freebsd/net_v1 format: read MTU from root (#930)

We read the MTU from the subnet entries. With the v1 format, the MTU can
be set at the root level of the interface entry in the `config` section.

Limitation, we won't set the MTU if the interface use DHCP. This
would require a bit of refactoring.

Also simplify/clarify how we pass the target variable in `cloudinit.net.bsd`.

See: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=256309
Reported-by: Andrey Fesenko

2 files changed, 69 insertions, 10 deletions

diff --git a/cloudinit/net/bsd.py b/cloudinit/net/bsd.py
index aab968a8..916cea32 100644
--- a/cloudinit/net/bsd.py
+++ b/cloudinit/net/bsd.py
@@ -33,7 +33,7 @@ class BSDRenderer(renderer.Renderer):
         self.interface_configurations = {}
         self._postcmds = config.get('postcmds', True)
 
-    def _ifconfig_entries(self, settings, target=None):
+    def _ifconfig_entries(self, settings):
         ifname_by_mac = net.get_interfaces_by_mac()
         for interface in settings.iter_interfaces():
             device_name = interface.get("name")
@@ -76,10 +76,10 @@ class BSDRenderer(renderer.Renderer):
                     self.interface_configurations[device_name] = {
                         'address': subnet.get('address'),
                         'netmask': subnet.get('netmask'),
-                        'mtu': subnet.get('mtu'),
+                        'mtu': subnet.get('mtu') or interface.get('mtu'),
                     }
 
-    def _route_entries(self, settings, target=None):
+    def _route_entries(self, settings):
         routes = list(settings.iter_routes())
         for interface in settings.iter_interfaces():
             subnets = interface.get("subnets", [])
@@ -102,7 +102,7 @@ class BSDRenderer(renderer.Renderer):
             gateway = route.get('gateway')
             self.set_route(network, netmask, gateway)
 
-    def _resolve_conf(self, settings, target=None):
+    def _resolve_conf(self, settings):
         nameservers = settings.dns_nameservers
         searchdomains = settings.dns_searchdomains
         for interface in settings.iter_interfaces():
@@ -115,11 +115,11 @@ class BSDRenderer(renderer.Renderer):
         # fails.
         try:
             resolvconf = ResolvConf(util.load_file(subp.target_path(
-                target, self.resolv_conf_fn)))
+                self.target, self.resolv_conf_fn)))
             resolvconf.parse()
         except IOError:
             util.logexc(LOG, "Failed to parse %s, use new empty file",
-                        subp.target_path(target, self.resolv_conf_fn))
+                        subp.target_path(self.target, self.resolv_conf_fn))
             resolvconf = ResolvConf('')
             resolvconf.parse()
 
@@ -137,10 +137,12 @@ class BSDRenderer(renderer.Renderer):
             except ValueError:
                 util.logexc(LOG, "Failed to add search domain %s", domain)
         util.write_file(
-            subp.target_path(target, self.resolv_conf_fn),
+            subp.target_path(self.target, self.resolv_conf_fn),
             str(resolvconf), 0o644)
 
     def render_network_state(self, network_state, templates=None, target=None):
+        if target:
+            self.target = target
         self._ifconfig_entries(settings=network_state)
         self._route_entries(settings=network_state)
         self._resolve_conf(settings=network_state)
diff --git a/tests/unittests/test_net_freebsd.py b/tests/unittests/test_net_freebsd.py
index 414b4830..466d472b 100644
--- a/tests/unittests/test_net_freebsd.py
+++ b/tests/unittests/test_net_freebsd.py
@@ -1,8 +1,24 @@
-from cloudinit import net
+import os
+import yaml
+
+import cloudinit.net
+import cloudinit.net.network_state
+from cloudinit.tests.helpers import (CiTestCase, mock, readResource, dir2dict)
 
-from cloudinit.tests.helpers import (CiTestCase, mock, readResource)
 
 SAMPLE_FREEBSD_IFCONFIG_OUT = readResource("netinfo/freebsd-ifconfig-output")
+V1 = """
+config:
+-   id: eno1
+    mac_address: 08:94:ef:51:ae:e0
+    mtu: 1470
+    name: eno1
+    subnets:
+    -   address: 172.20.80.129/25
+        type: static
+    type: physical
+version: 1
+"""
 
 
 class TestInterfacesByMac(CiTestCase):
@@ -12,8 +28,49 @@ class TestInterfacesByMac(CiTestCase):
     def test_get_interfaces_by_mac(self, mock_is_FreeBSD, mock_subp):
         mock_is_FreeBSD.return_value = True
         mock_subp.return_value = (SAMPLE_FREEBSD_IFCONFIG_OUT, 0)
-        a = net.get_interfaces_by_mac()
+        a = cloudinit.net.get_interfaces_by_mac()
         assert a == {'52:54:00:50:b7:0d': 'vtnet0',
                      '80:00:73:63:5c:48': 're0.33',
                      '02:14:39:0e:25:00': 'bridge0',
                      '02:ff:60:8c:f3:72': 'vnet0:11'}
+
+
+class TestFreeBSDRoundTrip(CiTestCase):
+
+    def _render_and_read(self, network_config=None, state=None,
+                         netplan_path=None, target=None):
+        if target is None:
+            target = self.tmp_dir()
+            os.mkdir("%s/etc" % target)
+            with open("%s/etc/rc.conf" % target, 'a') as fd:
+                fd.write("# dummy rc.conf\n")
+            with open("%s/etc/resolv.conf" % target, 'a') as fd:
+                fd.write("# dummy resolv.conf\n")
+
+        if network_config:
+            ns = cloudinit.net.network_state.parse_net_config_data(
+                network_config)
+        elif state:
+            ns = state
+        else:
+            raise ValueError("Expected data or state, got neither")
+
+        renderer = cloudinit.net.freebsd.Renderer()
+        renderer.render_network_state(ns, target=target)
+        return dir2dict(target)
+
+    @mock.patch('cloudinit.subp.subp')
+    def test_render_output_has_yaml(self, mock_subp):
+
+        entry = {
+            'yaml': V1,
+        }
+        network_config = yaml.load(entry['yaml'])
+        ns = cloudinit.net.network_state.parse_net_config_data(network_config)
+        files = self._render_and_read(state=ns)
+        assert files == {
+            '/etc/resolv.conf': '# dummy resolv.conf\n',
+            '/etc/rc.conf': (
+                "# dummy rc.conf\n"
+                "ifconfig_eno1="
+                "'172.20.80.129 netmask 255.255.255.128 mtu 1470'\n")}