BUG#35733608: Server stmt spans right after the cnx aren't related to the connector's cnx span

Server statement spans immediately after the connection
aren't related to the connector's connection span.

When connecting to a MySQL server via connector-python,
and executing operations, where OpenTelemetry is enabled
on both sides, the server-side statement spans generated
during the connector's connection span aren't related to it.

With this patch, all spans generated on the server side
at connection time get related to the connector's
connection span.

Change-Id: I817b8b8d8c8bfa172ee234b258d3da0d3079cdbf

Author: oscpache

CHANGES.txt

@@ -15,6 +15,7 @@ v8.2.0
 - WL#15623: Improve the authentication module
 - WL#15218: Support WebAuthn authentication
 - BUG#35755852: Django config raise_on_warnings is ignored without isolation_level
+- BUG#35733608: Server stmt spans right after the cnx aren't related to the connector's cnx span
 - BUG#35547876: C/Python 8.1.0 type check build fails in the pb2 branch
 - BUG#35544123: Kerberos unit tests configuration is outdated
 - BUG#35503506: Query on information_schema.columns returns bytes

lib/mysql/connector/opentelemetry/instrumentation.py

@@ -8,6 +8,7 @@
 import re
 
 from abc import ABC, abstractmethod
+from contextlib import nullcontext
 from typing import TYPE_CHECKING, Any, Callable, Collection, Dict, Optional, Union
 
 # pylint: disable=cyclic-import
@@ -187,7 +188,22 @@ def set_connection_span_attrs(
     cnx_span.set_attributes(attrs)
 
 
-def instrument_execution(
+def with_connection_span_attached(method: Callable) -> Callable:
+    """Attach the connection span while executing a connection method."""
+
+    def wrapper(
+        cnx: Union["MySQLConnection", "CMySQLConnection"], *args: Any, **kwargs: Any
+    ) -> Any:
+        """Context propagation decorator."""
+        with trace.use_span(
+            cnx._span, end_on_exit=False
+        ) if cnx._span and cnx._span.is_recording() else nullcontext():
+            return method(cnx, *args, **kwargs)
+
+    return wrapper
+
+
+def _instrument_execution(
     query_method: Callable,
     tracer: trace.Tracer,
     connection_span_link: trace.Link,
@@ -288,7 +304,7 @@ def __init__(
 
     def execute(self, *args: Any, **kwargs: Any) -> Any:
         """Instruments execute method."""
-        return instrument_execution(
+        return _instrument_execution(
             self._wrapped.execute,
             self._tracer,
             self._connection_span_link,
@@ -299,7 +315,7 @@ def execute(self, *args: Any, **kwargs: Any) -> Any:
 
     def executemany(self, *args: Any, **kwargs: Any) -> Any:
         """Instruments executemany method."""
-        return instrument_execution(
+        return _instrument_execution(
             self._wrapped.executemany,
             self._tracer,
             self._connection_span_link,
@@ -310,7 +326,7 @@ def executemany(self, *args: Any, **kwargs: Any) -> Any:
 
     def callproc(self, *args: Any, **kwargs: Any) -> Any:
         """Instruments callproc method."""
-        return instrument_execution(
+        return _instrument_execution(
             self._wrapped.callproc,
             self._tracer,
             self._connection_span_link,
@@ -332,15 +348,20 @@ def __init__(self, wrapped: Union["MySQLConnection", "CMySQLConnection"]) -> Non
         _ = self._wrapped.sql_mode
 
     def cursor(self, *args: Any, **kwargs: Any) -> TracedMySQLCursor:
-        """Wraps the cursor object."""
+        """Wraps the object method."""
         return TracedMySQLCursor(
             wrapped=self._wrapped.cursor(*args, **kwargs),
             tracer=self._tracer,
             connection_span=self._span,
         )
 
+    @with_connection_span_attached
+    def cmd_change_user(self, *args: Any, **kwargs: Any) -> Any:
+        """Wraps the object method."""
+        return self._wrapped.cmd_change_user(*args, **kwargs)
+
 
-def instrument_connect(
+def _instrument_connect(
     connect: Callable[
         ..., Union["MySQLConnection", "CMySQLConnection", "PooledMySQLConnection"]
     ],
@@ -376,19 +397,21 @@ def wrapper(
         )
         kwargs[OPTION_CNX_TRACER] = tracer
 
-        # Add basic net information.
-        set_connection_span_attrs(None, kwargs[OPTION_CNX_SPAN], kwargs)
+        # attach connection span
+        with trace.use_span(kwargs[OPTION_CNX_SPAN], end_on_exit=False) as cnx_span:
+            # Add basic net information.
+            set_connection_span_attrs(None, cnx_span, kwargs)
 
-        # Connection may fail at this point, in case it does, basic net info is already
-        # included so the user can check the net configuration she/he provided.
-        cnx = connect(*args, **kwargs)
+            # Connection may fail at this point, in case it does, basic net info is already
+            # included so the user can check the net configuration she/he provided.
+            cnx = connect(*args, **kwargs)
 
-        # connection went ok, let's refine the net information.
-        set_connection_span_attrs(cnx, cnx._span, kwargs)  # type: ignore[arg-type]
+            # connection went ok, let's refine the net information.
+            set_connection_span_attrs(cnx, cnx_span, kwargs)  # type: ignore[arg-type]
 
-        return TracedMySQLConnection(
-            wrapped=cnx,  # type: ignore[return-value, arg-type]
-        )
+            return TracedMySQLConnection(
+                wrapped=cnx,  # type: ignore[return-value, arg-type]
+            )
 
     return wrapper
 
@@ -427,7 +450,7 @@ def instrument(self, **kwargs: Any) -> None:
         if connector.connect != getattr(self, "_original_connect"):
             logger.warning("MySQL Connector/Python module already instrumented.")
             return
-        connector.connect = instrument_connect(
+        connector.connect = _instrument_connect(
             connect=getattr(self, "_original_connect"),
             tracer_provider=kwargs.get("tracer_provider"),
         )