Always use QubesVM objects, instead of AppVM/TemplateVM etc

Very few calls at client side really needs VM class name. So, even in
non-blind mode use just QubesVM class, to avoid strange cases depending
on blind mode being enabled or not. Then, have VM class name in 'klass'
property. If known at object creation time, cache it, otherwise query
qubesd at first access.

qubesadmin/app.py

@@ -86,12 +86,14 @@ class VMCollection(object):
         if not self.app.blind_mode and item not in self:
             raise KeyError(item)
         if item not in self._vm_objects:
-            if self.app.blind_mode:
-                cls = qubesadmin.vm.QubesVM
-            else:
-                cls = qubesadmin.utils.get_entry_point_one(VM_ENTRY_POINT,
-                    self._vm_list[item]['class'])
-            self._vm_objects[item] = cls(self.app, item)
+            cls = qubesadmin.vm.QubesVM
+            # provide class name to constructor, if already cached (which can be
+            # done by 'item not in self' check above, unless blind_mode is
+            # enabled
+            klass = None
+            if self._vm_list and item in self._vm_list:
+                klass = self._vm_list[item]['class']
+            self._vm_objects[item] = cls(self.app, item, klass=klass)
         return self._vm_objects[item]
 
     def __contains__(self, item):
@@ -312,7 +314,7 @@ class QubesBase(qubesadmin.base.PropertyHolder):
             src_vm = self.domains[src_vm]
 
         if new_cls is None:
-            new_cls = src_vm.__class__.__name__
+            new_cls = src_vm.klass
 
         template = getattr(src_vm, 'template', None)
         if template is not None:

qubesadmin/backup/restore.py

@@ -1456,7 +1456,7 @@ class BackupRestore(object):
                 except KeyError:
                     host_template = None
                 present_on_host = (host_template and
-                    isinstance(host_template, qubesadmin.vm.TemplateVM))
+                    host_template.klass == 'TemplateVM')
                 present_in_backup = (template_name in restore_info.keys() and
                     restore_info[template_name].good_to_go and
                     restore_info[template_name].vm.klass ==

qubesadmin/tests/__init__.py

@@ -29,6 +29,7 @@ import qubesadmin.app
 class TestVM(object):
     def __init__(self, name, **kwargs):
         self.name = name
+        self.klass = 'TestVM'
         for key, value in kwargs.items():
             setattr(self, key, value)
 

qubesadmin/tests/app.py

@@ -94,7 +94,7 @@ class TC_00_VMCollection(qubesadmin.tests.QubesTestCase):
             b'test-vm2 class=AppVM state=Running\n'
         values = self.app.domains.values()
         for obj in values:
-            self.assertIsInstance(obj, qubesadmin.vm.AppVM)
+            self.assertIsInstance(obj, qubesadmin.vm.QubesVM)
         self.assertEqual(set([vm.name for vm in values]),
             set(['test-vm', 'test-vm2']))
         self.assertAllCalled()
@@ -122,6 +122,17 @@ class TC_00_VMCollection(qubesadmin.tests.QubesTestCase):
         self.assertNotIn('test-non-existent', self.app.domains)
         self.assertAllCalled()
 
+    def test_009_getitem_cache_class(self):
+        self.app.expected_calls[('dom0', 'admin.vm.List', None, None)] = \
+            b'0\x00test-vm class=AppVM state=Running\n'
+        try:
+            vm = self.app.domains['test-vm']
+            self.assertEqual(vm.name, 'test-vm')
+            self.assertEqual(vm.klass, 'AppVM')
+        except KeyError:
+            self.fail('VM not found in collection')
+        self.assertAllCalled()
+
 
 class TC_10_QubesBase(qubesadmin.tests.QubesTestCase):
     def test_010_new_simple(self):
@@ -131,7 +142,7 @@ class TC_10_QubesBase(qubesadmin.tests.QubesTestCase):
             b'0\x00new-vm class=AppVM state=Running\n'
         vm = self.app.add_new_vm('AppVM', 'new-vm', 'red')
         self.assertEqual(vm.name, 'new-vm')
-        self.assertEqual(vm.__class__.__name__, 'AppVM')
+        self.assertEqual(vm.klass, 'AppVM')
         self.assertAllCalled()
 
     def test_011_new_template(self):
@@ -141,7 +152,7 @@ class TC_10_QubesBase(qubesadmin.tests.QubesTestCase):
             b'0\x00new-template class=TemplateVM state=Running\n'
         vm = self.app.add_new_vm('TemplateVM', 'new-template', 'red')
         self.assertEqual(vm.name, 'new-template')
-        self.assertEqual(vm.__class__.__name__, 'TemplateVM')
+        self.assertEqual(vm.klass, 'TemplateVM')
         self.assertAllCalled()
 
     def test_012_new_template_based(self):
@@ -151,7 +162,7 @@ class TC_10_QubesBase(qubesadmin.tests.QubesTestCase):
             b'0\x00new-vm class=AppVM state=Running\n'
         vm = self.app.add_new_vm('AppVM', 'new-vm', 'red', 'some-template')
         self.assertEqual(vm.name, 'new-vm')
-        self.assertEqual(vm.__class__.__name__, 'AppVM')
+        self.assertEqual(vm.klass, 'AppVM')
         self.assertAllCalled()
 
     def test_013_new_objects_params(self):
@@ -165,7 +176,7 @@ class TC_10_QubesBase(qubesadmin.tests.QubesTestCase):
         vm = self.app.add_new_vm(self.app.get_vm_class('AppVM'), 'new-vm',
             self.app.get_label('red'), self.app.domains['some-template'])
         self.assertEqual(vm.name, 'new-vm')
-        self.assertEqual(vm.__class__.__name__, 'AppVM')
+        self.assertEqual(vm.klass, 'AppVM')
         self.assertAllCalled()
 
     def test_014_new_pool(self):
@@ -175,7 +186,7 @@ class TC_10_QubesBase(qubesadmin.tests.QubesTestCase):
             b'0\x00new-vm class=AppVM state=Running\n'
         vm = self.app.add_new_vm('AppVM', 'new-vm', 'red', pool='some-pool')
         self.assertEqual(vm.name, 'new-vm')
-        self.assertEqual(vm.__class__.__name__, 'AppVM')
+        self.assertEqual(vm.klass, 'AppVM')
         self.assertAllCalled()
 
     def test_015_new_pools(self):
@@ -187,7 +198,7 @@ class TC_10_QubesBase(qubesadmin.tests.QubesTestCase):
         vm = self.app.add_new_vm('AppVM', 'new-vm', 'red',
             pools={'private': 'some-pool', 'volatile': 'other-pool'})
         self.assertEqual(vm.name, 'new-vm')
-        self.assertEqual(vm.__class__.__name__, 'AppVM')
+        self.assertEqual(vm.klass, 'AppVM')
         self.assertAllCalled()
 
     def test_016_new_template_based_default(self):
@@ -198,7 +209,7 @@ class TC_10_QubesBase(qubesadmin.tests.QubesTestCase):
         vm = self.app.add_new_vm('AppVM', 'new-vm', 'red',
             template=qubesadmin.DEFAULT)
         self.assertEqual(vm.name, 'new-vm')
-        self.assertEqual(vm.__class__.__name__, 'AppVM')
+        self.assertEqual(vm.klass, 'AppVM')
         self.assertAllCalled()
 
     def test_020_get_label(self):
@@ -422,7 +433,7 @@ class TC_10_QubesBase(qubesadmin.tests.QubesTestCase):
         new_vm = self.app.clone_vm('test-vm', 'new-name',
             new_cls='StandaloneVM')
         self.assertEqual(new_vm.name, 'new-name')
-        self.assertEqual(new_vm.__class__.__name__, 'StandaloneVM')
+        self.assertEqual(new_vm.klass, 'StandaloneVM')
         self.assertAllCalled()
 
     def test_035_clone_fail(self):

qubesadmin/tools/__init__.py

@@ -156,7 +156,7 @@ class VmNameAction(QubesAction):
             namespace.domains = [
                 vm
                 for vm in app.domains
-                if not isinstance(vm, qubesadmin.vm.AdminVM) and
+                if not vm.klass == 'AdminVM' and
                    vm.name not in namespace.exclude
             ]
         else:

qubesadmin/tools/qvm_check.py

@@ -64,8 +64,7 @@ def main(args=None, app=None):
             print_msg(paused, "is paused", "are paused")
         return 0 if paused else 1
     elif args.template:
-        template = [vm for vm in domains if isinstance(vm,
-            qubesadmin.vm.TemplateVM)]
+        template = [vm for vm in domains if vm.klass == 'TemplateVM']
         if args.verbose:
             print_msg(template, "is a template", "are templates")
         return 0 if template else 1

qubesadmin/tools/qvm_ls.py

@@ -214,19 +214,16 @@ class FlagsColumn(Column):
         When it is HVM (optimised VM), the letter is capital.
         '''
 
-        if isinstance(vm, qubesadmin.vm.AdminVM):
-            return '0'
-
-        ret = None
-        # TODO right order, depending on inheritance
-        if isinstance(vm, qubesadmin.vm.TemplateVM):
-            ret = 't'
-        if isinstance(vm, qubesadmin.vm.AppVM):
-            ret = 'a'
-        if isinstance(vm, qubesadmin.vm.StandaloneVM):
-            ret = 's'
-        if isinstance(vm, qubesadmin.vm.DispVM):
-            ret = 'd'
+        type_codes = {
+            'AdminVM': '0',
+            'TemplateVM': 't',
+            'AppVM': 'a',
+            'StandaloneVM': 's',
+            'DispVM': 'd',
+        }
+        ret = type_codes.get(vm.klass, None)
+        if ret == '0':
+            return ret
 
         if ret is not None:
             if getattr(vm, 'virt_mode', 'pv') == 'hvm':
@@ -338,7 +335,7 @@ Column('STATE',
     doc='Current power state.')
 
 Column('CLASS',
-    attr=(lambda vm: type(vm).__name__),
+    attr=(lambda vm: vm.klass),
     doc='Class of the qube.')
 
 

qubesadmin/tools/qvm_start.py

@@ -109,7 +109,7 @@ def get_drive_assignment(app, drive_str):
                 'Existing block device identifier needed when running from '
                 'outside of dom0 (see qvm-block)')
         try:
-            if isinstance(backend_domain, qubesadmin.vm.AdminVM):
+            if backend_domain.klass == 'AdminVM':
                 loop_name = subprocess.check_output(
                     ['sudo', 'losetup', '-f', '--show', ident])
             else:

qubesadmin/tools/qvm_start_gui.py

@@ -296,7 +296,7 @@ class GUILauncher(object):
         '''Send monitor layout to all (running) VMs'''
         monitor_layout = get_monitor_layout()
         for vm in self.app.domains:
-            if isinstance(vm, qubesadmin.vm.AdminVM):
+            if vm.klass == 'AdminVM':
                 continue
             if vm.is_running():
                 if not vm.features.check_with_template('gui', True):
@@ -325,7 +325,7 @@ class GUILauncher(object):
         monitor_layout = get_monitor_layout()
         self.app.domains.clear_cache()
         for vm in self.app.domains:
-            if isinstance(vm, qubesadmin.vm.AdminVM):
+            if vm.klass == 'AdminVM':
                 continue
             if not vm.features.check_with_template('gui', True):
                 continue

qubesadmin/vm/__init__.py

@@ -46,9 +46,10 @@ class QubesVM(qubesadmin.base.PropertyHolder):
 
     firewall = None
 
-    def __init__(self, app, name):
+    def __init__(self, app, name, klass=None):
         super(QubesVM, self).__init__(app, 'admin.vm.property.', name)
         self._volumes = None
+        self._klass = klass
         self.log = logging.getLogger(name)
         self.tags = qubesadmin.tags.Tags(self)
         self.features = qubesadmin.features.Features(self)
@@ -314,6 +315,14 @@ class QubesVM(qubesadmin.base.PropertyHolder):
             e.cmd = command
             raise e
 
+    @property
+    def klass(self):
+        ''' Qube class '''
+        # use cached value if available
+        if self._klass is None:
+            # pylint: disable=no-member
+            self._klass = super(QubesVM, self).klass
+        return self._klass
 
 # pylint: disable=abstract-method
 class AdminVM(QubesVM):