Merge lp:~rvb/maas/rev-zone-generation-ipv6 into lp:~maas-committers/maas/trunk

[Raphaël Badin]

Make DNSReverseZoneConfig.compose_zone_name capable of generating reverse zone file names for IPv6 networks.

[Blake Rouse (blake-rouse)]

Approved.

The naming of variable "rest" is a little weird. I assume you are meaning the rest of the reverse_dns? Having an issue with coming up with a better name. Maybe "rest_limit", don't know if that is any better. :)

review: Approve

[Raphaël Badin (rvb)]

review: Approve

=== modified file 'src/provisioningserver/dns/config.py'
--- src/provisioningserver/dns/config.py	2014-06-10 14:45:14 +0000
+++ src/provisioningserver/dns/config.py	2014-06-25 09:35:41 +0000
@@ -31,10 +31,12 @@
     imap,
     islice,
     )
+import math
 import os.path
 import re
 
 from celery.app import app_or_default
+from netaddr import IPAddress
 from provisioningserver.dns.utils import generated_hostname
 from provisioningserver.utils import (
     atomic_write,
@@ -411,9 +413,25 @@
     @classmethod
     def compose_zone_name(cls, network):
         """Return the name of the reverse zone."""
-        broadcast, netmask = network.broadcast, network.netmask
-        octets = broadcast.words[:netmask.words.count(255)]
-        return '%s.in-addr.arpa' % '.'.join(imap(unicode, reversed(octets)))
+        # Generate the name of the reverse zone file:
+        # Use netaddr's reverse_dns() to get the reverse IP name
+        # of the first IP address in the network and then drop the first
+        # octets of that name (i.e. drop the octets that will be specified in
+        # the zone file).
+        first = IPAddress(network.first)
+        if first.version == 6:
+            # IPv6.
+            # Use float division and ceil to cope with network sizes that
+            # are not divisible by 4.
+            rest_limit = int(math.ceil((128 - network.prefixlen) / 4.))
+        else:
+            # IPv4.
+            # Use float division and ceil to cope with splits not done on
+            # octets boundaries.
+            rest_limit = int(math.ceil((32 - network.prefixlen) / 8.))
+        reverse_name = first.reverse_dns.split('.', rest_limit)[-1]
+        # Strip off trailing '.'.
+        return reverse_name[:-1]
 
     @classmethod
     def shortened_reversed_ip(cls, ip, num_bytes):

=== modified file 'src/provisioningserver/dns/tests/test_config.py'
--- src/provisioningserver/dns/tests/test_config.py	2014-01-22 05:45:16 +0000
+++ src/provisioningserver/dns/tests/test_config.py	2014-06-25 09:35:41 +0000
@@ -547,25 +547,36 @@
             os.path.join(conf.DNS_CONFIG_DIR, reverse_file_name),
             dns_zone_config.target_path)
 
-    def test_reverse_data_slash_24(self):
-        # DNSReverseZoneConfig calculates the reverse data correctly for
-        # a /24 network.
-        domain = factory.make_name('zone')
-        network = IPNetwork('192.168.0.1/24')
-        dns_zone_config = DNSReverseZoneConfig(domain, network=network)
-        self.assertEqual(
-            '0.168.192.in-addr.arpa',
-            dns_zone_config.zone_name)
+    def test_reverse_zone_file(self):
+        # DNSReverseZoneConfig calculates the reverse zone file name
+        # correctly for IPv4 and IPv6 networks.
+        expected = [
+            # IPv4 networks.
+            (IPNetwork('192.168.0.1/22'), '168.192.in-addr.arpa'),
+            (IPNetwork('192.168.0.1/24'), '0.168.192.in-addr.arpa'),
+            # IPv6 networks.
+            (IPNetwork('3ffe:801::/32'), '1.0.8.0.e.f.f.3.ip6.arpa'),
+            (IPNetwork('2001:db8:0::/48'), '0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa'),
+            (
+                IPNetwork('2001:ba8:1f1:400::/56'),
+                '4.0.1.f.1.0.8.a.b.0.1.0.0.2.ip6.arpa'
+            ),
+            (
+                IPNetwork('2610:8:6800:1::/64'),
+                '1.0.0.0.0.0.8.6.8.0.0.0.0.1.6.2.ip6.arpa',
+            ),
+            (
+                IPNetwork('2001:ba8:1f1:400::/103'),
+                '0.0.0.0.0.0.0.0.0.0.0.4.0.1.f.1.0.8.a.b.0.1.0.0.2.ip6.arpa',
+            ),
 
-    def test_reverse_data_slash_22(self):
-        # DNSReverseZoneConfig calculates the reverse data correctly for
-        # a /22 network.
-        domain = factory.getRandomString()
-        network = IPNetwork('192.168.0.1/22')
-        dns_zone_config = DNSReverseZoneConfig(domain, network=network)
-        self.assertEqual(
-            '168.192.in-addr.arpa',
-            dns_zone_config.zone_name)
+        ]
+        results = []
+        for network, _ in expected:
+            domain = factory.make_name('zone')
+            dns_zone_config = DNSReverseZoneConfig(domain, network=network)
+            results.append((network, dns_zone_config.zone_name))
+        self.assertEqual(expected, results)
 
     def test_get_static_mapping_returns_iterator(self):
         self.assertThat(