fix(instances): the VM page reads the user's rights from the VM's own record

It looked the user's ownership up by the VM's name on its compute; names
are not unique there (a VM renamed outside the panel and a migration can
leave two), which gave a server error or another VM's rights on the page.

instances/tests/test_vm_page_records.py

@@ -0,0 +1,44 @@
+"""The VM page reads the user's rights from the VM's own record."""
+
+from unittest.mock import PropertyMock, patch
+
+from django.contrib.auth import get_user_model
+from django.test import TestCase
+from django.urls import reverse
+
+from accounts.models import UserInstance
+from computes.models import Compute
+from instances.models import Instance
+
+
+class VmPageRecordsTestCase(TestCase):
+    def setUp(self):
+        self.owner = get_user_model().objects.create_user("rows-owner", password="x")
+        self.compute = Compute.objects.create(name="rows-c", hostname="192.0.2.70", login="root", password="", type=1)
+        self.vm = Instance.objects.create(compute=self.compute, name="web", uuid="aaaaaaaa-0000-0000-0000-000000000071")
+        UserInstance.objects.create(instance=self.vm, user=self.owner, is_change=False)
+        self.client.force_login(self.owner)
+
+    def page(self, wvm_error=None):
+        with patch("instances.models.wvmInstance", side_effect=wvm_error) as wvm, patch.object(
+            Compute, "status", new_callable=PropertyMock, return_value=True
+        ):
+            proxy = wvm.return_value
+            proxy.get_memory.return_value = proxy.get_cur_memory.return_value = 1024
+            proxy.get_max_memory.return_value = 4096
+            proxy.get_hostdevs.return_value = ([], [], [])
+            proxy.get_console_type.return_value = "vnc"
+            proxy.get_status.return_value = 5
+            for getter in ("get_networks", "get_ifaces", "get_storages", "get_disk_devices", "get_media_devices",
+                           "get_net_devices"):
+                getattr(proxy, getter).return_value = []
+            return self.client.get(reverse("instances:instance", args=[self.vm.id]))
+
+    def test_the_rights_come_from_the_vms_own_record(self):
+        # another VM of the same name on the compute, owned with more rights:
+        # its record was not refreshed after a rename outside the panel
+        other = Instance.objects.create(compute=self.compute, name="web", uuid="aaaaaaaa-0000-0000-0000-000000000072")
+        UserInstance.objects.create(instance=other, user=self.owner, is_change=True)
+        response = self.page()
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.context["userinstance"].instance, self.vm)

instances/views.py

@@ -288,11 +288,7 @@ def _instance_page(request, pk, instance, compute):
     console_listener_addresses = settings.QEMU_CONSOLE_LISTENER_ADDRESSES
     ipv4_addresses = [address for net in instance.networks for address in net["ipv4"] or []]
     try:
-        userinstance = UserInstance.objects.get(
-            instance__compute_id=compute.id,
-            instance__name=instance.name,
-            user__id=request.user.id,
-        )
+        userinstance = UserInstance.objects.get(instance=instance, user=request.user)
     except UserInstance.DoesNotExist:
         userinstance = None
     # The page offers only what the backend allows this user (get_instance