asyncio: fix environment variables not appearing in docs

CHANGELOG.md

@@ -59,6 +59,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#4139](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/4139))
 
 ### Fixed
+
+- `opentelemetry-instrumentation-asyncio`: Fix environment variables not appearing in Read the Docs documentation
+  ([#4256](https://github.com/open-telemetry/opentelemetry-python-contrib/issues/4256))
 - `opentelemetry-instrumentation-mysql`: Refactor MySQL integration test mocks to use concrete DBAPI connection attributes, reducing noisy attribute type warnings.
   ([#4116](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/4116))
 - `opentelemetry-instrumentation-cassandra`: Use `_instruments_any` instead of `_instruments` for driver dependencies so that having either `cassandra-driver` or `scylla-driver` installed is sufficient

docs/instrumentation/asyncio/asyncio.rst

@@ -5,3 +5,8 @@ OpenTelemetry asyncio Instrumentation
     :members:
     :undoc-members:
     :show-inheritance:
+
+.. automodule:: opentelemetry.instrumentation.asyncio.environment_variables
+    :members:
+    :undoc-members:
+    :show-inheritance:

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

@@ -79,7 +79,6 @@ def func():
 * asyncio.process.duration (seconds) - Duration of asyncio process
 * asyncio.process.count (count) - Number of asyncio process
 
-
 API
 ---
 """

instrumentation/opentelemetry-instrumentation-asyncio/src/opentelemetry/instrumentation/asyncio/environment_variables.py

@@ -13,23 +13,27 @@
 # limitations under the License.
 
 """
-Enter the names of the coroutines to be traced through the environment variable below, separated by commas.
+.. envvar:: OTEL_PYTHON_ASYNCIO_COROUTINE_NAMES_TO_TRACE
+
+    Enter the names of the coroutines to be traced through the environment variable below, separated by commas.
+
+.. envvar:: OTEL_PYTHON_ASYNCIO_FUTURE_TRACE_ENABLED
+
+    To determine whether the tracing feature for Future of Asyncio in Python is enabled or not.
+
+.. envvar:: OTEL_PYTHON_ASYNCIO_TO_THREAD_FUNCTION_NAMES_TO_TRACE
+
+    Enter the names of the functions to be traced through the environment variable below, separated by commas.
 """
 
 OTEL_PYTHON_ASYNCIO_COROUTINE_NAMES_TO_TRACE = (
     "OTEL_PYTHON_ASYNCIO_COROUTINE_NAMES_TO_TRACE"
 )
 
-"""
-To determines whether the tracing feature for Future of Asyncio in Python is enabled or not.
-"""
 OTEL_PYTHON_ASYNCIO_FUTURE_TRACE_ENABLED = (
     "OTEL_PYTHON_ASYNCIO_FUTURE_TRACE_ENABLED"
 )
 
-"""
-Enter the names of the functions to be traced through the environment variable below, separated by commas.
-"""
 OTEL_PYTHON_ASYNCIO_TO_THREAD_FUNCTION_NAMES_TO_TRACE = (
     "OTEL_PYTHON_ASYNCIO_TO_THREAD_FUNCTION_NAMES_TO_TRACE"
 )