sysconfig: support subnet type of 'manual'.

The subnet type 'manual' was used as a way to declare a device
and set an MTU for it but not assign network addresses.

This updates the manual example config to handle that case and
provides expected rendered output for sysconfig, eni, and netplan.

2 files changed, 82 insertions, 3 deletions

diff --git a/cloudinit/net/sysconfig.py b/cloudinit/net/sysconfig.py
index 9184bce6..a550f97c 100644
--- a/cloudinit/net/sysconfig.py
+++ b/cloudinit/net/sysconfig.py
@@ -61,6 +61,9 @@ class ConfigMap(object):
     def __getitem__(self, key):
         return self._conf[key]
 
+    def __contains__(self, key):
+        return key in self._conf
+
     def drop(self, key):
         self._conf.pop(key, None)
 
@@ -298,14 +301,16 @@ class Renderer(renderer.Renderer):
                 if subnet_is_ipv6(subnet):
                     mtu_key = 'IPV6_MTU'
                     iface_cfg['IPV6INIT'] = True
-
                 if 'mtu' in subnet:
                     iface_cfg[mtu_key] = subnet['mtu']
+            elif subnet_type == 'manual':
+                # If the subnet has an MTU setting, then ONBOOT=True
+                # to apply the setting
+                iface_cfg['ONBOOT'] = mtu_key in iface_cfg
             else:
                 raise ValueError("Unknown subnet type '%s' found"
                                  " for interface '%s'" % (subnet_type,
                                                           iface_cfg.name))
-
             if subnet.get('control') == 'manual':
                 iface_cfg['ONBOOT'] = False
 
diff --git a/tests/unittests/test_net.py b/tests/unittests/test_net.py
index caf31342..e49abcc4 100644
--- a/tests/unittests/test_net.py
+++ b/tests/unittests/test_net.py
@@ -1241,7 +1241,20 @@ pre-down route del -net 10.0.0.0 netmask 255.0.0.0 gw 11.0.0.1 metric 3 || true
                 subnets:
                   - type: static
                     address: 192.168.1.2/24
-                    control: manual"""),
+                    control: manual
+              - type: physical
+                name: eth1
+                mtu: 1480
+                mac_address: "52:54:00:12:34:aa"
+                subnets:
+                  - type: manual
+              - type: physical
+                name: eth2
+                mac_address: "52:54:00:12:34:ff"
+                subnets:
+                  - type: manual
+                    control: manual
+                  """),
         'expected_eni': textwrap.dedent("""\
             auto lo
             iface lo inet loopback
@@ -1249,6 +1262,34 @@ pre-down route del -net 10.0.0.0 netmask 255.0.0.0 gw 11.0.0.1 metric 3 || true
             # control-manual eth0
             iface eth0 inet static
                 address 192.168.1.2/24
+
+            auto eth1
+            iface eth1 inet manual
+                mtu 1480
+
+            # control-manual eth2
+            iface eth2 inet manual
+            """),
+        'expected_netplan': textwrap.dedent("""\
+
+            network:
+                version: 2
+                ethernets:
+                    eth0:
+                        addresses:
+                        - 192.168.1.2/24
+                        match:
+                            macaddress: '52:54:00:12:34:00'
+                        set-name: eth0
+                    eth1:
+                        match:
+                            macaddress: 52:54:00:12:34:aa
+                        mtu: 1480
+                        set-name: eth1
+                    eth2:
+                        match:
+                            macaddress: 52:54:00:12:34:ff
+                        set-name: eth2
             """),
         'expected_sysconfig': {
             'ifcfg-eth0': textwrap.dedent("""\
@@ -1262,6 +1303,25 @@ pre-down route del -net 10.0.0.0 netmask 255.0.0.0 gw 11.0.0.1 metric 3 || true
                 TYPE=Ethernet
                 USERCTL=no
                 """),
+            'ifcfg-eth1': textwrap.dedent("""\
+                BOOTPROTO=none
+                DEVICE=eth1
+                HWADDR=52:54:00:12:34:aa
+                MTU=1480
+                NM_CONTROLLED=no
+                ONBOOT=yes
+                TYPE=Ethernet
+                USERCTL=no
+                """),
+            'ifcfg-eth2': textwrap.dedent("""\
+                BOOTPROTO=none
+                DEVICE=eth2
+                HWADDR=52:54:00:12:34:ff
+                NM_CONTROLLED=no
+                ONBOOT=no
+                TYPE=Ethernet
+                USERCTL=no
+                """),
         },
     },
 }
@@ -2124,6 +2184,13 @@ class TestNetplanRoundTrip(CiTestCase):
             entry['expected_netplan'].splitlines(),
             files['/etc/netplan/50-cloud-init.yaml'].splitlines())
 
+    def testsimple_render_manual(self):
+        entry = NETWORK_CONFIGS['manual']
+        files = self._render_and_read(network_config=yaml.load(entry['yaml']))
+        self.assertEqual(
+            entry['expected_netplan'].splitlines(),
+            files['/etc/netplan/50-cloud-init.yaml'].splitlines())
+
 
 class TestEniRoundTrip(CiTestCase):
     def _render_and_read(self, network_config=None, state=None, eni_path=None,
@@ -2183,6 +2250,13 @@ class TestEniRoundTrip(CiTestCase):
             files['/etc/network/interfaces'].splitlines())
 
     def testsimple_render_manual(self):
+        """Test rendering of 'manual' for 'type' and 'control'.
+
+        'type: manual' in a subnet is odd, but it is the way that was used
+        to declare that a network device should get a mtu set on it even
+        if there were no addresses to configure.  Also strange is the fact
+        that in order to apply that MTU the ifupdown device must be set
+        to 'auto', or the MTU would not be set."""
         entry = NETWORK_CONFIGS['manual']
         files = self._render_and_read(network_config=yaml.load(entry['yaml']))
         self.assertEqual(