Add quit event, used for getting locust's exit code just before exit (#…

…2049)

examples/test_data_management.py

@@ -10,7 +10,8 @@
 # 6. Test run stopping
 # 7. User stop
 # 8. Test run stop
-# 9. (not shown in this example) Locust quit
+# 9. Locust quitting
+# 10. Locust quit
 #
 # try it out by running:
 #  locust -f test_data_management.py --headless -u 2 -t 5
@@ -61,6 +62,11 @@ def _(environment, **_kwargs):
         ).json()["data"]
 
 
+@events.quit.add_listener
+def _(environment, exit_code, **kwargs):
+    print(f"Locust has shut down with code {exit_code}")
+
+
 @events.test_stopping.add_listener
 def _(environment, **_kwargs):
     print("stopping test run")

locust/event.py

@@ -149,13 +149,22 @@ class Events:
 
     quitting: EventHook
     """
-    Fired when the locust process is exiting
+    Fired when the locust process is exiting.
 
     Event arguments:
 
     :param environment: Environment instance
     """
 
+    quit: EventHook
+    """
+    Fired after quitting events, just before process is exited.
+
+    Event arguments:
+
+    :param exit_code: Exit code for process
+    """
+
     init: EventHook
     """
     Fired when Locust is started, once the Environment instance and locust runner instance

locust/main.py

@@ -425,16 +425,17 @@ def shutdown():
         environment.events.quitting.fire(environment=environment, reverse=True)
 
         # determine the process exit code
-        if log.unhandled_greenlet_exception:
-            code = 2
-        elif environment.process_exit_code is not None:
+        if environment.process_exit_code is not None:
             code = environment.process_exit_code
         elif len(runner.errors) or len(runner.exceptions):
             code = options.exit_code_on_error
+        elif log.unhandled_greenlet_exception:
+            code = 2
         else:
             code = 0
 
         logger.info(f"Shutting down (exit code {code})")
+
         if stats_printer_greenlet is not None:
             stats_printer_greenlet.kill(block=False)
         if headless_master_greenlet is not None:
@@ -448,6 +449,7 @@ def shutdown():
             print_percentile_stats(runner.stats)
             print_error_report(runner.stats)
 
+        environment.events.quit.fire(exit_code=code)
         sys.exit(code)
 
     # install SIGTERM handler

locust/test/test_main.py

@@ -266,6 +266,9 @@ def test_custom_exit_code(self):
             @events.quitting.add_listener
             def _(environment, **kw):
                 environment.process_exit_code = 42
+            @events.quit.add_listener
+            def _(exit_code, **kw):
+                print(f"Exit code in quit event {exit_code}")
             class TestUser(User):
                 wait_time = constant(3)
                 @task
@@ -279,9 +282,11 @@ def my_task(self):
             proc.send_signal(signal.SIGTERM)
             stdout, stderr = proc.communicate()
             stderr = stderr.decode("utf-8")
+            stdout = stdout.decode("utf-8")
             self.assertIn("Starting web interface at", stderr)
             self.assertIn("Starting Locust", stderr)
             self.assertIn("Shutting down (exit code 42)", stderr)
+            self.assertIn("Exit code in quit event 42", stdout)
             self.assertEqual(42, proc.returncode)
 
     def test_webserver(self):