asyncio: fix environment variables not appearing in docs (#4261)

* asyncio: fix environment variables not in docs

Fix the docstrings in environment_variables.py so they are correctly
picked up by Sphinx autodoc for Read the Docs.

Previously the docstrings were placed above the variable assignments,
which Sphinx cannot parse. Moved them below and added the
required '.. envvar::' directives, consistent with how other
packages (e.g. opentelemetry-instrumentation) document their
environment variables.

Fixes #4256

* Fix typo from 'determines' to 'determine'

* Apply suggestion from @xrmx

* asyncio: move environment_variables docs to __init__ module docstring for sphinx

* asyncio: keep envvar docs in environment_variables.py with module-level docstring

---------

Co-authored-by: Riccardo Magliocchetti <[email protected]>

Author: srikaaviya

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"
 )