Add SIGTERM handling to geographic gatherer

pytroll_collectors/geographic_gatherer.py

@@ -25,6 +25,7 @@
 """Geographic segment gathering."""
 
 import logging
+import signal
 import time
 
 from configparser import NoOptionError, ConfigParser
@@ -56,6 +57,8 @@ def __init__(self, opts):
         self.triggers = []
         self.return_status = 0
 
+        self._sigterm_caught = False
+
         self._clean_config()
         self._setup_publisher()
         try:
@@ -103,8 +106,10 @@ def _setup_triggers(self):
 
     def run(self):
         """Run granule triggers."""
+        signal.signal(signal.SIGTERM, self._handle_sigterm)
         try:
             while True:
+                self._check_sigterm()
                 time.sleep(1)
                 for trigger in self.triggers:
                     if not trigger.is_alive():
@@ -119,6 +124,18 @@ def run(self):
 
         return self.return_status
 
+    def _handle_sigterm(self, signum, frame):
+        logger.info("Caught SIGTERM, shutting down when all collections are finished.")
+        self._sigterm_caught = True
+
+    def _check_sigterm(self):
+        if self._sigterm_caught:
+            for t in self.triggers:
+                for c in t.collectors:
+                    if c.granules:
+                        return
+            raise KeyboardInterrupt("No ongoing collections.")
+
     def stop(self):
         """Stop the gatherer."""
         logger.info('Ending publication the gathering of granules...')

pytroll_collectors/tests/test_geographic_gatherer.py

@@ -527,3 +527,27 @@ def test_full_pass(self, sub_factory, monkeypatch, tmp_tle):
             assert snd_msg.data == expected_msg.data
         finally:
             gatherer.stop()
+
+
+def test_sigterm(tmp_config_file, tmp_config_parser):
+    """Test that SIGTERM signal is handled."""
+    import os
+    import signal
+    import time
+    from multiprocessing import Process
+
+    from pytroll_collectors.geographic_gatherer import GeographicGatherer
+
+    with open(tmp_config_file, mode="w") as fp:
+        tmp_config_parser.write(fp)
+
+    opts = arg_parse(["-c", "minimal_config", "-p", "40000", "-n", "false", "-i", "localhost:12345",
+                     str(tmp_config_file)])
+    gatherer = GeographicGatherer(opts)
+    proc = Process(target=gatherer.run)
+    proc.start()
+    time.sleep(1)
+    os.kill(proc.pid, signal.SIGTERM)
+    proc.join()
+
+    assert proc.exitcode == 0