Merge #12904: [qa] Ensure bitcoind processes are cleaned up when tests end

e36a0c0 [qa] Ensure bitcoind processes are cleaned up when tests end (Suhas Daftuar)

Pull request description:

  When tests fail (such as due to a bug in the test, race condition, etc), it's possible that we could follow code paths that bypass our normal node shutdown that occurs in `TestNode.stop_node`.  Add a destructor to `TestNode` that cleans this up.

Tree-SHA512: 72e04bc21462ebd0cb346fd1fe0540da454acfbad41923a0b06ea2317e9045b68e58f9adb02d8200891aca89a9d03a022eb72282aeb31a3b3afe7c6843a4b450

test/functional/feature_help.py

@@ -36,7 +36,11 @@ class HelpTest(BitcoinTestFramework):
         output = self.nodes[0].process.stdout.read()
         assert b'version' in output
         self.log.info("Version text received: {} (...)".format(output[0:60]))
+        # Clean up TestNode state
         self.nodes[0].running = False
+        self.nodes[0].process = None
+        self.nodes[0].rpc_connected = False
+        self.nodes[0].rpc = None
 
 if __name__ == '__main__':
     HelpTest().main()

test/functional/test_framework/test_framework.py

@@ -148,6 +148,8 @@ class BitcoinTestFramework():
             if self.nodes:
                 self.stop_nodes()
         else:
+            for node in self.nodes:
+                node.cleanup_on_exit = False
             self.log.info("Note: bitcoinds were not stopped and may still be running")
 
         if not self.options.nocleanup and not self.options.noshutdown and success != TestStatus.FAILED:

test/functional/test_framework/test_node.py

@@ -88,9 +88,20 @@ class TestNode():
         self.rpc = None
         self.url = None
         self.log = logging.getLogger('TestFramework.node%d' % i)
+        self.cleanup_on_exit = True # Whether to kill the node when this object goes away
 
         self.p2ps = []
 
+    def __del__(self):
+        # Ensure that we don't leave any bitcoind processes lying around after
+        # the test ends
+        if self.process and self.cleanup_on_exit:
+            # Should only happen on test failure
+            # Avoid using logger, as that may have already been shutdown when
+            # this destructor is called.
+            print("Cleaning up leftover process")
+            self.process.kill()
+
     def __getattr__(self, name):
         """Dispatches any unrecognised messages to the RPC connection or a CLI instance."""
         if self.use_cli: