tests/functional/test_vnc: Skip test if VNC support is not available

These tests currently fail if VNC support has not been compiled into
the QEMU binary. Let's add some checks to skip the tests in that
case instead.

Message-ID: <[email protected]>
Reviewed-by: Daniel P. Berrangé <[email protected]>
Signed-off-by: Thomas Huth <[email protected]>

Author: huth

tests/functional/test_vnc.py

@@ -12,6 +12,7 @@
 
 import socket
 from typing import List
+from qemu.machine.machine import VMLaunchFailure
 
 from qemu_test import QemuSystemTest
 from qemu_test.ports import Ports
@@ -32,7 +33,14 @@ class Vnc(QemuSystemTest):
     def test_no_vnc_change_password(self):
         self.vm.add_args('-nodefaults', '-S')
         self.vm.launch()
-        self.assertFalse(self.vm.qmp('query-vnc')['return']['enabled'])
+
+        query_vnc_response = self.vm.qmp('query-vnc')
+        if 'error' in query_vnc_response:
+            self.assertEqual(query_vnc_response['error']['class'],
+                             'CommandNotFound')
+            self.skipTest('VNC support not available')
+        self.assertFalse(query_vnc_response['return']['enabled'])
+
         set_password_response = self.vm.qmp('change-vnc-password',
                                             password='new_password')
         self.assertIn('error', set_password_response)
@@ -41,9 +49,19 @@ def test_no_vnc_change_password(self):
         self.assertEqual(set_password_response['error']['desc'],
                          'Could not set password')
 
+    def launch_guarded(self):
+        try:
+            self.vm.launch()
+        except VMLaunchFailure as excp:
+            if "-vnc: invalid option" in excp.output:
+                self.skipTest("VNC support not available")
+            else:
+                self.log.info("unhandled launch failure: %s", excp.output)
+                raise excp
+
     def test_change_password_requires_a_password(self):
         self.vm.add_args('-nodefaults', '-S', '-vnc', ':1,to=999')
-        self.vm.launch()
+        self.launch_guarded()
         self.assertTrue(self.vm.qmp('query-vnc')['return']['enabled'])
         set_password_response = self.vm.qmp('change-vnc-password',
                                             password='new_password')
@@ -55,7 +73,7 @@ def test_change_password_requires_a_password(self):
 
     def test_change_password(self):
         self.vm.add_args('-nodefaults', '-S', '-vnc', ':1,to=999,password=on')
-        self.vm.launch()
+        self.launch_guarded()
         self.assertTrue(self.vm.qmp('query-vnc')['return']['enabled'])
         self.vm.cmd('change-vnc-password',
                     password='new_password')
@@ -66,7 +84,7 @@ def do_test_change_listen(self, a, b, c):
         self.assertFalse(check_connect(c))
 
         self.vm.add_args('-nodefaults', '-S', '-vnc', f'{VNC_ADDR}:{a - 5900}')
-        self.vm.launch()
+        self.launch_guarded()
         self.assertEqual(self.vm.qmp('query-vnc')['return']['service'], str(a))
         self.assertTrue(check_connect(a))
         self.assertFalse(check_connect(b))