network: use routes instead of gateway directives

subiquitycore/controllers/network.py

@@ -104,7 +104,6 @@ network:
          name: "en*"
        addresses:
          - 10.0.2.15/24
-       gateway4: 10.0.2.2
        nameservers:
          addresses:
            - 8.8.8.8
@@ -112,6 +111,9 @@ network:
          search:
            - foo
            - bar
+       routes:
+         - to: default
+           via: 10.0.2.2
     "all-eth":
        match:
          name: "eth*"
@@ -357,11 +359,13 @@ class BaseNetworkController(BaseController):
         dev = self.model.get_netdev_by_name(dev_name)
         dev.remove_ip_networks_for_version(ip_version)
         dev.config.setdefault('addresses', []).extend(static_config.addresses)
-        gwkey = 'gateway{v}'.format(v=ip_version)
         if static_config.gateway:
-            dev.config[gwkey] = static_config.gateway
+            dev.config['routes'] = [{
+                'to': 'default',
+                'via': static_config.gateway
+            }]
         else:
-            dev.config.pop(gwkey, None)
+            dev.remove_routes(ip_version)
         ns = dev.config.setdefault('nameservers', {})
         ns.setdefault('addresses', []).extend(static_config.nameservers)
         ns.setdefault('search', []).extend(static_config.searchdomains)

subiquitycore/models/network.py

@@ -391,7 +391,7 @@ class NetworkDev(object):
 
     def remove_ip_networks_for_version(self, version):
         self.config.pop('dhcp{v}'.format(v=version), None)
-        self.config.pop('gateway{v}'.format(v=version), None)
+        self.remove_routes(version)
         addrs = []
         for ip in self.config.get('addresses', []):
             if addr_version(ip) != version:
@@ -401,6 +401,14 @@ class NetworkDev(object):
         else:
             self.config.pop('addresses', None)
 
+    def remove_routes(self, version):
+        routes = [route for route in self.config.get('routes', [])
+                  if addr_version(route['via']) != version]
+        if routes:
+            self.config['routes'] = routes
+        else:
+            self.config.pop('routes', None)
+
 
 class NetworkModel(object):
     """ """

subiquitycore/models/tests/test_network.py

@@ -0,0 +1,41 @@
+# Copyright 2022 Canonical, Ltd.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from subiquitycore.models.network import NetworkDev
+from subiquitycore.tests import SubiTestCase
+
+
+class TestRouteManagement(SubiTestCase):
+    def setUp(self):
+        self.nd = NetworkDev(None, None, None)
+        self.ipv4s = [
+            {'to': 'default', 'via': '10.0.2.2'},
+            {'to': '1.2.3.0/24', 'via': '1.2.3.4'},
+        ]
+        self.ipv6s = [
+            {'to': 'default', 'via': '1111::2222'},
+            {'to': '3333::0/64', 'via': '3333::4444'},
+        ]
+        self.nd.config = {'routes': self.ipv4s + self.ipv6s}
+
+    def test_remove_v4(self):
+        self.nd.remove_routes(4)
+        expected = self.ipv6s
+        self.assertEqual(expected, self.nd.config['routes'])
+
+    def test_remove_v6(self):
+        self.nd.remove_routes(6)
+        expected = self.ipv4s
+        self.assertEqual(expected, self.nd.config['routes'])