feat[mysql_info]: add 'users_info' filter (#580)

* add documentation for new mysql_info users_info filter

* Add integration tests for mysql_info users_info

* fix list parsing when cursor come from mysql_info

Mysql_info use a DictCursor and mysql_user a normal cursor.

* fix case when an account as same user but different host and password

* document why certain authentications plugins cause issues

* add version_added for users_info to the documentation

* Add 'users' description to differentiate it from 'users_info'

---------

Co-authored-by: Andrew Klychkov <aaklychkov@mail.ru>

plugins/module_utils/user.py

@@ -112,23 +112,40 @@ def get_grants(cursor, user, host):
     return grants.split(", ")
 
 
-def get_existing_authentication(cursor, user):
+def get_existing_authentication(cursor, user, host):
     # Return the plugin and auth_string if there is exactly one distinct existing plugin and auth_string.
     cursor.execute("SELECT VERSION()")
-    if 'mariadb' in cursor.fetchone()[0].lower():
+    srv_type = cursor.fetchone()
+    # Mysql_info use a DictCursor so we must convert back to a list
+    # otherwise we get KeyError 0
+    if isinstance(srv_type, dict):
+        srv_type = list(srv_type.values())
+
+    if 'mariadb' in srv_type[0].lower():
         # before MariaDB 10.2.19 and 10.3.11, "password" and "authentication_string" can differ
         # when using mysql_native_password
         cursor.execute("""select plugin, auth from (
             select plugin, password as auth from mysql.user where user=%(user)s
+            and host=%(host)s
             union select plugin, authentication_string as auth from mysql.user where user=%(user)s
-            ) x group by plugin, auth limit 2
-        """, {'user': user})
+            and host=%(host)s) x group by plugin, auth limit 2
+        """, {'user': user, 'host': host})
     else:
-        cursor.execute("""select plugin, authentication_string as auth from mysql.user where user=%(user)s
-            group by plugin, authentication_string limit 2""", {'user': user})
+        cursor.execute("""select plugin, authentication_string as auth
+            from mysql.user where user=%(user)s and host=%(host)s
+            group by plugin, authentication_string limit 2""", {'user': user, 'host': host})
     rows = cursor.fetchall()
-    if len(rows) == 1:
-        return {'plugin': rows[0][0], 'auth_string': rows[0][1]}
+
+    # Mysql_info use a DictCursor so we must convert back to a list
+    # otherwise we get KeyError 0
+    if isinstance(rows, dict):
+        rows = list(rows.values())
+
+    if isinstance(rows[0], tuple):
+        return {'plugin': rows[0][0], 'plugin_auth_string': rows[0][1]}
+
+    if isinstance(rows[0], dict):
+        return {'plugin': rows[0].get('plugin'), 'plugin_auth_string': rows[0].get('auth')}
     return None
 
 
@@ -149,7 +166,7 @@ def user_add(cursor, user, host, host_all, password, encrypted,
 
     used_existing_password = False
     if reuse_existing_password:
-        existing_auth = get_existing_authentication(cursor, user)
+        existing_auth = get_existing_authentication(cursor, user, host)
         if existing_auth:
             plugin = existing_auth['plugin']
             plugin_hash_string = existing_auth['auth_string']
@@ -478,6 +495,12 @@ def privileges_get(cursor, user, host, maria_role=False):
             return x
 
     for grant in grants:
+
+        # Mysql_info use a DictCursor so we must convert back to a list
+        # otherwise we get KeyError 0
+        if isinstance(grant, dict):
+            grant = list(grant.values())
+
         if not maria_role:
             res = re.match("""GRANT (.+) ON (.+) TO (['`"]).*\\3@(['`"]).*\\4( IDENTIFIED BY PASSWORD (['`"]).+\\6)? ?(.*)""", grant[0])
         else:
@@ -777,6 +800,11 @@ def get_resource_limits(cursor, user, host):
     cursor.execute(query, (user, host))
     res = cursor.fetchone()
 
+    # Mysql_info use a DictCursor so we must convert back to a list
+    # otherwise we get KeyError 0
+    if isinstance(res, dict):
+        res = list(res.values())
+
     if not res:
         return None
 
@@ -788,11 +816,22 @@ def get_resource_limits(cursor, user, host):
     }
 
     cursor.execute("SELECT VERSION()")
-    if 'mariadb' in cursor.fetchone()[0].lower():
+    srv_type = cursor.fetchone()
+    # Mysql_info use a DictCursor so we must convert back to a list
+    # otherwise we get KeyError 0
+    if isinstance(srv_type, dict):
+        srv_type = list(srv_type.values())
+
+    if 'mariadb' in srv_type[0].lower():
         query = ('SELECT max_statement_time AS MAX_STATEMENT_TIME '
                  'FROM mysql.user WHERE User = %s AND Host = %s')
         cursor.execute(query, (user, host))
         res_max_statement_time = cursor.fetchone()
+
+        # Mysql_info use a DictCursor so we must convert back to a list
+        # otherwise we get KeyError 0
+        if isinstance(res_max_statement_time, dict):
+            res_max_statement_time = list(res_max_statement_time.values())
         current_limits['MAX_STATEMENT_TIME'] = res_max_statement_time[0]
 
     return current_limits