway='fd12:3456:789a:1::1',
+                         masquerade=False,
+                         host_routes=[],
+                         group='ctlplane-subnet')
+        undercloud_config._process_network_args(env)
         expected = {
             'NovaIPv6': True,
             'RabbitIPv6': True,
@@ -229,7 +278,7 @@ class TestNetworkSettings(base.TestCase):
                     'HostRoutes': [],
                     'NetworkCidr': 'fd12:3456:789a:1::/64',
                     'NetworkGateway': 'fd12:3456:789a:1::1'}},
-            'UndercloudCtlplaneIPv6AddressMode': 'dhcpv6-stateless',
+            'UndercloudCtlplaneIPv6AddressMode': 'dhcpv6-stateful',
         }
         self.assertEqual(expected, env)
 

tripleoclient/v1/undercloud_config.py

@@ -224,7 +224,18 @@ def _generate_inspection_subnets():
         env_dict = {}
         s = CONF.get(subnet)
         env_dict['tag'] = subnet
-        env_dict['ip_range'] = s.inspection_iprange
+        if netaddr.IPNetwork(s.cidr).version == 4:
+            env_dict['ip_range'] = s.inspection_iprange
+        if netaddr.IPNetwork(s.cidr).version == 6:
+            if CONF['ipv6_address_mode'] == 'dhcpv6-stateful':
+                env_dict['ip_range'] = s.inspection_iprange
+            if CONF['ipv6_address_mode'] == 'dhcpv6-stateless':
+                # dnsmasq(8): A static-only subnet with address all zeros may
+                # be used as a "catch-all" address to enable replies to all
+                # Information-request packets on a subnet which is provided
+                # with stateless DHCPv6, ie --dhcp-range=::,static
+                env_dict['ip_range'] = ','.join(
+                    [str(netaddr.IPNetwork(s.cidr).ip), 'static'])
         env_dict['netmask'] = str(netaddr.IPNetwork(s.cidr).netmask)
         env_dict['gateway'] = s.gateway
         env_dict['host_routes'] = s.host_routes