Detect kill signal and log it.

arenaclient/client.py

@@ -13,7 +13,7 @@
 import aiohttp
 import psutil
 from .match.matches import MatchSourceFactory, MatchSource
-from .utl import Utl
+from .utl import Utl, KillSignalDetector
 from .match.result import Result
 
 
@@ -265,6 +265,8 @@ async def main(self, match: MatchSource.Match):
         bot2_process = None
         pids = []
         try:
+            kill_signal_detector = KillSignalDetector()  # for exiting gracefully when terminated
+
             self._ws, self._session = await connect(address=self.address, headers=self.headers)
 
             if await self.connected():
@@ -442,6 +444,11 @@ async def main(self, match: MatchSource.Match):
                     pass
 
             if not result.has_result():
+                # todo: implemented now simply to log for testing.
+                # todo: if this works, don't submit the result.
+                if kill_signal_detector.signal_received:
+                    self._utl.printout(f"{kill_signal_detector.signal_name} signal received.")
+
                 result.parse_result(init_error(match))
             self._utl.pid_cleanup(pids)
             return result

arenaclient/utl.py

@@ -208,3 +208,35 @@ def clean_dir(self, directory):
                 os.unlink(file_path)
             elif os.path.isdir(file_path):
                 shutil.rmtree(file_path)
+
+
+# How to process SIGTERM signal gracefully?
+# https://stackoverflow.com/questions/18499497/how-to-process-sigterm-signal-gracefully
+import signal
+import time
+
+
+class KillSignalDetector:
+    signal_received = False
+    signal_name = "none"
+
+    def __init__(self):
+        signal.signal(signal.SIGINT, self.exit_gracefully_sigint)
+        signal.signal(signal.SIGTERM, self.exit_gracefully_sigterm)
+
+    def exit_gracefully_sigint(self, *args):
+        self.signal_name = "SIGINT"
+        self.signal_received = True
+
+    def exit_gracefully_sigterm(self, *args):
+        self.signal_name = "SIGTERM"
+        self.signal_received = True
+
+
+# if __name__ == '__main__':
+#     killer = GracefulKiller()
+#     while not killer.kill_now:
+#         time.sleep(1)
+#         print("doing something in a loop ...")
+#
+#     print("End of the program. I was killed gracefully :)")