Add HTTPX hook access to request and response objects

.changelog/4564.added

@@ -0,0 +1 @@
+`opentelemetry-instrumentation-httpx`: add request and response objects to hooks

CHANGELOG.md

@@ -12,7 +12,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## Unreleased
 
 ### Added
-
 - Add `BaggageLogProcessor` to `opentelemetry-processor-baggage`
   ([#4371](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/4371))
 - `opentelemetry-instrumentation-system-metrics`: Add support for `process.disk.io` metric in system-metrics instrumentation

instrumentation/opentelemetry-instrumentation-httpx/README.rst

@@ -130,7 +130,38 @@ and right before the span is finished while processing a response.
 
 .. note::
 
-    The request hook receives the raw arguments provided to the transport layer. The response hook receives the raw return values from the transport layer.
+    The request hook receives the raw arguments provided to the transport layer.
+    The response hook receives the raw return values from the transport layer.
+    For HTTPX versions that pass ``httpx.Request`` and ``httpx.Response``
+    objects to the transport layer, these original objects are available as
+    ``request.request`` and ``response.response``. Older HTTPX transport APIs may
+    set these attributes to ``None``.
+
+Request and response bodies can contain sensitive data. If you log or add them
+to spans, make sure to redact and limit the captured content.
+
+.. code-block:: python
+
+    import logging
+
+    logger = logging.getLogger(__name__)
+
+    def response_hook(span, request, response):
+        if request.request is not None:
+            logger.debug("HTTPX request body: %r", request.request.content)
+
+        if response.response is not None:
+            logger.debug("HTTPX response body: %r", response.response.read())
+
+    async def async_response_hook(span, request, response):
+        if request.request is not None:
+            logger.debug("HTTPX request body: %r", request.request.content)
+
+        if response.response is not None:
+            logger.debug(
+                "HTTPX response body: %r",
+                await response.response.aread(),
+            )
 
 The hooks can be configured as follows: