docs: updated the "Read The Docs" documentation (#4728)

* docs: updated the ReadTheDocs documentation to all have links to the examples for consistency

* Update docs/examples/metrics/prometheus-grafana/README.rst

Co-authored-by: Tammy Baylis <[email protected]>

* Added changelog entry as requested in PR feedback

* fixed link to localhost to see the metrics

* just use a plain http link

* Update CHANGELOG.md

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

* fix tox reported issues

* fix capitalization of Prometheus

* Update CHANGELOG.md

---------

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

Author: 3 people

CHANGELOG.md

@@ -12,6 +12,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+- docs: linked the examples with their github source code location and added Prometheus example
+  ([#4728](https://github.com/open-telemetry/opentelemetry-python/pull/4728))
+
 ## Version 1.36.0/0.57b0 (2025-07-29)
 
 - Add missing Prometheus exporter documentation

docs/examples/django/README.rst

@@ -4,7 +4,7 @@ Django Instrumentation
 This shows how to use ``opentelemetry-instrumentation-django`` to automatically instrument a
 Django app.
 
-For more user convenience, a Django app is already provided in this directory.
+The source files of these examples are available :scm_web:`here <docs/examples/django/>`.
 
 Preparation
 -----------

docs/examples/error_handler/README.rst

@@ -6,6 +6,7 @@ Overview
 
 This example shows how to use the global error handler.
 
+The source files of these examples are available :scm_web:`here <docs/examples/error_handler/>`.
 
 Preparation
 -----------

docs/examples/fork-process-model/README.rst

@@ -10,6 +10,8 @@ get around this limitation of the span processor.
 Please see http://bugs.python.org/issue6721 for the problems about Python locks in (multi)threaded
 context with fork.
 
+The source code for the examples with Flask app are available :scm_web:`here <docs/examples/fork-process-model/>`.
+
 Gunicorn post_fork hook
 -----------------------
 
@@ -61,6 +63,3 @@ uWSGI postfork decorator
             OTLPSpanExporter(endpoint="http://localhost:4317")
         )
         trace.get_tracer_provider().add_span_processor(span_processor)
-
-
-The source code for the examples with Flask app are available :scm_web:`here <docs/examples/fork-process-model/>`.

docs/examples/logs/README.rst

@@ -6,6 +6,8 @@ OpenTelemetry Logs SDK
    :mod:`opentelemetry.sdk._logs` are subject to change in minor/patch releases and make no
    backward compatibility guarantees at this time.
 
+The source files of these examples are available :scm_web:`here <docs/examples/logs/>`.
+
 Start the Collector locally to see data being exported. Write the following file:
 
 .. code-block:: yaml

docs/examples/metrics/instruments/README.rst

@@ -1,6 +1,8 @@
 OpenTelemetry Metrics SDK
 =========================
 
+The source files of these examples are available :scm_web:`here <docs/examples/metrics/instruments/>`.
+
 Start the Collector locally to see data being exported. Write the following file:
 
 .. code-block:: yaml

docs/examples/metrics/prometheus-grafana/README.rst

@@ -0,0 +1,63 @@
+Prometheus Instrumentation
+==========================
+
+This shows how to use ``opentelemetry-exporter-prometheus`` to automatically generate Prometheus metrics.
+
+The source files of these examples are available :scm_web:`here <docs/examples/prometheus-grafana/>`.
+
+Preparation
+-----------
+
+This example will be executed in a separate virtual environment:
+
+.. code-block::
+
+    $ mkdir prometheus_auto_instrumentation
+    $ virtualenv prometheus_auto_instrumentation
+    $ source prometheus_auto_instrumentation/bin/activate
+
+
+Installation
+------------
+
+.. code-block::
+
+    $ pip install -r requirements.txt
+
+
+Execution
+---------
+
+.. code-block::
+
+    $ python ./prometheus-monitor.py
+    $ Server is running at http://localhost:8000
+
+Now you can visit http://localhost:8000/metrics to see Prometheus metrics. 
+You should see something like:
+
+.. code-block::
+
+    # HELP python_gc_objects_collected_total Objects collected during gc
+    # TYPE python_gc_objects_collected_total counter
+    python_gc_objects_collected_total{generation="0"} 320.0
+    python_gc_objects_collected_total{generation="1"} 58.0
+    python_gc_objects_collected_total{generation="2"} 0.0
+    # HELP python_gc_objects_uncollectable_total Uncollectable objects found during GC
+    # TYPE python_gc_objects_uncollectable_total counter
+    python_gc_objects_uncollectable_total{generation="0"} 0.0
+    python_gc_objects_uncollectable_total{generation="1"} 0.0
+    python_gc_objects_uncollectable_total{generation="2"} 0.0
+    # HELP python_gc_collections_total Number of times this generation was collected
+    # TYPE python_gc_collections_total counter
+    python_gc_collections_total{generation="0"} 61.0
+    python_gc_collections_total{generation="1"} 5.0
+    python_gc_collections_total{generation="2"} 0.0
+    # HELP python_info Python platform information
+    # TYPE python_info gauge
+    python_info{implementation="CPython",major="3",minor="8",patchlevel="5",version="3.8.5"} 1.0
+    # HELP MyAppPrefix_my_counter_total 
+    # TYPE MyAppPrefix_my_counter_total counter
+    MyAppPrefix_my_counter_total 964.0
+ 
+``MyAppPrefix_my_counter_total`` is the custom counter created in the application with the custom prefix ``MyAppPrefix``.

docs/examples/metrics/prometheus-grafana/prometheus-monitor.py

@@ -18,6 +18,8 @@
 
 my_counter = meter.create_counter("my.counter")
 
+print("Server is running at http://localhost:8000")
+
 while 1:
     my_counter.add(random.randint(1, 10))
     time.sleep(random.random())