mysql_user: add session_vars argument (#489)

* mysql_user: add session_vars argument

* Update tests/integration/targets/test_mysql_user/tasks/main.yml

Co-authored-by: Alexei Znamensky <103110+russoz@users.noreply.github.com>

Co-authored-by: Alexei Znamensky <103110+russoz@users.noreply.github.com>

changelogs/fragments/0_mysql_user_session_vars.yml

@@ -0,0 +1,2 @@
+minor_changes:
+- mysql_user - add the ``session_vars`` argument to set session variables at the beginning of module execution (https://github.com/ansible-collections/community.mysql/issues/478).

plugins/module_utils/mysql.py

@@ -34,6 +34,8 @@ mysql_driver_fail_msg = ('A MySQL module is required: for Python 2.7 either PyMy
                          'Consider setting ansible_python_interpreter to use '
                          'the intended Python version.')
 
+from ansible_collections.community.mysql.plugins.module_utils.database import mysql_quote_identifier
+
 
 def parse_from_mysql_config_file(cnf):
     # Default values of comment_prefix is '#' and ';'.
@@ -149,3 +151,13 @@ def get_server_version(cursor):
         version_str = result[0]
 
     return version_str
+
+
+def set_session_vars(module, cursor, session_vars):
+    """Set session vars."""
+    for var, value in session_vars.items():
+        query = "SET SESSION %s = " % mysql_quote_identifier(var, 'vars')
+        try:
+            cursor.execute(query + "%s", (value,))
+        except Exception as e:
+            module.fail_json(msg='Failed to execute %s%s: %s' % (query, value, e))

plugins/modules/mysql_user.py

@@ -149,6 +149,12 @@ options:
       - Used when I(state=present), ignored otherwise.
     type: dict
     version_added: '0.1.0'
+  session_vars:
+    description:
+      - "Dictionary of session variables in form of C(variable: value) to set at the beginning of module execution."
+      - Cannot be used to set global variables, use the M(community.mysql.mysql_variables) module instead.
+    type: dict
+    version_added: '3.6.0'
 
 notes:
    - "MySQL server installs with default I(login_user) of C(root) and no password.
@@ -208,12 +214,15 @@ EXAMPLES = r'''
     priv: '*.*:ALL'
     state: present
 
+# Set session var wsrep_on=off before creating the user
 - name: Create database user with password and all database privileges and 'WITH GRANT OPTION'
   community.mysql.mysql_user:
     name: bob
     password: 12345
     priv: '*.*:ALL,GRANT'
     state: present
+    session_vars:
+      wsrep_on: off
 
 - name: Create user with password, all database privileges and 'WITH GRANT OPTION' in db1 and db2
   community.mysql.mysql_user:
@@ -341,7 +350,11 @@ RETURN = '''#'''
 from ansible.module_utils.basic import AnsibleModule
 from ansible_collections.community.mysql.plugins.module_utils.database import SQLParseError
 from ansible_collections.community.mysql.plugins.module_utils.mysql import (
-    mysql_connect, mysql_driver, mysql_driver_fail_msg, mysql_common_argument_spec
+    mysql_connect,
+    mysql_driver,
+    mysql_driver_fail_msg,
+    mysql_common_argument_spec,
+    set_session_vars,
 )
 from ansible_collections.community.mysql.plugins.module_utils.user import (
     convert_priv_dict_to_str,
@@ -385,6 +398,7 @@ def main():
         plugin_auth_string=dict(default=None, type='str'),
         resource_limits=dict(type='dict'),
         force_context=dict(type='bool', default=False),
+        session_vars=dict(type='dict'),
     )
     module = AnsibleModule(
         argument_spec=argument_spec,
@@ -419,6 +433,8 @@ def main():
     plugin_hash_string = module.params["plugin_hash_string"]
     plugin_auth_string = module.params["plugin_auth_string"]
     resource_limits = module.params["resource_limits"]
+    session_vars = module.params["session_vars"]
+
     if priv and not isinstance(priv, (str, dict)):
         module.fail_json(msg="priv parameter must be str or dict but %s was passed" % type(priv))
 
@@ -447,6 +463,9 @@ def main():
     if not sql_log_bin:
         cursor.execute("SET SQL_LOG_BIN=0;")
 
+    if session_vars:
+        set_session_vars(module, cursor, session_vars)
+
     get_impl(cursor)
 
     if priv is not None:

tests/integration/targets/test_mysql_user/tasks/main.yml

@@ -62,6 +62,8 @@
         name: '{{user_name_1}}'
         password: '{{user_password_1}}'
         state: present
+        session_vars:
+          sort_buffer_size: 1024
       register: result
 
     - name: assert output message mysql user was not created
@@ -69,6 +71,24 @@
         that:
           - result is not changed
 
+    # Try to set wrong session variable, must fail
+    - name: create mysql user trying to set global variable which is forbidden
+      mysql_user:
+        <<: *mysql_params
+        name: '{{user_name_1}}'
+        password: '{{user_password_1}}'
+        state: present
+        session_vars:
+          max_connections: 1000
+      register: result
+      ignore_errors: true 
+
+    - name: we cannot set a global variable
+      assert:
+        that:
+          - result is failed
+          - result.msg is search('is a GLOBAL variable')
+
     # ============================================================
     # remove mysql user and verify user is removed from mysql database
     #