Falcon 3 support (#644)

Author: adriangb

CHANGELOG.md

@@ -28,6 +28,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `opentelemetry-instrumentation-urllib3` Updated `_RequestHookT` with two additional fields - the request body and the request headers
 ([#660](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/660))
 
+### Changed
+- Tests for Falcon 3 support
+  ([#644](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/644))
+
 ### Added
 
 - `opentelemetry-instrumentation-urllib3`, `opentelemetry-instrumentation-requests`

instrumentation/README.md

@@ -11,7 +11,7 @@
 | [opentelemetry-instrumentation-dbapi](./opentelemetry-instrumentation-dbapi) | dbapi |
 | [opentelemetry-instrumentation-django](./opentelemetry-instrumentation-django) | django >= 1.10 |
 | [opentelemetry-instrumentation-elasticsearch](./opentelemetry-instrumentation-elasticsearch) | elasticsearch >= 2.0 |
-| [opentelemetry-instrumentation-falcon](./opentelemetry-instrumentation-falcon) | falcon ~= 2.0 |
+| [opentelemetry-instrumentation-falcon](./opentelemetry-instrumentation-falcon) | falcon >= 2.0.0, < 4.0.0 |
 | [opentelemetry-instrumentation-fastapi](./opentelemetry-instrumentation-fastapi) | fastapi ~= 0.58 |
 | [opentelemetry-instrumentation-flask](./opentelemetry-instrumentation-flask) | flask >= 1.0, < 3.0 |
 | [opentelemetry-instrumentation-grpc](./opentelemetry-instrumentation-grpc) | grpcio ~= 1.27 |

instrumentation/opentelemetry-instrumentation-falcon/README.rst

@@ -9,8 +9,6 @@ OpenTelemetry Falcon Tracing
 This library builds on the OpenTelemetry WSGI middleware to track web requests
 in Falcon applications.
 
-Currently, only Falcon v2 is supported.
-
 Installation
 ------------
 

instrumentation/opentelemetry-instrumentation-falcon/src/opentelemetry/instrumentation/falcon/__init__.py

@@ -126,6 +126,13 @@ def response_hook(span, req, resp):
 
 _response_propagation_setter = FuncSetter(falcon.Response.append_header)
 
+if hasattr(falcon, "App"):
+    # Falcon 3
+    _instrument_app = "App"
+else:
+    # Falcon 2
+    _instrument_app = "API"
+
 
 class FalconInstrumentor(BaseInstrumentor):
     # pylint: disable=protected-access,attribute-defined-outside-init
@@ -138,14 +145,16 @@ def instrumentation_dependencies(self) -> Collection[str]:
         return _instruments
 
     def _instrument(self, **kwargs):
-        self._original_falcon_api = falcon.API
-        falcon.API = partial(_InstrumentedFalconAPI, **kwargs)
+        self._original_falcon_api = getattr(falcon, _instrument_app)
+        setattr(
+            falcon, _instrument_app, partial(_InstrumentedFalconAPI, **kwargs)
+        )
 
     def _uninstrument(self, **kwargs):
-        falcon.API = self._original_falcon_api
+        setattr(falcon, _instrument_app, self._original_falcon_api)
 
 
-class _InstrumentedFalconAPI(falcon.API):
+class _InstrumentedFalconAPI(getattr(falcon, _instrument_app)):
     def __init__(self, *args, **kwargs):
         # inject trace middleware
         middlewares = kwargs.pop("middleware", [])
@@ -169,6 +178,15 @@ def __init__(self, *args, **kwargs):
         self._excluded_urls = get_excluded_urls("FALCON")
         super().__init__(*args, **kwargs)
 
+    def _handle_exception(
+        self, req, resp, ex, params
+    ):  # pylint: disable=C0103
+        # Falcon 3 does not execute middleware within the context of the exception
+        # so we capture the exception here and save it into the env dict
+        _, exc, _ = exc_info()
+        req.env[_ENVIRON_EXC] = exc
+        return super()._handle_exception(req, resp, ex, params)
+
     def __call__(self, env, start_response):
         # pylint: disable=E1101
         if self._excluded_urls.url_disabled(env.get("PATH_INFO", "/")):
@@ -193,7 +211,6 @@ def __call__(self, env, start_response):
         env[_ENVIRON_ACTIVATION_KEY] = activation
 
         def _start_response(status, response_headers, *args, **kwargs):
-            otel_wsgi.add_response_attributes(span, status, response_headers)
             response = start_response(
                 status, response_headers, *args, **kwargs
             )
@@ -264,29 +281,32 @@ def process_response(
         if resource is None:
             status = "404"
             reason = "NotFound"
-
-        exc_type, exc, _ = exc_info()
-        if exc_type and not req_succeeded:
-            if "HTTPNotFound" in exc_type.__name__:
-                status = "404"
-                reason = "NotFound"
+        else:
+            if _ENVIRON_EXC in req.env:
+                exc = req.env[_ENVIRON_EXC]
+                exc_type = type(exc)
             else:
-                status = "500"
-                reason = "{}: {}".format(exc_type.__name__, exc)
+                exc_type, exc = None, None
+            if exc_type and not req_succeeded:
+                if "HTTPNotFound" in exc_type.__name__:
+                    status = "404"
+                    reason = "NotFound"
+                else:
+                    status = "500"
+                    reason = "{}: {}".format(exc_type.__name__, exc)
 
         status = status.split(" ")[0]
         try:
             status_code = int(status)
-        except ValueError:
-            pass
-        finally:
             span.set_attribute(SpanAttributes.HTTP_STATUS_CODE, status_code)
             span.set_status(
                 Status(
                     status_code=http_status_to_status_code(status_code),
                     description=reason,
                 )
             )
+        except ValueError:
+            pass
 
         propagator = get_global_response_propagator()
         if propagator:

instrumentation/opentelemetry-instrumentation-falcon/src/opentelemetry/instrumentation/falcon/package.py

@@ -13,4 +13,4 @@
 # limitations under the License.
 
 
-_instruments = ("falcon ~= 2.0",)
+_instruments = ("falcon >= 2.0.0, < 4.0.0",)

instrumentation/opentelemetry-instrumentation-falcon/tests/app.py

@@ -34,7 +34,12 @@ def on_get(self, req, resp):
 
 
 def make_app():
-    app = falcon.API()
+    if hasattr(falcon, "App"):
+        # Falcon 3
+        app = falcon.App()
+    else:
+        # Falcon 2
+        app = falcon.API()
     app.add_route("/hello", HelloWorldResource())
     app.add_route("/ping", HelloWorldResource())
     app.add_route("/error", ErrorResource())

instrumentation/opentelemetry-instrumentation-falcon/tests/test_falcon.py

@@ -78,14 +78,19 @@ def test_head(self):
         self._test_method("HEAD")
 
     def _test_method(self, method):
-        self.client().simulate_request(method=method, path="/hello")
+        self.client().simulate_request(
+            method=method, path="/hello", remote_addr="127.0.0.1"
+        )
         spans = self.memory_exporter.get_finished_spans()
         self.assertEqual(len(spans), 1)
         span = spans[0]
         self.assertEqual(
             span.name, "HelloWorldResource.on_{0}".format(method.lower())
         )
         self.assertEqual(span.status.status_code, StatusCode.UNSET)
+        self.assertEqual(
+            span.status.description, None,
+        )
         self.assertSpanHasAttributes(
             span,
             {
@@ -105,12 +110,15 @@ def _test_method(self, method):
         self.memory_exporter.clear()
 
     def test_404(self):
-        self.client().simulate_get("/does-not-exist")
+        self.client().simulate_get("/does-not-exist", remote_addr="127.0.0.1")
         spans = self.memory_exporter.get_finished_spans()
         self.assertEqual(len(spans), 1)
         span = spans[0]
         self.assertEqual(span.name, "HTTP GET")
         self.assertEqual(span.status.status_code, StatusCode.ERROR)
+        self.assertEqual(
+            span.status.description, "NotFound",
+        )
         self.assertSpanHasAttributes(
             span,
             {
@@ -129,7 +137,7 @@ def test_404(self):
 
     def test_500(self):
         try:
-            self.client().simulate_get("/error")
+            self.client().simulate_get("/error", remote_addr="127.0.0.1")
         except NameError:
             pass
         spans = self.memory_exporter.get_finished_spans()

pytest.ini

@@ -2,3 +2,4 @@
 addopts = -rs -v
 log_cli = true
 log_cli_level = warning
+testpaths = instrumentation/opentelemetry-instrumentation-falcon/tests/

tox.ini

@@ -38,8 +38,8 @@ envlist =
     pypy3-test-instrumentation-elasticsearch{2,5,6}
 
     ; opentelemetry-instrumentation-falcon
-    py3{4,5,6,7,8,9}-test-instrumentation-falcon
-    pypy3-test-instrumentation-falcon
+    py3{4,5,6,7,8,9}-test-instrumentation-falcon{2,3}
+    pypy3-test-instrumentation-falcon{2,3}
 
     ; opentelemetry-instrumentation-fastapi
     ; fastapi only supports 3.6 and above.
@@ -175,6 +175,8 @@ deps =
   ; FIXME: Elasticsearch >=7 causes CI workflow tests to hang, see open-telemetry/opentelemetry-python-contrib#620
   ; elasticsearch7: elasticsearch-dsl>=7.0,<8.0
   ; elasticsearch7: elasticsearch>=7.0,<8.0
+  falcon2: falcon >=2.0.0,<3.0.0
+  falcon3: falcon >=3.0.0,<4.0.0
   sqlalchemy11: sqlalchemy>=1.1,<1.2
   sqlalchemy14: aiosqlite
   sqlalchemy14: sqlalchemy~=1.4
@@ -193,7 +195,7 @@ changedir =
   test-instrumentation-dbapi: instrumentation/opentelemetry-instrumentation-dbapi/tests
   test-instrumentation-django: instrumentation/opentelemetry-instrumentation-django/tests
   test-instrumentation-elasticsearch{2,5,6}: instrumentation/opentelemetry-instrumentation-elasticsearch/tests
-  test-instrumentation-falcon: instrumentation/opentelemetry-instrumentation-falcon/tests
+  test-instrumentation-falcon{2,3}: instrumentation/opentelemetry-instrumentation-falcon/tests
   test-instrumentation-fastapi: instrumentation/opentelemetry-instrumentation-fastapi/tests
   test-instrumentation-flask: instrumentation/opentelemetry-instrumentation-flask/tests
   test-instrumentation-urllib: instrumentation/opentelemetry-instrumentation-urllib/tests
@@ -236,16 +238,16 @@ commands_pre =
 
   grpc: pip install {toxinidir}/instrumentation/opentelemetry-instrumentation-grpc[test]
 
-  falcon,flask,django,pyramid,tornado,starlette,fastapi,aiohttp,asgi,requests,urllib,urllib3,wsgi: pip install {toxinidir}/util/opentelemetry-util-http[test]
-  wsgi,falcon,flask,django,pyramid: pip install {toxinidir}/instrumentation/opentelemetry-instrumentation-wsgi[test]
+  falcon{2,3},flask,django,pyramid,tornado,starlette,fastapi,aiohttp,asgi,requests,urllib,urllib3,wsgi: pip install {toxinidir}/util/opentelemetry-util-http[test]
+  wsgi,falcon{2,3},flask,django,pyramid: pip install {toxinidir}/instrumentation/opentelemetry-instrumentation-wsgi[test]
   asgi,starlette,fastapi: pip install {toxinidir}/instrumentation/opentelemetry-instrumentation-asgi[test]
 
   asyncpg: pip install {toxinidir}/instrumentation/opentelemetry-instrumentation-asyncpg[test]
 
   boto: pip install {toxinidir}/instrumentation/opentelemetry-instrumentation-botocore[test]
   boto: pip install {toxinidir}/instrumentation/opentelemetry-instrumentation-boto[test]
 
-  falcon: pip install {toxinidir}/instrumentation/opentelemetry-instrumentation-falcon[test]
+  falcon{2,3}: pip install {toxinidir}/instrumentation/opentelemetry-instrumentation-falcon[test]
 
   flask: pip install {toxinidir}/instrumentation/opentelemetry-instrumentation-flask[test]