chore(integrations): move fastapi,flask,flask_cache,futures to intern…

…al (#10127)

- Moves all integration internals in ddtrace/contrib/(integration name)/
to ddtrace/contrib/internal/(integration name)/ for fasapi, flask,
flask_cache, and futures
- Ensures ddtrace/contrib/(integration name)/ and
ddtrace/contrib/(integration name)/ continue to expose the same
functions, classes, imports, and module level variables (via from
..internal.integration.module import * imports).
- Log a deprecation warning if internal modules in
ddtrace/contrib/(integration name)/ and ddtrace/contrib/(integration
name)/. Only patch and unpack methods should be exposed by these
packages.
- #9996

## Checklist
- [x] PR author has checked that all the criteria below are met
- The PR description includes an overview of the change
- The PR description articulates the motivation for the change
- The change includes tests OR the PR description describes a testing
strategy
- The PR description notes risks associated with the change, if any
- Newly-added code is easy to change
- The change follows the [library release note
guidelines](https://ddtrace.readthedocs.io/en/stable/releasenotes.html)
- The change includes or references documentation updates if necessary
- Backport labels are set (if
[applicable](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting))

## Reviewer Checklist
- [ ] Reviewer has checked that all the criteria below are met 
- Title is accurate
- All changes are related to the pull request's stated goal
- Avoids breaking
[API](https://ddtrace.readthedocs.io/en/stable/versioning.html#interfaces)
changes
- Testing strategy adequately addresses listed risks
- Newly-added code is easy to change
- Release note makes sense to a user of the library
- If necessary, author has acknowledged and discussed the performance
implications of this PR as reported in the benchmarks PR comment
- Backport labels are set in a manner that is consistent with the
[release branch maintenance
policy](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting)

---------

Co-authored-by: Emmett Butler <[email protected]>

ddtrace/contrib/fastapi/__init__.py

@@ -57,8 +57,12 @@
 
 with require_modules(required_modules) as missing_modules:
     if not missing_modules:
-        from .patch import get_version
-        from .patch import patch
-        from .patch import unpatch
+        # Required to allow users to import from `ddtrace.contrib.fastapi.patch` directly
+        from . import patch as _  # noqa: F401, I001
+
+        # Expose public methods
+        from ..internal.fastapi.patch import get_version
+        from ..internal.fastapi.patch import patch
+        from ..internal.fastapi.patch import unpatch
 
         __all__ = ["patch", "unpatch", "get_version"]

ddtrace/contrib/fastapi/patch.py

@@ -1,103 +1,4 @@
-import os
+from ..internal.fastapi.patch import *  # noqa: F401,F403
 
-import fastapi
-import fastapi.routing
 
-from ddtrace import Pin
-from ddtrace import config
-from ddtrace.contrib.asgi.middleware import TraceMiddleware
-from ddtrace.contrib.starlette.patch import _trace_background_tasks
-from ddtrace.contrib.starlette.patch import traced_handler
-from ddtrace.internal.logger import get_logger
-from ddtrace.internal.schema import schematize_service_name
-from ddtrace.internal.utils.wrappers import unwrap as _u
-from ddtrace.vendor.wrapt import ObjectProxy
-from ddtrace.vendor.wrapt import wrap_function_wrapper as _w
-
-
-log = get_logger(__name__)
-
-config._add(
-    "fastapi",
-    dict(
-        _default_service=schematize_service_name("fastapi"),
-        request_span_name="fastapi.request",
-        distributed_tracing=True,
-        trace_query_string=None,  # Default to global config
-        _trace_asgi_websocket=os.getenv("DD_ASGI_TRACE_WEBSOCKET", default=False),
-    ),
-)
-
-
-def get_version():
-    # type: () -> str
-    return getattr(fastapi, "__version__", "")
-
-
-def wrap_middleware_stack(wrapped, instance, args, kwargs):
-    return TraceMiddleware(app=wrapped(*args, **kwargs), integration_config=config.fastapi)
-
-
-async def traced_serialize_response(wrapped, instance, args, kwargs):
-    """Wrapper for fastapi.routing.serialize_response function.
-
-    This function is called on all non-Response objects to
-    convert them to a serializable form.
-
-    This is the wrapper which calls ``jsonable_encoder``.
-
-    This function does not do the actual encoding from
-    obj -> json string  (e.g. json.dumps()). That is handled
-    by the Response.render function.
-
-    DEV: We do not wrap ``jsonable_encoder`` because it calls
-    itself recursively, so there is a chance the overhead
-    added by creating spans will be higher than desired for
-    the result.
-    """
-    pin = Pin.get_from(fastapi)
-    if not pin or not pin.enabled():
-        return await wrapped(*args, **kwargs)
-
-    with pin.tracer.trace("fastapi.serialize_response"):
-        return await wrapped(*args, **kwargs)
-
-
-def patch():
-    if getattr(fastapi, "_datadog_patch", False):
-        return
-
-    fastapi._datadog_patch = True
-    Pin().onto(fastapi)
-    _w("fastapi.applications", "FastAPI.build_middleware_stack", wrap_middleware_stack)
-    _w("fastapi.routing", "serialize_response", traced_serialize_response)
-
-    if not isinstance(fastapi.BackgroundTasks.add_task, ObjectProxy):
-        _w("fastapi", "BackgroundTasks.add_task", _trace_background_tasks(fastapi))
-
-    # We need to check that Starlette instrumentation hasn't already patched these
-    if not isinstance(fastapi.routing.APIRoute.handle, ObjectProxy):
-        _w("fastapi.routing", "APIRoute.handle", traced_handler)
-
-    if not isinstance(fastapi.routing.Mount.handle, ObjectProxy):
-        _w("starlette.routing", "Mount.handle", traced_handler)
-
-
-def unpatch():
-    if not getattr(fastapi, "_datadog_patch", False):
-        return
-
-    fastapi._datadog_patch = False
-
-    _u(fastapi.applications.FastAPI, "build_middleware_stack")
-    _u(fastapi.routing, "serialize_response")
-
-    # We need to check that Starlette instrumentation hasn't already unpatched these
-    if isinstance(fastapi.routing.APIRoute.handle, ObjectProxy):
-        _u(fastapi.routing.APIRoute, "handle")
-
-    if isinstance(fastapi.routing.Mount.handle, ObjectProxy):
-        _u(fastapi.routing.Mount, "handle")
-
-    if isinstance(fastapi.BackgroundTasks.add_task, ObjectProxy):
-        _u(fastapi.BackgroundTasks, "add_task")
+# TODO: deprecate and remove this module

ddtrace/contrib/flask/__init__.py

@@ -104,10 +104,9 @@ def index():
 with require_modules(required_modules) as missing_modules:
     if not missing_modules:
         # DEV: We do this so we can `@mock.patch('ddtrace.contrib.flask._patch.<func>')` in tests
-        from . import patch as _patch
-
-        patch = _patch.patch
-        unpatch = _patch.unpatch
-        get_version = _patch.get_version
+        from . import patch as _  # noqa: F401, I001
+        from ..internal.flask.patch import patch
+        from ..internal.flask.patch import unpatch
+        from ..internal.flask.patch import get_version
 
         __all__ = ["patch", "unpatch", "get_version"]