Add pre and post instrument entrypoints (open-telemetry#1983)

ocelotl · owais · web-flow · commit 08392c80b80d · 2021-09-09T22:46:29.000+05:30
* Add pre and post instrument entry points Fixes open-telemetry#1982 Co-authored-by: Owais Lone <owais@users.noreply.github.com>
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -14,6 +14,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [1.5.0-0.24b0](https://github.com/open-telemetry/opentelemetry-python/releases/tag/v1.5.0-0.24b0) - 2021-08-26
 
 
+- Add pre and post instrumentation entry points
+  ([#1983](https://github.com/open-telemetry/opentelemetry-python/pull/1983))
 - Fix documentation on well known exporters and variable OTEL_TRACES_EXPORTER which were misnamed
   ([#2023](https://github.com/open-telemetry/opentelemetry-python/pull/2023))
 - `opentelemetry-sdk` `get_aggregated_resource()` returns default resource and service name
diff --git a/opentelemetry-instrumentation/src/opentelemetry/instrumentation/auto_instrumentation/sitecustomize.py b/opentelemetry-instrumentation/src/opentelemetry/instrumentation/auto_instrumentation/sitecustomize.py
@@ -60,6 +60,9 @@ def _load_instrumentors(distro):
         # to handle users entering "requests , flask" or "requests, flask" with spaces
         package_to_exclude = [x.strip() for x in package_to_exclude]
 
+    for entry_point in iter_entry_points("opentelemetry_pre_instrument"):
+        entry_point.load()()
+
     for entry_point in iter_entry_points("opentelemetry_instrumentor"):
         if entry_point.name in package_to_exclude:
             logger.debug(
@@ -84,6 +87,9 @@ def _load_instrumentors(distro):
             logger.exception("Instrumenting of %s failed", entry_point.name)
             raise exc
 
+    for entry_point in iter_entry_points("opentelemetry_post_instrument"):
+        entry_point.load()()
+
 
 def _load_configurators():
     configured = None
