Merge lp:~julian-edwards/maas/backport-network-mac-linkage into lp:maas/1.6

[Julian Edwards]

Backport changes from trunk that fix bug 1341619, which creates Networks from cluster interfaces and auto-links MAC addresses from nodes to them.

[Julian Edwards (julian-edwards)]

Selfing straight backport

review: Approve

[MAAS Lander (maas-lander)]

The attempt to merge lp:~julian-edwards/maas/backport-network-mac-linkage into lp:maas/1.6 failed. Below is the output from the failed tests.

Ign http://security.ubuntu.com trusty-security InRelease
Hit http://security.ubuntu.com trusty-security Release.gpg
Ign http://nova.clouds.archive.ubuntu.com trusty InRelease
Hit http://security.ubuntu.com trusty-security Release
Ign http://nova.clouds.archive.ubuntu.com trusty-updates InRelease
Hit http://nova.clouds.archive.ubuntu.com trusty Release.gpg
Hit http://nova.clouds.archive.ubuntu.com trusty-updates Release.gpg
Hit http://nova.clouds.archive.ubuntu.com trusty Release
Hit http://nova.clouds.archive.ubuntu.com trusty-updates Release
Hit http://security.ubuntu.com trusty-security/main Sources
Hit http://security.ubuntu.com trusty-security/universe Sources
Hit http://security.ubuntu.com trusty-security/main amd64 Packages
Hit http://security.ubuntu.com trusty-security/universe amd64 Packages
Hit http://security.ubuntu.com trusty-security/main Translation-en
Hit http://security.ubuntu.com trusty-security/universe Translation-en
Hit http://nova.clouds.archive.ubuntu.com trusty/main Sources
Hit http://nova.clouds.archive.ubuntu.com trusty/universe Sources
Hit http://nova.clouds.archive.ubuntu.com trusty/main amd64 Packages
Hit http://nova.clouds.archive.ubuntu.com trusty/universe amd64 Packages
Hit http://nova.clouds.archive.ubuntu.com trusty/main Translation-en
Hit http://nova.clouds.archive.ubuntu.com trusty/universe Translation-en
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/main Sources
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/universe Sources
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/main amd64 Packages
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/universe amd64 Packages
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/main Translation-en
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/universe Translation-en
Ign http://nova.clouds.archive.ubuntu.com trusty/main Translation-en_US
Ign http://nova.clouds.archive.ubuntu.com trusty/universe Translation-en_US
Reading package lists...
sudo DEBIAN_FRONTEND=noninteractive apt-get -y \
     --no-install-recommends install apache2 bind9 bind9utils build-essential bzr-builddeb curl daemontools debhelper dh-apport distro-info dnsutils firefox freeipmi-tools ipython isc-dhcp-common libjs-raphael libjs-yui3-full libjs-yui3-min libpq-dev make postgresql python-amqplib python-bzrlib python-celery python-convoy python-crochet python-cssselect python-curtin python-dev python-distro-info python-django python-django-piston python-django-south python-djorm-ext-pgarray python-docutils python-formencode python-hivex python-httplib2 python-jinja2 python-jsonschema python-lockfile python-lxml python-netaddr python-netifaces python-oauth python-oops python-oops-amqp python-oops-datedir-repo python-oops-twisted python-oops-wsgi python-openssl python-paramiko python-pexpect python-pip python-pocket-lint python-psycopg2 python-pyinotify python-seamicroclient python-simplestreams python-sphinx python-tempita python-twisted python-txamqp python-txlongpoll python-txtftp python-virtualenv python-yaml rab...

[MAAS Lander (maas-lander)]

The attempt to merge lp:~julian-edwards/maas/backport-network-mac-linkage into lp:maas/1.6 failed. Below is the output from the failed tests.

Ign http://security.ubuntu.com trusty-security InRelease
Hit http://security.ubuntu.com trusty-security Release.gpg
Hit http://security.ubuntu.com trusty-security Release
Ign http://nova.clouds.archive.ubuntu.com trusty InRelease
Ign http://nova.clouds.archive.ubuntu.com trusty-updates InRelease
Hit http://nova.clouds.archive.ubuntu.com trusty Release.gpg
Hit http://nova.clouds.archive.ubuntu.com trusty-updates Release.gpg
Hit http://nova.clouds.archive.ubuntu.com trusty Release
Hit http://nova.clouds.archive.ubuntu.com trusty-updates Release
Hit http://security.ubuntu.com trusty-security/main Sources
Hit http://security.ubuntu.com trusty-security/universe Sources
Hit http://security.ubuntu.com trusty-security/main amd64 Packages
Hit http://security.ubuntu.com trusty-security/universe amd64 Packages
Hit http://security.ubuntu.com trusty-security/main Translation-en
Hit http://security.ubuntu.com trusty-security/universe Translation-en
Hit http://nova.clouds.archive.ubuntu.com trusty/main Sources
Hit http://nova.clouds.archive.ubuntu.com trusty/universe Sources
Hit http://nova.clouds.archive.ubuntu.com trusty/main amd64 Packages
Hit http://nova.clouds.archive.ubuntu.com trusty/universe amd64 Packages
Hit http://nova.clouds.archive.ubuntu.com trusty/main Translation-en
Hit http://nova.clouds.archive.ubuntu.com trusty/universe Translation-en
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/main Sources
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/universe Sources
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/main amd64 Packages
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/universe amd64 Packages
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/main Translation-en
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/universe Translation-en
Ign http://nova.clouds.archive.ubuntu.com trusty/main Translation-en_US
Ign http://nova.clouds.archive.ubuntu.com trusty/universe Translation-en_US
Reading package lists...
sudo DEBIAN_FRONTEND=noninteractive apt-get -y \
     --no-install-recommends install apache2 bind9 bind9utils build-essential bzr-builddeb curl daemontools debhelper dh-apport distro-info dnsutils firefox freeipmi-tools ipython isc-dhcp-common libjs-raphael libjs-yui3-full libjs-yui3-min libpq-dev make postgresql python-amqplib python-bzrlib python-celery python-convoy python-crochet python-cssselect python-curtin python-dev python-distro-info python-django python-django-piston python-django-south python-djorm-ext-pgarray python-docutils python-formencode python-hivex python-httplib2 python-jinja2 python-jsonschema python-lockfile python-lxml python-netaddr python-netifaces python-oauth python-oops python-oops-amqp python-oops-datedir-repo python-oops-twisted python-oops-wsgi python-openssl python-paramiko python-pexpect python-pip python-pocket-lint python-psycopg2 python-pyinotify python-seamicroclient python-simplestreams python-sphinx python-tempita python-twisted python-txamqp python-txlongpoll python-txtftp python-virtualenv python-yaml rab...

[MAAS Lander (maas-lander)]

The attempt to merge lp:~julian-edwards/maas/backport-network-mac-linkage into lp:maas/1.6 failed. Below is the output from the failed tests.

Ign http://security.ubuntu.com trusty-security InRelease
Ign http://nova.clouds.archive.ubuntu.com trusty InRelease
Hit http://security.ubuntu.com trusty-security Release.gpg
Ign http://nova.clouds.archive.ubuntu.com trusty-updates InRelease
Hit http://security.ubuntu.com trusty-security Release
Hit http://nova.clouds.archive.ubuntu.com trusty Release.gpg
Hit http://nova.clouds.archive.ubuntu.com trusty-updates Release.gpg
Hit http://nova.clouds.archive.ubuntu.com trusty Release
Hit http://nova.clouds.archive.ubuntu.com trusty-updates Release
Hit http://security.ubuntu.com trusty-security/main Sources
Hit http://security.ubuntu.com trusty-security/universe Sources
Hit http://security.ubuntu.com trusty-security/main amd64 Packages
Hit http://security.ubuntu.com trusty-security/universe amd64 Packages
Hit http://security.ubuntu.com trusty-security/main Translation-en
Hit http://security.ubuntu.com trusty-security/universe Translation-en
Hit http://nova.clouds.archive.ubuntu.com trusty/main Sources
Hit http://nova.clouds.archive.ubuntu.com trusty/universe Sources
Hit http://nova.clouds.archive.ubuntu.com trusty/main amd64 Packages
Hit http://nova.clouds.archive.ubuntu.com trusty/universe amd64 Packages
Hit http://nova.clouds.archive.ubuntu.com trusty/main Translation-en
Hit http://nova.clouds.archive.ubuntu.com trusty/universe Translation-en
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/main Sources
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/universe Sources
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/main amd64 Packages
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/universe amd64 Packages
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/main Translation-en
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/universe Translation-en
Ign http://nova.clouds.archive.ubuntu.com trusty/main Translation-en_US
Ign http://nova.clouds.archive.ubuntu.com trusty/universe Translation-en_US
Reading package lists...
sudo DEBIAN_FRONTEND=noninteractive apt-get -y \
     --no-install-recommends install apache2 bind9 bind9utils build-essential bzr-builddeb curl daemontools debhelper dh-apport distro-info dnsutils firefox freeipmi-tools ipython isc-dhcp-common libjs-raphael libjs-yui3-full libjs-yui3-min libpq-dev make postgresql python-amqplib python-bzrlib python-celery python-convoy python-crochet python-cssselect python-curtin python-dev python-distro-info python-django python-django-piston python-django-south python-djorm-ext-pgarray python-docutils python-formencode python-hivex python-httplib2 python-jinja2 python-jsonschema python-lockfile python-lxml python-netaddr python-netifaces python-oauth python-oops python-oops-amqp python-oops-datedir-repo python-oops-twisted python-oops-wsgi python-openssl python-paramiko python-pexpect python-pip python-pocket-lint python-psycopg2 python-pyinotify python-seamicroclient python-simplestreams python-sphinx python-tempita python-twisted python-txamqp python-txlongpoll python-txtftp python-virtualenv python-yaml rab...

[Julian Edwards (julian-edwards)]

FML

=== modified file 'src/maasserver/api.py'
--- src/maasserver/api.py	2014-08-08 20:09:49 +0000
+++ src/maasserver/api.py	2014-08-20 02:35:32 +0000
@@ -1589,17 +1589,33 @@
     for interface in interfaces:
         ip_range = netaddr.IPRange(
             interface.ip_range_low, interface.ip_range_high)
-        interface_ranges[interface] = ip_range
+        if interface.static_ip_range_low and interface.static_ip_range_high:
+            static_range = netaddr.IPRange(
+                interface.static_ip_range_low, interface.static_ip_range_high)
+        else:
+            static_range = []
+        interface_ranges[interface] = (ip_range, static_range)
     for ip, mac in leases.items():
         try:
             mac_address = MACAddress.objects.get(mac_address=mac)
         except MACAddress.DoesNotExist:
             # Silently ignore MAC addresses that we don't know about.
             continue
-        for interface, ip_range in interface_ranges.items():
-            if netaddr.IPAddress(ip) in ip_range:
+        for interface, (ip_range, static_range) in interface_ranges.items():
+            ipaddress = netaddr.IPAddress(ip)
+            if ipaddress in ip_range or ipaddress in static_range:
                 mac_address.cluster_interface = interface
                 mac_address.save()
+
+                # Locate the Network to which this MAC belongs.
+                ipnetwork = interface.network
+                if ipnetwork is not None:
+                    try:
+                        network = Network.objects.get(ip=ipnetwork.ip.format())
+                        network.macaddress_set.add(mac_address)
+                    except Network.DoesNotExist:
+                        pass
+
                 # Cheap optimisation. No other interfaces will match, so
                 # break out of the loop.
                 break

=== modified file 'src/maasserver/forms.py'
--- src/maasserver/forms.py	2014-07-09 08:45:22 +0000
+++ src/maasserver/forms.py	2014-08-20 02:35:32 +0000
@@ -18,6 +18,7 @@
     "BootSourceForm",
     "BootSourceSelectionForm",
     "BulkNodeActionForm",
+    "create_Network_from_NodeGroupInterface",
     "CommissioningForm",
     "CommissioningScriptForm",
     "DownloadProgressForm",
@@ -110,6 +111,7 @@
     Tag,
     Zone,
     )
+from maasserver.models.network import get_name_and_vlan_from_cluster_interface
 from maasserver.models.nodegroup import NODEGROUP_CLUSTER_NAME_TEMPLATE
 from maasserver.node_action import (
     ACTION_CLASSES,
@@ -1127,6 +1129,33 @@
     return True
 
 
+def create_Network_from_NodeGroupInterface(interface):
+    """Given a `NodeGroupInterface`, create its Network counterpart."""
+    # This method cannot use non-orm model properties because it needs
+    # to be used in a data migration, where they won't work.
+    if not interface.subnet_mask:
+        # Can be None or empty string, do nothing if so.
+        return
+
+    name, vlan_tag = get_name_and_vlan_from_cluster_interface(interface)
+    ipnetwork = make_network(interface.ip, interface.subnet_mask)
+    network = Network(
+        name=name,
+        ip=unicode(ipnetwork.network),
+        netmask=unicode(ipnetwork.netmask),
+        vlan_tag=vlan_tag,
+        description=(
+            "Auto created when creating interface %s on cluster "
+            "%s" % (interface.interface, interface.nodegroup.name)),
+        )
+    try:
+        network.save()
+    except ValidationError:
+        # It probably already exists, keep calm and carry on.
+        return
+    return network
+
+
 class NodeGroupInterfaceForm(ModelForm):
 
     management = forms.TypedChoiceField(
@@ -1154,6 +1183,15 @@
             'static_ip_range_high',
             )
 
+    def save(self, *args, **kwargs):
+        """Override `ModelForm`.save() so that the network data is copied
+        to a `Network` instance."""
+        interface = super(NodeGroupInterfaceForm, self).save(*args, **kwargs)
+        if interface.network is None:
+            return interface
+        create_Network_from_NodeGroupInterface(interface)
+        return interface
+
     def clean(self):
         cleaned_data = super(NodeGroupInterfaceForm, self).clean()
         static_ip_range_low = cleaned_data.get('static_ip_range_low')

=== modified file 'src/maasserver/models/network.py'
--- src/maasserver/models/network.py	2014-07-08 07:33:43 +0000
+++ src/maasserver/models/network.py	2014-08-20 02:35:32 +0000
@@ -186,6 +186,22 @@
     return specifier_class(spec)
 
 
+def get_name_and_vlan_from_cluster_interface(cluster_interface):
+    """Given a `NodeGroupInterface`, return a name suitable for a `Network`.
+
+    :return: a tuple of the new name and vlan tag. vlan tag may be None
+    """
+    name = cluster_interface.interface
+    nodegroup_name = cluster_interface.nodegroup.name
+    vlan_tag = None
+    if '.' in name:
+        _, vlan_tag = name.split('.', 1)
+        name = name.replace('.', '-')
+    name = name.replace(':', '-')
+    network_name = "-".join((nodegroup_name, name))
+    return network_name, vlan_tag
+
+
 class NetworkManager(Manager):
     """Manager for :class:`Network` model class.
 

=== modified file 'src/maasserver/models/tests/test_network.py'
--- src/maasserver/models/tests/test_network.py	2014-06-30 14:46:10 +0000
+++ src/maasserver/models/tests/test_network.py	2014-08-20 02:35:32 +0000
@@ -22,12 +22,14 @@
 from maasserver.models.network import (
     get_specifier_type,
     IPSpecifier,
+    get_name_and_vlan_from_cluster_interface,
     NameSpecifier,
     parse_network_spec,
     VLANSpecifier,
     )
 from maasserver.testing.factory import factory
 from maasserver.testing.testcase import MAASServerTestCase
+from mock import sentinel
 from netaddr import (
     IPAddress,
     IPNetwork,
@@ -129,6 +131,43 @@
         self.assertRaises(ValidationError, parse_network_spec, '10.4.4.4')
 
 
+class TestGetNameAndVlanFromClusterInterface(MAASServerTestCase):
+    """Tests for `get_name_and_vlan_from_cluster_interface`."""
+
+    def make_interface_name(self, basename):
+        interface = sentinel.interface
+        interface.nodegroup = sentinel.nodegroup
+        interface.nodegroup.name = factory.make_name('name')
+        interface.interface = basename
+        return interface
+
+    def test_returns_simple_name_unaltered(self):
+        interface = self.make_interface_name(factory.make_name('iface'))
+        name, vlan_tag = get_name_and_vlan_from_cluster_interface(interface)
+        expected_name = '%s-%s' % (
+            interface.nodegroup.name, interface.interface)
+        self.assertEqual((expected_name, None), (name, vlan_tag))
+
+    def test_substitutes_colon(self):
+        interface = self.make_interface_name('eth0:0')
+        name, vlan_tag = get_name_and_vlan_from_cluster_interface(interface)
+        expected_name = '%s-eth0-0' % interface.nodegroup.name
+        self.assertEqual((expected_name, None), (name, vlan_tag))
+
+    def test_returns_with_vlan_tag(self):
+        interface = self.make_interface_name('eth0.5')
+        name, vlan_tag = get_name_and_vlan_from_cluster_interface(interface)
+        expected_name = '%s-eth0-5' % interface.nodegroup.name
+        self.assertEqual((expected_name, '5'), (name, vlan_tag))
+
+    def test_returns_name_with_crazy_colon_and_vlan(self):
+        # For truly twisted network admins.
+        interface = self.make_interface_name('eth0:2.3')
+        name, vlan_tag = get_name_and_vlan_from_cluster_interface(interface)
+        expected_name = '%s-eth0-2-3' % interface.nodegroup.name
+        self.assertEqual((expected_name, '3'), (name, vlan_tag))
+
+
 class TestNetworkManager(MAASServerTestCase):
 
     def test_get_from_spec_validates_first(self):

=== modified file 'src/maasserver/tests/test_api_nodegroup.py'
--- src/maasserver/tests/test_api_nodegroup.py	2014-07-03 09:19:18 +0000
+++ src/maasserver/tests/test_api_nodegroup.py	2014-08-20 02:35:32 +0000
@@ -32,6 +32,7 @@
     NODEGROUP_STATUS_CHOICES,
     NODEGROUPINTERFACE_MANAGEMENT,
     )
+from maasserver.forms import create_Network_from_NodeGroupInterface
 from maasserver.models import (
     Config,
     DHCPLease,
@@ -77,12 +78,16 @@
     )
 
 
-def get_random_ip_from_interface_range(interface):
+def get_random_ip_from_interface_range(interface, use_static_range=None):
     """Return a random IP from the pool available to an interface.
 
     :return: An IP address as a string."""
-    ip_range = netaddr.IPRange(
-        interface.ip_range_low, interface.ip_range_high)
+    if use_static_range:
+        ip_range = netaddr.IPRange(
+            interface.static_ip_range_low, interface.static_ip_range_high)
+    else:
+        ip_range = netaddr.IPRange(
+            interface.ip_range_low, interface.ip_range_high)
     chosen_ip = random.choice(ip_range)
     return unicode(chosen_ip)
 
@@ -830,7 +835,7 @@
 class TestUpdateMacClusterInterfaces(MAASServerTestCase):
     """Tests for `update_mac_cluster_interfaces`()."""
 
-    def test_updates_mac_cluster_interfaces(self):
+    def make_cluster_with_macs_and_leases(self, use_static_range=False):
         cluster = factory.make_node_group()
         mac_addresses = {
             factory.make_mac_address(): factory.make_node_group_interface(
@@ -838,17 +843,49 @@
             for i in range(4)
             }
         leases = {
-            get_random_ip_from_interface_range(interface): (
+            get_random_ip_from_interface_range(interface, use_static_range): (
                 mac_address.mac_address)
-            for mac_address, interface in mac_addresses.items()
+            for mac_address, interface in mac_addresses.viewitems()
         }
-        update_mac_cluster_interfaces(leases, cluster)
-        results = {
-            mac_address: mac_address.cluster_interface
-            for mac_address in MACAddress.objects.filter(
-                mac_address__in=leases.values())
-            }
-        self.assertEqual(mac_addresses, results)
+        return cluster, mac_addresses, leases
+
+    def test_updates_mac_cluster_interfaces(self):
+        cluster, mac_addresses, leases = (
+            self.make_cluster_with_macs_and_leases())
+        update_mac_cluster_interfaces(leases, cluster)
+        results = {
+            mac_address: mac_address.cluster_interface
+            for mac_address in MACAddress.objects.filter(
+                mac_address__in=leases.values())
+            }
+        self.assertEqual(mac_addresses, results)
+
+    def test_considers_static_range_when_updating_interfaces(self):
+        cluster, mac_addresses, leases = (
+            self.make_cluster_with_macs_and_leases(use_static_range=True))
+        update_mac_cluster_interfaces(leases, cluster)
+        results = {
+            mac_address: mac_address.cluster_interface
+            for mac_address in MACAddress.objects.filter(
+                mac_address__in=leases.values())
+            }
+        self.assertEqual(mac_addresses, results)
+
+    def test_updates_network_relations(self):
+        # update_mac_cluster_interfaces should also associate the mac
+        # with the network on which it resides.
+        cluster, mac_addresses, leases = (
+            self.make_cluster_with_macs_and_leases())
+        expected_relations = []
+        for mac, interface in mac_addresses.viewitems():
+            net = create_Network_from_NodeGroupInterface(interface)
+            expected_relations.append((net, mac))
+        update_mac_cluster_interfaces(leases, cluster)
+        # Doing a single giant comparison here would be unintuitive and
+        # fugly, so I'm iterating.
+        for net, mac in expected_relations:
+            [observed_macddress] = net.macaddress_set.all()
+            self.assertThat(mac, Equals(observed_macddress))
 
     def test_ignores_mac_not_attached_to_cluster(self):
         cluster = factory.make_node_group()

=== modified file 'src/maasserver/tests/test_forms.py'
--- src/maasserver/tests/test_forms.py	2014-07-09 11:18:41 +0000
+++ src/maasserver/tests/test_forms.py	2014-08-20 02:35:32 +0000
@@ -16,6 +16,7 @@
 
 from cStringIO import StringIO
 import json
+import random
 
 from django import forms
 from django.conf import settings
@@ -92,6 +93,7 @@
     Zone,
     )
 from maasserver.models.config import DEFAULT_CONFIG
+from maasserver.models.network import get_name_and_vlan_from_cluster_interface
 from maasserver.models.staticipaddress import StaticIPAddress
 from maasserver.node_action import (
     Commission,
@@ -1054,10 +1056,24 @@
     ]
 
 
+def make_ngi_instance(nodegroup=None):
+    """Create a `NodeGroupInterface` with nothing set but `nodegroup`.
+
+    This is used by tests to instantiate the cluster interface form for
+    a given cluster.  We create an initial cluster interface object just
+    to tell it which cluster that is.
+    """
+    if nodegroup is None:
+        nodegroup = factory.make_node_group()
+    return NodeGroupInterface(nodegroup=nodegroup)
+
+
 class TestNodeGroupInterfaceForm(MAASServerTestCase):
 
     def test_NodeGroupInterfaceForm_validates_parameters(self):
-        form = NodeGroupInterfaceForm(data={'ip': factory.getRandomString()})
+        form = NodeGroupInterfaceForm(
+            data={'ip': factory.getRandomString()},
+            instance=make_ngi_instance())
         self.assertFalse(form.is_valid())
         self.assertEquals(
             {'ip': ['Enter a valid IPv4 or IPv6 address.']}, form._errors)
@@ -1069,8 +1085,7 @@
             del int_settings[field_name]
         nodegroup = factory.make_node_group()
         form = NodeGroupInterfaceForm(
-            data=int_settings,
-            instance=NodeGroupInterface(nodegroup=nodegroup))
+            data=int_settings, instance=make_ngi_instance(nodegroup))
         interface = form.save()
         field_values = [
             getattr(interface, field_name) for field_name in nullable_fields]
@@ -1097,6 +1112,75 @@
             form._errors['static_ip_range_high'])
 
 
+class TestNodeGroupInterfaceFormNetworkCreation(MAASServerTestCase):
+    """Tests for when NodeGroupInterfaceForm creates a Network."""
+
+    def test_creates_network_name(self):
+        int_settings = factory.get_interface_fields()
+        int_settings['interface'] = 'eth0:1'
+        interface = make_ngi_instance()
+        form = NodeGroupInterfaceForm(data=int_settings, instance=interface)
+        form.save()
+        [network] = Network.objects.all()
+        expected, _ = get_name_and_vlan_from_cluster_interface(interface)
+        self.assertEqual(expected, network.name)
+
+    def test_sets_vlan_tag(self):
+        int_settings = factory.get_interface_fields()
+        vlan_tag = random.randint(1, 10)
+        int_settings['interface'] = 'eth0.%s' % vlan_tag
+        interface = make_ngi_instance()
+        form = NodeGroupInterfaceForm(data=int_settings, instance=interface)
+        form.save()
+        [network] = Network.objects.all()
+        self.assertEqual(vlan_tag, network.vlan_tag)
+
+    def test_vlan_tag_is_None_if_no_vlan(self):
+        int_settings = factory.get_interface_fields()
+        int_settings['interface'] = 'eth0:1'
+        interface = make_ngi_instance()
+        form = NodeGroupInterfaceForm(data=int_settings, instance=interface)
+        form.save()
+        [network] = Network.objects.all()
+        self.assertIs(None, network.vlan_tag)
+
+    def test_sets_network_values(self):
+        int_settings = factory.get_interface_fields()
+        interface = make_ngi_instance()
+        form = NodeGroupInterfaceForm(data=int_settings, instance=interface)
+        form.save()
+        [network] = Network.objects.all()
+        expected_net_address = unicode(interface.network.network)
+        expected_netmask = unicode(interface.network.netmask)
+        self.assertThat(
+            network, MatchesStructure.byEquality(
+                ip=expected_net_address,
+                netmask=expected_netmask))
+
+    def test_does_not_create_new_network_if_already_exists(self):
+        int_settings = factory.get_interface_fields()
+        interface = make_ngi_instance()
+        form = NodeGroupInterfaceForm(data=int_settings, instance=interface)
+        # The easiest way to pre-create the same network is just to save
+        # the form twice.
+        form.save()
+        [existing_network] = Network.objects.all()
+        form.save()
+        self.assertItemsEqual([existing_network], Network.objects.all())
+
+    def test_creates_many_unique_networks(self):
+        names = ('eth0', 'eth0:1', 'eth0.1', 'eth0:1.2')
+        for name in names:
+            int_settings = factory.get_interface_fields()
+            int_settings['interface'] = name
+            interface = make_ngi_instance()
+            form = NodeGroupInterfaceForm(
+                data=int_settings, instance=interface)
+            form.save()
+
+        self.assertEqual(len(names), len(Network.objects.all()))
+
+
 class TestValidateNewStaticIPRanges(MAASServerTestCase):
     """Tests for `validate_new_static_ip_ranges`()."""