feat(integration): Add Falcon integration

sentry_sdk/integrations/falcon.py

@@ -0,0 +1,171 @@
+from __future__ import absolute_import
+
+import falcon  # type: ignore
+import falcon.api_helpers  # type: ignore
+from sentry_sdk.hub import Hub
+from sentry_sdk.integrations import Integration
+from sentry_sdk.integrations._wsgi_common import RequestExtractor
+from sentry_sdk.integrations.wsgi import SentryWsgiMiddleware
+from sentry_sdk.utils import capture_internal_exceptions, event_from_exception
+
+if False:
+    from typing import Any
+    from typing import Callable
+    from typing import Dict
+
+
+class FalconRequestExtractor(RequestExtractor):
+    def env(self):
+        return self.request.env
+
+    def cookies(self):
+        return self.request.cookies
+
+    def form(self):
+        return None  # No such concept in Falcon
+
+    def files(self):
+        return None  # No such concept in Falcon
+
+    def raw_data(self):
+        # As request data can only be read once we won't make this available
+        # to Sentry. Just send back a dummy string in case there was a
+        # content length.
+        # TODO(jmagnusson): Figure out if there's a way to support this
+        content_length = self.content_length()
+        if content_length > 0:
+            return "[REQUEST_CONTAINING_RAW_DATA]"
+        else:
+            return None
+
+    def json(self):
+        try:
+            return self.request.media
+        except falcon.errors.HTTPBadRequest:
+            # NOTE(jmagnusson): We return `falcon.Request._media` here because
+            # falcon 1.4 doesn't do proper type checking in
+            # `falcon.Request.media`. This has been fixed in 2.0.
+            # Relevant code: https://github.com/falconry/falcon/blob/1.4.1/falcon/request.py#L953
+            return self.request._media
+
+
+class SentryFalconMiddleware(object):
+    """Captures exceptions in Falcon requests and send to Sentry"""
+
+    def process_request(self, req, resp, *args, **kwargs):
+        hub = Hub.current
+        integration = hub.get_integration(FalconIntegration)
+        if integration is None:
+            return
+
+        with hub.configure_scope() as scope:
+            scope._name = "falcon"
+            scope.add_event_processor(_make_request_event_processor(req, integration))
+
+
+class FalconIntegration(Integration):
+    identifier = "falcon"
+
+    transaction_style = None
+
+    def __init__(self, transaction_style="uri_template"):
+        # type: (str) -> None
+        TRANSACTION_STYLE_VALUES = ("uri_template", "path")
+        if transaction_style not in TRANSACTION_STYLE_VALUES:
+            raise ValueError(
+                "Invalid value for transaction_style: %s (must be in %s)"
+                % (transaction_style, TRANSACTION_STYLE_VALUES)
+            )
+        self.transaction_style = transaction_style
+
+    @staticmethod
+    def setup_once():
+        # type: () -> None
+        _patch_wsgi_app()
+        _patch_handle_exception()
+        _patch_prepare_middleware()
+
+
+def _patch_wsgi_app():
+    original_wsgi_app = falcon.API.__call__
+
+    def sentry_patched_wsgi_app(self, env, start_response):
+        hub = Hub.current
+        integration = hub.get_integration(FalconIntegration)
+        if integration is None:
+            return original_wsgi_app(self, env, start_response)
+
+        sentry_wrapped = SentryWsgiMiddleware(
+            lambda envi, start_resp: original_wsgi_app(self, envi, start_resp)
+        )
+
+        return sentry_wrapped(env, start_response)
+
+    falcon.API.__call__ = sentry_patched_wsgi_app
+
+
+def _patch_handle_exception():
+    original_handle_exception = falcon.API._handle_exception
+
+    def sentry_patched_handle_exception(self, *args):
+        # NOTE(jmagnusson): falcon 2.0 changed falcon.API._handle_exception
+        # method signature from `(ex, req, resp, params)` to
+        # `(req, resp, ex, params)`
+        if isinstance(args[0], Exception):
+            ex = args[0]
+        else:
+            ex = args[2]
+
+        was_handled = original_handle_exception(self, *args)
+
+        hub = Hub.current
+        integration = hub.get_integration(FalconIntegration)
+
+        if integration is not None and not _is_falcon_http_error(ex):
+            event, hint = event_from_exception(
+                ex,
+                client_options=hub.client.options,
+                mechanism={"type": "falcon", "handled": False},
+            )
+            hub.capture_event(event, hint=hint)
+
+        return was_handled
+
+    falcon.API._handle_exception = sentry_patched_handle_exception
+
+
+def _patch_prepare_middleware():
+    original_prepare_middleware = falcon.api_helpers.prepare_middleware
+
+    def sentry_patched_prepare_middleware(
+        middleware=None, independent_middleware=False
+    ):
+        hub = Hub.current
+        integration = hub.get_integration(FalconIntegration)
+        if integration is not None:
+            middleware = [SentryFalconMiddleware()] + (middleware or [])
+        return original_prepare_middleware(middleware, independent_middleware)
+
+    falcon.api_helpers.prepare_middleware = sentry_patched_prepare_middleware
+
+
+def _is_falcon_http_error(ex):
+    return isinstance(ex, (falcon.HTTPError, falcon.http_status.HTTPStatus))
+
+
+def _make_request_event_processor(req, integration):
+    # type: (falcon.Request, FalconIntegration) -> Callable
+
+    def inner(event, hint):
+        # type: (Dict[str, Any], Dict[str, Any]) -> Dict[str, Any]
+        if integration.transaction_style == "uri_template":
+            event["transaction"] = req.uri_template
+        elif integration.transaction_style == "path":
+            event["transaction"] = req.path
+
+        with capture_internal_exceptions():
+            FalconRequestExtractor(req).extract_into_event(event)
+
+        return event
+
+    return inner

setup.py

@@ -25,6 +25,7 @@
     extras_require={
         "flask": ["flask>=0.8", "blinker>=1.1"],
         "bottle": ["bottle>=0.12.13"],
+        "falcon": ["falcon>=1.4"],
     },
     classifiers=[
         "Development Status :: 5 - Production/Stable",