net: fix subnet_is_ipv6() for stateless|stateful

Function return false for ipv6_dhcpv6-stateless|stateful,
the eni renderer does not add '6' to 'inet' which is
incorrect.

The subnet_is_ipv6() function is updated to also return
true if startswith('ipv6').

LP: #1848690

2 files changed, 18 insertions, 2 deletions

diff --git a/cloudinit/net/network_state.py b/cloudinit/net/network_state.py
index b485f3d9..ba85c69e 100644
--- a/cloudinit/net/network_state.py
+++ b/cloudinit/net/network_state.py
@@ -919,8 +919,8 @@ def is_ipv6_addr(address):
 
 def subnet_is_ipv6(subnet):
     """Common helper for checking network_state subnets for ipv6."""
-    # 'static6' or 'dhcp6'
-    if subnet['type'].endswith('6'):
+    # 'static6', 'dhcp6', 'ipv6_dhcpv6-stateful' or 'ipv6_dhcpv6-stateless'
+    if subnet['type'].endswith('6') or subnet['type'].startswith('ipv6'):
         # This is a request for DHCPv6.
         return True
     elif subnet['type'] == 'static' and is_ipv6_addr(subnet.get('address')):
diff --git a/tests/unittests/test_net.py b/tests/unittests/test_net.py
index 21604b12..6f83ad73 100644
--- a/tests/unittests/test_net.py
+++ b/tests/unittests/test_net.py
@@ -4098,6 +4098,22 @@ class TestEniRoundTrip(CiTestCase):
             entry['expected_eni'].splitlines(),
             files['/etc/network/interfaces'].splitlines())
 
+    def testsimple_render_dhcpv6_stateless(self):
+        entry = NETWORK_CONFIGS['dhcpv6_stateless']
+        files = self._render_and_read(network_config=yaml.load(
+            entry['yaml']))
+        self.assertEqual(
+            entry['expected_eni'].splitlines(),
+            files['/etc/network/interfaces'].splitlines())
+
+    def testsimple_render_dhcpv6_stateful(self):
+        entry = NETWORK_CONFIGS['dhcpv6_stateless']
+        files = self._render_and_read(network_config=yaml.load(
+            entry['yaml']))
+        self.assertEqual(
+            entry['expected_eni'].splitlines(),
+            files['/etc/network/interfaces'].splitlines())
+
     def testsimple_render_manual(self):
         """Test rendering of 'manual' for 'type' and 'control'.