tests: collect detailed diagnostics on failure

Help debugging test failures by collecting detailed information on
failure. It will be logger to the standard logger, which will end up
either on stderr or in journalctl.

qubes/tests/integ/network.py

@@ -18,7 +18,7 @@
 # You should have received a copy of the GNU Lesser General Public
 # License along with this library; if not, see <https://www.gnu.org/licenses/>.
 #
-
+import contextlib
 from distutils import spawn
 
 import asyncio
@@ -87,6 +87,32 @@ class VmNetworkingMixin(object):
 
         self.configure_netvm()
 
+    def _run_cmd_and_log_output(self, vm, cmd):
+        """Used in tearDown to collect more info"""
+        if not vm.is_running():
+            return
+        with contextlib.suppress(subprocess.CalledProcessError):
+            output = self.loop.run_until_complete(
+                self.testnetvm.run_for_stdio(cmd, user='root'))
+            self.log.error('{}: {}: {}'.format(vm.name, cmd, output))
+
+    def tearDown(self):
+        # collect more info on failure
+        if self._outcome and not self._outcome.success:
+            for vm in (self.testnetvm, self.testvm1, getattr(self, 'proxy', None)):
+                if vm is None:
+                    continue
+                self._run_cmd_and_log_output(vm, 'ip a')
+                self._run_cmd_and_log_output(vm, 'ip r')
+                self._run_cmd_and_log_output(vm, 'iptables -vnL')
+                self._run_cmd_and_log_output(vm, 'iptables -vnL -t nat')
+                self._run_cmd_and_log_output(vm, 'nft list table qubes-firewall')
+                self._run_cmd_and_log_output(vm, 'systemctl --no-pager status qubes-firewall')
+                self._run_cmd_and_log_output(vm, 'systemctl --no-pager status qubes-iptables')
+                self._run_cmd_and_log_output(vm, 'systemctl --no-pager status xendriverdomain')
+
+        super(VmNetworkingMixin, self).tearDown()
+
 
     def configure_netvm(self):
         '''

qubes/tests/integ/network_ipv6.py

@@ -43,6 +43,19 @@ class VmIPv6NetworkingMixin(VmNetworkingMixin):
         self.ping6_ip = self.ping6_cmd.format(target=self.test_ip6)
         self.ping6_name = self.ping6_cmd.format(target=self.test_name)
 
+    def tearDown(self):
+        # collect more info on failure (ipv4 info collected in parent)
+        if self._outcome and not self._outcome.success:
+            for vm in (self.testnetvm, self.testvm1, getattr(self, 'proxy', None)):
+                if vm is None:
+                    continue
+                self._run_cmd_and_log_output(vm, 'ip -6 r')
+                self._run_cmd_and_log_output(vm, 'ip6tables -vnL')
+                self._run_cmd_and_log_output(vm, 'ip6tables -vnL -t nat')
+                self._run_cmd_and_log_output(vm, 'nft list table ip6 qubes-firewall')
+
+        super().tearDown()
+
     def configure_netvm(self):
         '''
         :type self: qubes.tests.SystemTestCase | VmIPv6NetworkingMixin