selftests: tc-testing: cleanup on Ctrl-C

Cleanup net namespaces and other resources if we get a SIGINT (Ctrl-C).
As user visible resources are allocated on a per test basis, it's only
required to catch this condition when (possibly) running tests.

So far calling post_suite is enough to free up anything that might
linger.

A missing keyword replacement for nsPlugin is also included.
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20231124154248.315470-5-pctammela@mojatatu.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

tools/testing/selftests/tc-testing/plugin-lib/nsPlugin.py

@@ -78,7 +78,7 @@ class SubPlugin(TdcPlugin):
             print('{}.post_suite'.format(self.sub_class))
 
         # Make sure we don't leak resources
-        cmd = "$IP -a netns del"
+        cmd = self._replace_keywords("$IP -a netns del")
 
         if self.args.verbose > 3:
             print('_exec_cmd:  command "{}"'.format(cmd))

tools/testing/selftests/tc-testing/tdc.py

@@ -1018,7 +1018,11 @@ def main():
     if args.verbose > 2:
         print('args is {}'.format(args))
 
+    try:
         set_operation_mode(pm, parser, args, remaining)
+    except KeyboardInterrupt:
+        # Cleanup on Ctrl-C
+        pm.call_post_suite(None)
 
 if __name__ == "__main__":
     main()