net: Fix static routes to host in eni renderer

cloudinit/net/eni.py

@@ -387,6 +387,8 @@ def _render_route(self, route, indent=""):
                 if k == 'network':
                     if ':' in route[k]:
                         route_line += ' -A inet6'
+                    elif route.get('prefix') == 32:
+                        route_line += ' -host'
                     else:
                         route_line += ' -net'
                     if 'prefix' in route:

tests/integration_tests/bugs/test_gh668.py

@@ -0,0 +1,37 @@
+"""Integration test for gh-668.
+
+Ensure that static route to host is working correctly.
+The original problem is specific to the ENI renderer but that test is suitable
+for all network configuration outputs.
+"""
+
+import pytest
+
+from tests.integration_tests.instances import IntegrationInstance
+
+
+DESTINATION_IP = "172.16.0.10"
+GATEWAY_IP = "10.0.0.100"
+
+NETWORK_CONFIG = """\
+version: 2
+ethernets:
+  eth0:
+    addresses: [10.0.0.10/8]
+    dhcp4: false
+    routes:
+    - to: {}/32
+      via: {}
+""".format(DESTINATION_IP, GATEWAY_IP)
+
+EXPECTED_ROUTE = "{} via {}".format(DESTINATION_IP, GATEWAY_IP)
+
+
+@pytest.mark.lxd_container
+@pytest.mark.lxd_vm
+@pytest.mark.lxd_config_dict({
+    "user.network-config": NETWORK_CONFIG,
+})
+def test_static_route_to_host(client: IntegrationInstance):
+    route = client.execute("ip route | grep {}".format(DESTINATION_IP))
+    assert route.startswith(EXPECTED_ROUTE)

tests/unittests/test_net.py

@@ -4820,6 +4820,9 @@ def test_routes_rendered(self):
             {'type': 'route', 'id': 6,
              'metric': 1, 'destination': '10.0.200.0/16',
              'gateway': '172.23.31.1'},
+            {'type': 'route', 'id': 7,
+             'metric': 1, 'destination': '10.0.0.100/32',
+             'gateway': '172.23.31.1'},
         ]
 
         files = self._render_and_read(
@@ -4843,6 +4846,10 @@ def test_routes_rendered(self):
              '172.23.31.1 metric 1 || true'),
             ('pre-down route del -net 10.0.200.0/16 gw '
              '172.23.31.1 metric 1 || true'),
+            ('post-up route add -host 10.0.0.100/32 gw '
+             '172.23.31.1 metric 1 || true'),
+            ('pre-down route del -host 10.0.0.100/32 gw '
+             '172.23.31.1 metric 1 || true'),
         ]
         found = files['/etc/network/interfaces'].splitlines()
 

tools/.github-cla-signers

@@ -32,6 +32,7 @@ slyon
 smoser
 sshedi
 TheRealFalcon
+tnt-dev
 tomponline
 tsanghan
 WebSpider