support opentelemetry-instrumentation

Author: methane

src/MySQLdb/connections.py

@@ -204,12 +204,19 @@ class object, used to create cursors (keyword only)
             if type(k) is not int  # noqa: E721
         }
 
+        # support opentelemetry-instrumentation-dbapi
+        self.host = host
+        self.port = port
+        self.user = user
         self.database = kwargs2.get("database", "")
+        # otel-inst-mysqlclient uses db instead of database.
+        self.db = self.database
+        # NOTE: We have not supported semantic conventions yet.
+        # https://opentelemetry.io/docs/specs/semconv/database/sql/
 
         self._server_version = tuple(
             [numeric_part(n) for n in self.get_server_info().split(".")[:2]]
         )
-
         self.encoding = "ascii"  # overridden in set_character_set()
 
         if not charset: