Log exceptions (Fixes #447)

Exceptions were just written to stderr but not into logs.

radicale/__init__.py

@@ -28,6 +28,7 @@ should have been included in this package.
 
 import base64
 import contextlib
+import io
 import itertools
 import os
 import posixpath
@@ -130,9 +131,29 @@ class ThreadedHTTPSServer(socketserver.ThreadingMixIn, HTTPSServer):
 
 class RequestHandler(wsgiref.simple_server.WSGIRequestHandler):
     """HTTP requests handler."""
+
+    # These class attributes must be set before creating instance
+    logger = None
+
+    def __init__(self, *args, **kwargs):
+        # Store exception for logging
+        self.error_stream = io.StringIO()
+        super().__init__(*args, **kwargs)
+
+    def get_stderr(self):
+        return self.error_stream
+
     def log_message(self, *args, **kwargs):
         """Disable inner logging management."""
 
+    def handle(self):
+        super().handle()
+        # Log exception
+        error = self.error_stream.getvalue().strip("\n")
+        if error:
+            self.logger.error("An exception occurred during request:\n" +
+                              error)
+
 
 class Application:
     """WSGI application managing collections."""

radicale/__main__.py

@@ -104,7 +104,11 @@ def run():
     if not configuration_found:
         logger.warning("Configuration file '%s' not found" % options.config)
 
+    try:
         serve(configuration, logger)
+    except Exception:
+        logger.exception("An exception occurred during server startup:")
+        exit(1)
 
 
 def serve(configuration, logger):
@@ -175,6 +179,7 @@ def serve(configuration, logger):
     server_class.max_connections = configuration.getint(
         "server", "max_connections")
 
+    RequestHandler.logger = logger
     if not configuration.getboolean("server", "dns_lookup"):
         RequestHandler.address_string = lambda self: self.client_address[0]