Add SIGTERM handling in web.run_app

CHANGES.rst

@@ -9,7 +9,7 @@ Changes
 - Retain method attributes (e.g. :code:`__doc__`) when registering synchronous
   handlers for resources. #1953
 
--
+- Added signal TERM handling in `run_app` to gracefully exit #1932
 
 - Fix websocket issues caused by frame fragmentation. #1962
 

CONTRIBUTORS.txt

@@ -37,6 +37,7 @@ Brett Cannon
 Brian C. Lane
 Brian Muller
 Carl George
+Cecile Tonglet
 Chien-Wei Huang
 Chih-Yuan Chen
 Chris AtLee

aiohttp/web.py

@@ -1,5 +1,6 @@
 import asyncio
 import os
+import signal
 import socket
 import stat
 import sys
@@ -318,10 +319,18 @@ def __repr__(self):
         return "<Application 0x{:x}>".format(id(self))
 
 
+class GracefulExit(SystemExit):
+    code = 1
+
+
+def raise_graceful_exit():
+    raise GracefulExit()
+
+
 def run_app(app, *, host=None, port=None, path=None, sock=None,
             shutdown_timeout=60.0, ssl_context=None,
             print=print, backlog=128, access_log_format=None,
-            access_log=access_logger, loop=None):
+            access_log=access_logger, handle_signals=True, loop=None):
     """Run an app locally"""
     user_supplied_loop = loop is not None
     if loop is None:
@@ -414,12 +423,19 @@ def run_app(app, *, host=None, port=None, path=None, sock=None,
         asyncio.gather(*server_creations, loop=loop)
     )
 
-    print("======== Running on {} ========\n"
-          "(Press CTRL+C to quit)".format(', '.join(uris)))
+    if handle_signals:
+        try:
+            loop.add_signal_handler(signal.SIGINT, raise_graceful_exit)
+            loop.add_signal_handler(signal.SIGTERM, raise_graceful_exit)
+        except NotImplementedError:  # pragma: no cover
+            # add_signal_handler is not implemented on Windows
+            pass
 
     try:
+        print("======== Running on {} ========\n"
+              "(Press CTRL+C to quit)".format(', '.join(uris)))
         loop.run_forever()
-    except KeyboardInterrupt:  # pragma: no cover
+    except (GracefulExit, KeyboardInterrupt):  # pragma: no cover
         pass
     finally:
         server_closures = []

docs/web_reference.rst

@@ -2085,10 +2085,11 @@ Utilities
 
 
 .. function:: run_app(app, *, host=None, port=None, path=None, \
-                      loop=None, shutdown_timeout=60.0, \
+                      sock=None, shutdown_timeout=60.0, \
                       ssl_context=None, print=print, backlog=128, \
                       access_log_format=None, \
-                      access_log=aiohttp.log.access_logger)
+                      access_log=aiohttp.log.access_logger, \
+                      handle_signals=True, loop=None)
 
    A utility function for running an application, serving it until
    keyboard interrupt and performing a
@@ -2155,6 +2156,9 @@ Utilities
                              :ref:`aiohttp-logging-access-log-format-spec`
                              for details.
 
+   :param bool handle_signals: override signal TERM handling to gracefully
+                               exit the application.
+
    :param loop: an *event loop* used for running the application
                 (``None`` by default).
 

tests/test_run_app.py

@@ -1,8 +1,12 @@
 import asyncio
 import contextlib
 import os
+import platform
+import signal
 import socket
 import ssl
+import subprocess
+import sys
 from io import StringIO
 from unittest import mock
 from uuid import uuid4
@@ -46,6 +50,11 @@ def skip_if_no_dict(loop):
         pytest.skip("can not override loop attributes")
 
 
+def skip_if_on_windows():
+    if platform.system() == "Windows":
+        pytest.skip("the test is not valid for Windows")
+
+
 def test_run_app_http(loop, mocker):
     skip_if_no_dict(loop)
 
@@ -505,3 +514,35 @@ def test_run_app_multiple_preexisting_sockets(loop, mocker):
         app.startup.assert_called_once_with()
         assert "http://0.0.0.0:{}".format(port1) in printed.getvalue()
         assert "http://0.0.0.0:{}".format(port2) in printed.getvalue()
+
+
+_script_test_signal = """
+from aiohttp import web
+
+app = web.Application()
+web.run_app(app, host=())
+"""
+
+
+def test_sigint(loop, mocker):
+    skip_if_on_windows()
+
+    proc = subprocess.Popen([sys.executable, "-u", "-c", _script_test_signal],
+                            stdout=subprocess.PIPE)
+    for line in proc.stdout:
+        if line.startswith(b"======== Running on"):
+            break
+    proc.send_signal(signal.SIGINT)
+    assert proc.wait() == 0
+
+
+def test_sigterm(loop, mocker):
+    skip_if_on_windows()
+
+    proc = subprocess.Popen([sys.executable, "-u", "-c", _script_test_signal],
+                            stdout=subprocess.PIPE)
+    for line in proc.stdout:
+        if line.startswith(b"======== Running on"):
+            break
+    proc.terminate()
+    assert proc.wait() == 0