Add support for Tornado >= 4.5

Tornado 4.5 changed request routing in a breaking way. This adds support
for the new behavior while preserving existing behavior for older
versions of Tornado.

sprockets_influxdb.py

@@ -30,6 +30,12 @@ except ImportError:  # pragma: no cover
     logging.critical('Could not import Tornado')
     concurrent, httpclient, ioloop = None, None, None
 
+try:
+    from tornado import routing
+except ImportError:  # Not needed for Tornado<4.5
+    pass
+
+
 version_info = (2, 1, 0)
 __version__ = '.'.join(str(v) for v in version_info)
 __all__ = ['__version__', 'version_info', 'add_measurement', 'flush',
@@ -100,15 +106,46 @@ class InfluxDBMixin(object):
             handler = '{}.{}'.format(self.__module__, self.__class__.__name__)
             self.influxdb.set_tags({'handler': handler,
                                     'method': request.method})
-            for host, handlers in application.handlers:
-                if not host.match(request.host):
-                    continue
+
+            pattern = None
+            if hasattr(application, 'handlers'):
+                pattern = self._get_path_pattern_tornado4()
+            else:
+                pattern = self._get_path_pattern_tornado45()
+            if pattern:
+                endpoint = pattern.rstrip('$')
+            else:
+                LOGGER.warning('Unable to determine routing pattern')
+                endpoint = request.path
+            self.influxdb.set_tags({'endpoint': endpoint})
+
+    def _get_path_pattern_tornado4(self):
+        """Return the path pattern used when routing a request. (Tornado<4.5)
+
+        :rtype: str
+        """
+        for host, handlers in self.application.handlers:
+            if host.match(self.request.host):
                 for handler in handlers:
-                    match = handler.regex.match(request.path)
-                    if match:
-                        self.influxdb.set_tag(
-                            'endpoint', handler.regex.pattern.rstrip('$'))
-                        break
+                    if handler.regex.match(self.request.path):
+                        return handler.regex.pattern
+
+    def _get_path_pattern_tornado45(self, router=None):
+        """Return the path pattern used when routing a request. (Tornado>=4.5)
+
+        :param tornado.routing.Router router: (Optional) The router to scan.
+            Defaults to the application's router.
+
+        :rtype: str
+        """
+        if router is None:
+            router = self.application.default_router
+        for rule in router.rules:
+            if rule.matcher.match(self.request) is not None:
+                if isinstance(rule.matcher, routing.PathMatches):
+                    return rule.matcher.regex.pattern
+                elif isinstance(rule.target, routing.Router):
+                    return self._get_path_pattern_tornado45(rule.target)
 
     def on_finish(self):
         if _enabled:

tests/mixin_tests.py

@@ -1,5 +1,9 @@
+import mock
 import socket
 import time
+import unittest
+
+import tornado
 
 from . import base
 
@@ -66,3 +70,65 @@ class MeasurementTestCase(base.AsyncServerTestCase):
         self.assertEqual(measurement.tags['method'], 'GET')
         self.assertEqual(measurement.tags['endpoint'], '/param/(?P<id>\d+)')
         self.assertEqual(measurement.fields['content_length'], 13)
+
+    def test_measurement_with_specific_host(self):
+        self.application.add_handlers(
+            'some_host', [('/host/(?P<id>\d+)', base.ParamRequestHandler)])
+        result = self.fetch('/host/100', headers={'Host': 'some_host'})
+        self.assertEqual(result.code, 200)
+        measurement = self.get_measurement()
+        self.assertIsNotNone(measurement)
+        self.assertEqual(measurement.db, 'database-name')
+        self.assertEqual(measurement.name, 'my-service')
+        self.assertEqual(measurement.tags['status_code'], '200')
+        self.assertEqual(measurement.tags['method'], 'GET')
+        self.assertEqual(measurement.tags['endpoint'], '/host/(?P<id>\d+)')
+        self.assertEqual(measurement.fields['content_length'], 13)
+
+    @unittest.skipIf(tornado.version_info >= (4, 5),
+                     'legacy routing removed in 4.5')
+    @mock.patch(
+        'sprockets_influxdb.InfluxDBMixin._get_path_pattern_tornado45')
+    @mock.patch(
+        'sprockets_influxdb.InfluxDBMixin._get_path_pattern_tornado4')
+    def test_mesurement_with_ambiguous_route_4(self, mock_4, mock_45):
+        mock_4.return_value = None
+        mock_45.return_value = None
+
+        result = self.fetch('/param/100')
+        self.assertEqual(result.code, 200)
+        measurement = self.get_measurement()
+        self.assertIsNotNone(measurement)
+        self.assertEqual(measurement.db, 'database-name')
+        self.assertEqual(measurement.name, 'my-service')
+        self.assertEqual(measurement.tags['status_code'], '200')
+        self.assertEqual(measurement.tags['method'], 'GET')
+        self.assertEqual(measurement.tags['endpoint'], '/param/100')
+        self.assertEqual(measurement.fields['content_length'], 13)
+
+        self.assertEqual(1, mock_4.call_count)
+        self.assertEqual(0, mock_45.call_count)
+
+    @unittest.skipIf(tornado.version_info < (4, 5),
+                     'routing module introduced in tornado 4.5')
+    @mock.patch(
+        'sprockets_influxdb.InfluxDBMixin._get_path_pattern_tornado45')
+    @mock.patch(
+        'sprockets_influxdb.InfluxDBMixin._get_path_pattern_tornado4')
+    def test_mesurement_with_ambiguous_route_45(self, mock_4, mock_45):
+        mock_4.return_value = None
+        mock_45.return_value = None
+
+        result = self.fetch('/param/100')
+        self.assertEqual(result.code, 200)
+        measurement = self.get_measurement()
+        self.assertIsNotNone(measurement)
+        self.assertEqual(measurement.db, 'database-name')
+        self.assertEqual(measurement.name, 'my-service')
+        self.assertEqual(measurement.tags['status_code'], '200')
+        self.assertEqual(measurement.tags['method'], 'GET')
+        self.assertEqual(measurement.tags['endpoint'], '/param/100')
+        self.assertEqual(measurement.fields['content_length'], 13)
+
+        self.assertEqual(0, mock_4.call_count)
+        self.assertEqual(1, mock_45.call_count)