[mysql] Log warning on 1045 error when SSL not configured (DataDog#23607)

* [mysql] Log warning on 1045 error when SSL not configured

When pymysql raises OperationalError(1045) and no ssl config is present,
log a warning suggesting SSL may be required by the MySQL instance.
This helps diagnose cases where CloudSQL or other managed MySQL services
enforce SSL and return 1045 instead of a clear SSL error.

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

* Rename changelog entry to match PR number 23607

* Fix log capture in 1045 SSL warning tests

CheckLoggingAdapter is a data descriptor — patch.object on the instance
is silently ignored. Capture warnings via check.log.logger handler instead.

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

* Remove test additions from PR — fix only

---------

Co-authored-by: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

Author: pierreln-dd

mysql/changelog.d/23607.fixed

@@ -0,0 +1 @@
+Log a warning when a 1045 access denied error occurs with no SSL configuration, hinting that SSL may be required by the MySQL instance.

mysql/datadog_checks/mysql/mysql.py

@@ -563,6 +563,18 @@ def _connect(self):
                 self.SERVICE_CHECK_NAME, AgentCheck.OK, tags=service_check_tags, hostname=self.reported_hostname
             )
             yield db
+        except pymysql.err.OperationalError as e:
+            self.service_check(
+                self.SERVICE_CHECK_NAME, AgentCheck.CRITICAL, tags=service_check_tags, hostname=self.reported_hostname
+            )
+            if e.args[0] == 1045 and not self._config.ssl:
+                self.log.warning(
+                    "Access denied error (1045) with no SSL configuration. If your MySQL instance requires SSL "
+                    "connections, configure the 'ssl' option in the check configuration "
+                    "(e.g. 'ssl.check_hostname: false' for connections without certificate verification). "
+                    "See https://docs.datadoghq.com/database_monitoring/setup_mysql/ for more details."
+                )
+            raise
         except Exception:
             self.service_check(
                 self.SERVICE_CHECK_NAME, AgentCheck.CRITICAL, tags=service_check_tags, hostname=self.reported_hostname