use contextvars backport for aiohttp and sanic support in py3.6 (#293)

* use contextvars backport

* use var for contextvars backport detection

* fix: Fix logic for contextvar check

* fix: Formatting

* fix: Workaround for asyncio.create_task

* fix: Linters

Author: Anton Spitsyn

sentry_sdk/integrations/aiohttp.py

@@ -6,7 +6,11 @@
 from sentry_sdk.integrations import Integration
 from sentry_sdk.integrations.logging import ignore_logger
 from sentry_sdk.integrations._wsgi_common import _filter_headers
-from sentry_sdk.utils import capture_internal_exceptions, event_from_exception
+from sentry_sdk.utils import (
+    capture_internal_exceptions,
+    event_from_exception,
+    HAS_REAL_CONTEXTVARS,
+)
 
 import asyncio
 from aiohttp.web import Application, HTTPException  # type: ignore
@@ -27,11 +31,12 @@ class AioHttpIntegration(Integration):
     @staticmethod
     def setup_once():
         # type: () -> None
-        if sys.version_info < (3, 7):
+        if not HAS_REAL_CONTEXTVARS:
             # We better have contextvars or we're going to leak state between
             # requests.
             raise RuntimeError(
-                "The aiohttp integration for Sentry requires Python 3.7+"
+                "The aiohttp integration for Sentry requires Python 3.7+ "
+                " or aiocontextvars package"
             )
 
         ignore_logger("aiohttp.server")
@@ -61,7 +66,10 @@ async def inner():
 
                     return response
 
-            return await asyncio.create_task(inner())
+            # Explicitly wrap in task such that current contextvar context is
+            # copied. Just doing `return await inner()` will leak scope data
+            # between requests.
+            return await asyncio.get_event_loop().create_task(inner())
 
         Application._handle = sentry_app_handle
 

sentry_sdk/integrations/sanic.py

@@ -4,7 +4,11 @@
 
 from sentry_sdk._compat import urlparse, reraise
 from sentry_sdk.hub import Hub
-from sentry_sdk.utils import capture_internal_exceptions, event_from_exception
+from sentry_sdk.utils import (
+    capture_internal_exceptions,
+    event_from_exception,
+    HAS_REAL_CONTEXTVARS,
+)
 from sentry_sdk.integrations import Integration
 from sentry_sdk.integrations._wsgi_common import RequestExtractor, _filter_headers
 from sentry_sdk.integrations.logging import ignore_logger
@@ -34,10 +38,13 @@ class SanicIntegration(Integration):
     @staticmethod
     def setup_once():
         # type: () -> None
-        if sys.version_info < (3, 7):
-            # Sanic is async. We better have contextvars or we're going to leak
-            # state between requests.
-            raise RuntimeError("The sanic integration for Sentry requires Python 3.7+")
+        if not HAS_REAL_CONTEXTVARS:
+            # We better have contextvars or we're going to leak state between
+            # requests.
+            raise RuntimeError(
+                "The sanic integration for Sentry requires Python 3.7+ "
+                " or aiocontextvars package"
+            )
 
         # Sanic 0.8 and older creates a logger named "root" and puts a
         # stringified version of every exception in there (without exc_info),

sentry_sdk/utils.py

@@ -868,9 +868,16 @@ def realign_remark(remark):
     )
 
 
+HAS_REAL_CONTEXTVARS = True
+
 try:
     from contextvars import ContextVar  # type: ignore
+
+    if not PY2 and sys.version_info < (3, 7):
+        import aiocontextvars  # type: ignore # noqa
 except ImportError:
+    HAS_REAL_CONTEXTVARS = False
+
     from threading import local
 
     class ContextVar(object):  # type: ignore

test-requirements.txt

@@ -4,4 +4,4 @@ pytest-xdist==1.23.0
 tox==3.7.0
 Werkzeug==0.14.1
 pytest-localserver==0.4.1
-pytest-cov==2.6.0
+pytest-cov==2.6.0

tests/integrations/aiohttp/test_aiohttp.py

@@ -28,7 +28,7 @@ async def hello(request):
     assert request["env"] == {"REMOTE_ADDR": "127.0.0.1"}
     assert request["method"] == "GET"
     assert request["query_string"] == ""
-    assert request["url"] == f"http://{host}/"
+    assert request["url"] == "http://{host}/".format(host=host)
     assert request["headers"] == {
         "Accept": "*/*",
         "Accept-Encoding": "gzip, deflate",

tests/integrations/sanic/test_sanic.py

@@ -1,3 +1,5 @@
+import sys
+
 import random
 import asyncio
 
@@ -140,7 +142,9 @@ async def task(i):
 
         await app.handle_request(
             request.Request(
-                url_bytes=f"http://localhost/context-check/{i}".encode("ascii"),
+                url_bytes="http://localhost/context-check/{i}".format(i=i).encode(
+                    "ascii"
+                ),
                 headers={},
                 version="1.1",
                 method="GET",
@@ -156,7 +160,12 @@ async def task(i):
     async def runner():
         await asyncio.gather(*(task(i) for i in range(1000)))
 
-    asyncio.run(runner())
+    if sys.version_info < (3, 7):
+        loop = asyncio.new_event_loop()
+        asyncio.set_event_loop(loop)
+        loop.run_until_complete(runner())
+    else:
+        asyncio.run(runner())
 
     with configure_scope() as scope:
         assert not scope._tags

tox.ini

@@ -20,7 +20,7 @@ envlist =
 
     {pypy,py2.7,py3.5,py3.6,py3.7,py3.8}-flask-{1.0,0.11,0.12,dev}
 
-    py3.7-sanic-0.8
+    {py3.5,py3.6,py3.7}-sanic-0.8
 
     {pypy,py2.7,py3.5,py3.6,py3.7,py3.8}-celery-{4.1,4.2}
     {pypy,py2.7}-celery-3
@@ -62,6 +62,7 @@ deps =
     flask-dev: git+https://github.com/pallets/flask.git#egg=flask
 
     sanic-0.8: sanic>=0.8,<0.9
+    {py3.5,py3.6}-sanic-0.8: aiocontextvars==0.2.1
     sanic: aiohttp
 
     celery-3: Celery>=3.1,<4.0