vm: Add is_master attribute to interface, add new operation to set master interface

Interfaces can be now "master interface" of a vm. The vm's primary host is the master interface's host. The SetMasterInterface operation sets the specified interface as master. A vm can have only one interface, validated in the Interface save method.

circle/vm/migrations/0003_interface_is_master.py

+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.6 on 2018-10-29 13:39
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('vm', '0002_interface_model'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='interface',
+            name='is_master',
+            field=models.BooleanField(default=False),
+        ),
+    ]

circle/vm/models/instance.py

@@ -500,23 +500,34 @@ class Instance(AclBase, VirtualMachineDescModel, StatusModel, OperatedMixin,
 
     @property
     def primary_host(self):
-        interfaces = self.interface_set.select_related('host')
-        hosts = [i.host for i in interfaces if i.host]
-        if not hosts:
-            return None
-        hs = [h for h in hosts if h.ipv6]
-        if hs:
-            return hs[0]
-        hs = [h for h in hosts if not h.shared_ip]
-        if hs:
-            return hs[0]
-        return hosts[0]
+        """Primary host of the instance.
+
+        If the master interface is not specified, the primary host is random.
+        """
+        try:
+            master = self.interface_set.get(is_master=True)
+            if master.host:
+                return master.host
+        except Interface.DoesNotExist:
+            interfaces = self.interface_set.select_related('host')
+            hosts = [i.host for i in interfaces if i.host]
+            if not hosts:
+                    return None
+            hs = [h for h in hosts if h.ipv6]
+            if hs:
+                return hs[0]
+            hs = [h for h in hosts if not h.shared_ip]
+            if hs:
+                return hs[0]
+            return hosts[0]
 
     @property
     def ipv4(self):
         """Primary IPv4 address of the instance.
         """
         # return self.primary_host.ipv4 if self.primary_host else None
+        if self.primary_host:
+            return self.primary_host.ipv4
         for i in self.interface_set.all():
             if i.host:
                 return i.host.ipv4

circle/vm/models/network.py

@@ -69,6 +69,7 @@ class Interface(Model):
     host = ForeignKey(Host, verbose_name=_('host'),  blank=True, null=True)
     instance = ForeignKey('Instance', verbose_name=_('instance'),
                           related_name='interface_set')
+    is_master = BooleanField(default=False)
     model = CharField(max_length=10, choices=MODEL_TYPES, default='virtio')
 
     class Meta:
@@ -163,6 +164,23 @@ class Interface(Model):
         iface.save()
         return iface
 
+    def save(self, *args, **kwargs):
+        """Saves the Instance to the database
+
+        If the interface is master interface, sets
+        the another master interface to false.
+        """
+        if self.is_master:
+            try:
+                temp = Interface.objects.get(instance=self.instance,
+                                             is_master=True)
+                if self != temp:
+                    temp.is_master = False
+                    temp.save()
+            except Interface.DoesNotExist:
+                pass
+        super(Interface, self).save(*args, **kwargs)
+
     def deploy(self):
         queue_name = self.instance.get_remote_queue_name('net', 'fast')
         return net_tasks.create.apply_async(args=[self.get_vmnetwork_desc()],

circle/vm/operations.py

@@ -247,6 +247,29 @@ class AddInterfaceOperation(InstanceOperation):
 
 
 @register_operation
+class SetMasterInterfaceOperation(InstanceOperation):
+    id = 'set_master_interface'
+    name = _("set master interface")
+    description = _("Set the master interface of the VM.")
+    required_perms = ()
+    accept_states = ('STOPPED', 'PENDING')
+
+    def _operation(self, user, activity, interface):
+        if interface.host:
+            interface.is_master = True
+            interface.save()
+        else:
+            raise humanize_exception(ugettext_noop(
+                                     "Master interface must have host"),
+                                     Host.DoesNotExist())
+
+    def get_activity_name(self, kwargs):
+        return create_readable(ugettext_noop("set %(vlan)s interface"
+                                             " as master"),
+                               vlan=kwargs['interface'].vlan)
+
+
+@register_operation
 class CreateDiskOperation(InstanceOperation):
 
     id = 'create_disk'