mysql_info - Add connector_name and connector_version to returned value (#497)

* Add methods to retrieve connector name and version
* Document that mysqlclient is also named MySQLdb
* Document version_added
* Add connector name and version in the returned block
* Cut condition to display any name that is return

In case of MySQLdb is renamed in mysqlclient. In that case, the
integration tests will catch this the day we update the connector
version.

Co-authored-by: Andrew Klychkov <aaklychkov@mail.ru>
(cherry picked from commit a5f3296d73)

plugins/module_utils/mysql.py

@@ -23,6 +23,7 @@ try:
     _mysql_cursor_param = 'cursor'
 except ImportError:
     try:
+        # mysqlclient is called MySQLdb
         import MySQLdb as mysql_driver
         import MySQLdb.cursors
         _mysql_cursor_param = 'cursorclass'
@@ -35,6 +36,43 @@ mysql_driver_fail_msg = ('A MySQL module is required: for Python 2.7 either PyMy
                          'the intended Python version.')
 
 
+def get_connector_name(connector):
+    """ (class) -> str
+    Return the name of the connector (pymysql or mysqlclient (MySQLdb))
+    or 'Unknown' if not pymysql or MySQLdb. When adding a
+    connector here, also modify get_connector_version.
+    """
+    if connector is None or not hasattr(connector, '__name__'):
+        return 'Unknown'
+
+    return connector.__name__
+
+
+def get_connector_version(connector):
+    """ (class) -> str
+    Return the version of pymysql or mysqlclient (MySQLdb).
+    Return 'Unknown' if the connector name is unknown.
+    """
+
+    if connector is None:
+        return 'Unknown'
+
+    connector_name = get_connector_name(connector)
+
+    if connector_name == 'pymysql':
+        # pymysql has two methods:
+        # - __version__ that returns the string: 0.7.11.None
+        # - VERSION that returns the tuple (0, 7, 11, None)
+        v = connector.VERSION[:3]
+        return '.'.join(map(str, v))
+    elif connector_name == 'MySQLdb':
+        # version_info returns the tuple (2, 1, 1, 'final', 0)
+        v = connector.version_info[:3]
+        return '.'.join(map(str, v))
+    else:
+        return 'Unknown'
+
+
 def parse_from_mysql_config_file(cnf):
     # Default values of comment_prefix is '#' and ';'.
     # '!' added to prevent a parsing error