Allow users to override SIGHUP signal

README.md

@@ -9,12 +9,11 @@
 
 # Socket Log Receiver
 
-`socket_log_receiver` is a light-weight socket log receiver. It runs
-as a server and aggregates messages from multi-process application via
-socket and logs to a single file. Python's `logging` package does not
-support logging to a single file from multiple processes. By pointing
-`SocketHandler` to `socket_log_receiver`, the multi-process
-application can log to a single file.
+`socket_log_receiver` is a light-weight socket log receiving server.
+It aggregates messages from multi-process application via socket and
+logs to a single file. The service is intended to be used with
+Python's `logging` package, which does not support multi-process
+writes to a single file.
 
 
 ## Installation
@@ -26,13 +25,15 @@ $ pip install socket-log-receiver
 
 ## Basic Usage
 
-The receiver service should be run as a service.
+The receiver service should be run as a service:
 
 ``` bash
 $ python -m socket_log_receiver  # as a module
 $ log_receiver                   # as a command-line program
 ```
 
+By default, the receiver service starts listening on `localhost:9020`.
+
 In the application, use `SocketHandler` to send logs to the receiver
 service.
 
@@ -46,6 +47,19 @@ logging.root.addHandler(handler)            # add the socket handler to the root
 This way, the root logger sends logging messages to the receiver service.
 
 
+### Undefined Signal
+
+The receiver service's configuration is managed by
+[resconfig](https://github.com/okomestudio/resconfig). By default, the
+dynamic configuration update is trigged by `SIGHUP`. Some systems
+might not make this signal available, in which case you could use a
+different signal for the trigger using the command-line option, e.g.
+
+``` bash
+$ log_receiver --reload-signal SIGUSR2
+```
+
+
 ## Development
 
 ```bash
@@ -57,5 +71,5 @@ $ pre-commit install
 ### Running Tests
 
 ``` bash
-$ python setup.py tests
+$ pytest
 ```

src/socket_log_receiver/__main__.py

@@ -8,12 +8,16 @@
 from .receivers import serve
 
 
-def main():
+def main(argv=None):
     p = ArgumentParser()
     p.add_argument("--conf")
-    p.add_argument("--reload-signal", default="SIGHUP")
+    p.add_argument(
+        "--reload-signal",
+        default="SIGHUP",
+        help="Signal to reload config.",
+    )
     config.add_arguments_to_argparse(p)
-    args = p.parse_args()
+    args = p.parse_args(argv)
     config.prepare_from_argparse(args, config_file_arg="conf")
     config.register("log", configure_logging)
     config.register("receiver", serve)

src/socket_log_receiver/config.py

@@ -1,7 +1,6 @@
 import logging
 import logging.handlers
 import signal
-import platform
 
 from resconfig import ResConfig
 
@@ -28,17 +27,13 @@
 def handler(*args, **kwargs):
     config.load()
 
-if platform.system() != 'Linux':
-    signal.SIGHUP = 1
 
-def reloader(reload_signal):
-    # reloader_signal = config.get("reloader.signal", "SIGHUP")
-    print("FF", reload_signal)
-    logging.info("HERE")
+def reloader(reload_signal: str):
+    """Configure config reloader."""
     try:
         sig = getattr(signal, reload_signal)
-    except AttributeError:
+        assert isinstance(sig, signal.Signals)
+    except (AttributeError, AssertionError):
         raise RuntimeError(f"Signal '{ reload_signal }' not recognized")
-    logging.info("%s will reload config", sig)
     signal.signal(sig, handler)
     logging.info("%s will reload config", sig)

tests/socket_log_receiver/test_main.py

@@ -1,5 +1,7 @@
 import sys
 
+import pytest
+
 import socket_log_receiver.__main__ as main
 from socket_log_receiver.config import config
 
@@ -10,7 +12,35 @@
 
 
 class TestMain:
-    def test(self):
+    def test_default(self):
         with patch.object(config, "load") as load:
             main.main()
-            load.assert_called()
+
+        load.assert_called()
+
+    def test_reload_signal_default(self):
+        argv = None  # argv from command-line
+
+        with patch.object(config, "load") as load:
+            main.main(argv)
+
+        load.assert_called()
+
+    def test_reload_signal_override(self):
+        available_signal = "SIGTERM"
+        argv = ["--reload-signal", available_signal]
+
+        with patch.object(config, "load") as load:
+            main.main(argv)
+
+        load.assert_called()
+
+    def test_reload_signal_override_with_bad_signal(self):
+        bad_signal = "SIGFOO"
+        argv = ["--reload-signal", bad_signal]
+
+        with patch.object(config, "load"):
+            with pytest.raises(RuntimeError) as exc:
+                main.main(argv)
+
+        assert f"Signal '{ bad_signal }' not recognized" in str(exc)