mysql_user, mysql_role: add argument subtract_privs to revoke privileges explicitly (#333)

* add option subtract_privs to mysql_role and mysql_user

see https://github.com/ansible-collections/community.mysql/issues/331

* add integration tests for subtract_privs for mysql_role and mysql_user

* add changelog fragment for PR #333

* mysql_role, mysql_user: when subtract_privileges, don't grant unwanted privileges and don't revoke USAGE implicitly

* fix integration tests

* mysql_role, mysql_user: invalid privileges are ignored when subtract_privs is true -> document that and fix integration tests

* fix mysql_role integration tests

* fix mysql_role, mysql_user integration tests

* formatting

make the PEP8 check happy

* mysql_user and mysql_role: fix granting privileges when only the GRANT OPTION needs to be added

* mysql_user and mysql_role: log some updated privileges; explain integration test blind spot

* mysql_user and mysql_role: don't grant too much privileges

If only the grant option needs to be granted, at least one privilege needs to be granted to get valid syntax. USAGE is better for that than the existing privileges, because unwanted privileges would be re-added after revokation.

* mysql_user and mysql_role: fix type error

* Update changelogs/fragments/333-mysql_user-mysql_role-add-subtract_privileges-argument.yml

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

* Update plugins/modules/mysql_role.py

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

* Update plugins/modules/mysql_user.py

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

Co-authored-by: Felix Hamme <felix.hamme@ionos.com>
Co-authored-by: Andrew Klychkov <aaklychkov@mail.ru>

changelogs/fragments/333-mysql_user-mysql_role-add-subtract_privileges-argument.yml

@@ -0,0 +1,2 @@
+minor_changes:
+  - "mysql_user and mysql_role: Add the argument ``subtract_privs`` (boolean, default false, mutually exclusive with ``append_privs``). If set, the privileges given in ``priv`` are revoked and existing privileges are kept (https://github.com/ansible-collections/community.mysql/pull/333)."

plugins/module_utils/user.py

@@ -169,7 +169,7 @@ def is_hash(password):
 
 def user_mod(cursor, user, host, host_all, password, encrypted,
              plugin, plugin_hash_string, plugin_auth_string, new_priv,
-             append_privs, tls_requires, module, role=False, maria_role=False):
+             append_privs, subtract_privs, tls_requires, module, role=False, maria_role=False):
     changed = False
     msg = "User unchanged"
     grant_option = False
@@ -288,47 +288,61 @@ def user_mod(cursor, user, host, host_all, password, encrypted,
 
             # If the user has privileges on a db.table that doesn't appear at all in
             # the new specification, then revoke all privileges on it.
-            for db_table, priv in iteritems(curr_priv):
-                # If the user has the GRANT OPTION on a db.table, revoke it first.
-                if "GRANT" in priv:
-                    grant_option = True
-                if db_table not in new_priv:
-                    if user != "root" and "PROXY" not in priv and not append_privs:
-                        msg = "Privileges updated"
-                        if module.check_mode:
-                            return (True, msg)
-                        privileges_revoke(cursor, user, host, db_table, priv, grant_option, maria_role)
-                        changed = True
+            if not append_privs and not subtract_privs:
+                for db_table, priv in iteritems(curr_priv):
+                    # If the user has the GRANT OPTION on a db.table, revoke it first.
+                    if "GRANT" in priv:
+                        grant_option = True
+                    if db_table not in new_priv:
+                        if user != "root" and "PROXY" not in priv:
+                            msg = "Privileges updated"
+                            if module.check_mode:
+                                return (True, msg)
+                            privileges_revoke(cursor, user, host, db_table, priv, grant_option, maria_role)
+                            changed = True
 
             # If the user doesn't currently have any privileges on a db.table, then
             # we can perform a straight grant operation.
-            for db_table, priv in iteritems(new_priv):
-                if db_table not in curr_priv:
-                    msg = "New privileges granted"
-                    if module.check_mode:
-                        return (True, msg)
-                    privileges_grant(cursor, user, host, db_table, priv, tls_requires, maria_role)
-                    changed = True
+            if not subtract_privs:
+                for db_table, priv in iteritems(new_priv):
+                    if db_table not in curr_priv:
+                        msg = "New privileges granted"
+                        if module.check_mode:
+                            return (True, msg)
+                        privileges_grant(cursor, user, host, db_table, priv, tls_requires, maria_role)
+                        changed = True
 
             # If the db.table specification exists in both the user's current privileges
             # and in the new privileges, then we need to see if there's a difference.
             db_table_intersect = set(new_priv.keys()) & set(curr_priv.keys())
             for db_table in db_table_intersect:
 
-                # If appending privileges, only the set difference between new privileges and current privileges matter.
-                # The symmetric difference isn't relevant for append because existing privileges will not be revoked.
+                grant_privs = []
+                revoke_privs = []
                 if append_privs:
-                    priv_diff = set(new_priv[db_table]) - set(curr_priv[db_table])
+                    # When appending privileges, only missing privileges need to be granted. Nothing is revoked.
+                    grant_privs = list(set(new_priv[db_table]) - set(curr_priv[db_table]))
+                elif subtract_privs:
+                    # When subtracting privileges, revoke only the intersection of requested and current privileges.
+                    # No privileges are granted.
+                    revoke_privs = list(set(new_priv[db_table]) & set(curr_priv[db_table]))
                 else:
-                    priv_diff = set(new_priv[db_table]) ^ set(curr_priv[db_table])
+                    # When replacing (neither append_privs nor subtract_privs), grant all missing privileges
+                    # and revoke existing privileges that were not requested.
+                    grant_privs = list(set(new_priv[db_table]) - set(curr_priv[db_table]))
+                    revoke_privs = list(set(curr_priv[db_table]) - set(new_priv[db_table]))
+                if grant_privs == ['GRANT']:
+                    # USAGE grants no privileges, it is only needed because 'WITH GRANT OPTION' cannot stand alone
+                    grant_privs.append('USAGE')
 
-                if len(priv_diff) > 0:
-                    msg = "Privileges updated"
+                if len(grant_privs) + len(revoke_privs) > 0:
+                    msg = "Privileges updated: granted %s, revoked %s" % (grant_privs, revoke_privs)
                     if module.check_mode:
                         return (True, msg)
-                    if not append_privs:
-                        privileges_revoke(cursor, user, host, db_table, curr_priv[db_table], grant_option, maria_role)
-                    privileges_grant(cursor, user, host, db_table, new_priv[db_table], tls_requires, maria_role)
+                    if len(revoke_privs) > 0:
+                        privileges_revoke(cursor, user, host, db_table, revoke_privs, grant_option, maria_role)
+                    if len(grant_privs) > 0:
+                        privileges_grant(cursor, user, host, db_table, grant_privs, tls_requires, maria_role)
                     changed = True
 
         if role:
@@ -549,7 +563,7 @@ def sort_column_order(statement):
     return '%s(%s)' % (priv_name, ', '.join(columns))
 
 
-def privileges_unpack(priv, mode):
+def privileges_unpack(priv, mode, ensure_usage=True):
     """ Take a privileges string, typically passed as a parameter, and unserialize
     it into a dictionary, the same format as privileges_get() above. We have this
     custom format to avoid using YAML/JSON strings inside YAML playbooks. Example
@@ -595,7 +609,7 @@ def privileges_unpack(priv, mode):
         # Handle cases when there's privs like GRANT SELECT (colA, ...) in privs.
         output[pieces[0]] = normalize_col_grants(output[pieces[0]])
 
-    if '*.*' not in output:
+    if ensure_usage and '*.*' not in output:
         output['*.*'] = ['USAGE']
 
     return output

plugins/modules/mysql_role.py

@@ -51,7 +51,16 @@ options:
   append_privs:
     description:
       - Append the privileges defined by the I(priv) option to the existing ones
-        for this role instead of overwriting them.
+        for this role instead of overwriting them. Mutually exclusive with I(subtract_privs).
+    type: bool
+    default: no
+
+  subtract_privs:
+    description:
+      - Revoke the privileges defined by the I(priv) option and keep other existing privileges.
+        If set, invalid privileges in I(priv) are ignored.
+        Mutually exclusive with I(append_privs).
+    version_added: '3.2.0'
     type: bool
     default: no
 
@@ -233,6 +242,14 @@ EXAMPLES = r'''
     name: business
     members:
     - marketing
+
+- name: Ensure the role foo does not have the DELETE privilege
+  community.mysql.mysql_role:
+    state: present
+    name: foo
+    subtract_privs: yes
+    priv:
+      'db1.*': DELETE
 '''
 
 RETURN = '''#'''
@@ -821,9 +838,9 @@ class Role():
         return True
 
     def update(self, users, privs, check_mode=False,
-               append_privs=False, append_members=False,
-               detach_members=False, admin=False,
-               set_default_role_all=True):
+               append_privs=False, subtract_privs=False,
+               append_members=False, detach_members=False,
+               admin=False, set_default_role_all=True):
         """Update a role.
 
         Update a role if needed.
@@ -837,6 +854,8 @@ class Role():
             check_mode (bool): If True, just checks and does nothing.
             append_privs (bool): If True, adds new privileges passed through privs
                 not touching current privileges.
+            subtract_privs (bool): If True, revoke the privileges passed through privs
+                not touching other existing privileges.
             append_members (bool): If True, adds new members passed through users
                 not touching current members.
             detach_members (bool): If True, removes members passed through users from a role.
@@ -861,7 +880,7 @@ class Role():
         if privs:
             changed, msg = user_mod(self.cursor, self.name, self.host,
                                     None, None, None, None, None, None,
-                                    privs, append_privs, None,
+                                    privs, append_privs, subtract_privs, None,
                                     self.module, role=True, maria_role=self.is_mariadb)
 
         if admin:
@@ -931,6 +950,7 @@ def main():
         admin=dict(type='str'),
         priv=dict(type='raw'),
         append_privs=dict(type='bool', default=False),
+        subtract_privs=dict(type='bool', default=False),
         members=dict(type='list', elements='str'),
         append_members=dict(type='bool', default=False),
         detach_members=dict(type='bool', default=False),
@@ -945,6 +965,7 @@ def main():
             ('admin', 'members'),
             ('admin', 'append_members'),
             ('admin', 'detach_members'),
+            ('append_privs', 'subtract_privs'),
         ),
     )
 
@@ -958,6 +979,7 @@ def main():
     connect_timeout = module.params['connect_timeout']
     config_file = module.params['config_file']
     append_privs = module.params['append_privs']
+    subtract_privs = module.boolean(module.params['subtract_privs'])
     members = module.params['members']
     append_members = module.params['append_members']
     detach_members = module.params['detach_members']
@@ -1014,7 +1036,7 @@ def main():
             module.fail_json(msg=to_native(e))
 
         try:
-            priv = privileges_unpack(priv, mode)
+            priv = privileges_unpack(priv, mode, ensure_usage=not subtract_privs)
         except Exception as e:
             module.fail_json(msg='Invalid privileges string: %s' % to_native(e))
 
@@ -1043,11 +1065,13 @@ def main():
     try:
         if state == 'present':
             if not role.exists:
+                if subtract_privs:
+                    priv = None  # avoid granting unwanted privileges
                 changed = role.add(members, priv, module.check_mode, admin,
                                    set_default_role_all)
 
             else:
-                changed = role.update(members, priv, module.check_mode, append_privs,
+                changed = role.update(members, priv, module.check_mode, append_privs, subtract_privs,
                                       append_members, detach_members, admin,
                                       set_default_role_all)
 

plugins/modules/mysql_user.py

@@ -63,7 +63,15 @@ options:
   append_privs:
     description:
       - Append the privileges defined by priv to the existing ones for this
-        user instead of overwriting existing ones.
+        user instead of overwriting existing ones. Mutually exclusive with I(subtract_privs).
+    type: bool
+    default: no
+  subtract_privs:
+    description:
+      - Revoke the privileges defined by the I(priv) option and keep other existing privileges.
+        If set, invalid privileges in I(priv) are ignored.
+        Mutually exclusive with I(append_privs).
+    version_added: '3.2.0'
     type: bool
     default: no
   tls_requires:
@@ -306,6 +314,13 @@ EXAMPLES = r'''
       MAX_QUERIES_PER_HOUR: 10
       MAX_CONNECTIONS_PER_HOUR: 5
 
+- name: Ensure bob does not have the DELETE privilege
+  community.mysql.mysql_user:
+    name: bob
+    subtract_privs: yes
+    priv:
+      'db1.*': DELETE
+
 # Example .my.cnf file for setting the root password
 # [client]
 # user=root
@@ -352,6 +367,7 @@ def main():
         priv=dict(type='raw'),
         tls_requires=dict(type='dict'),
         append_privs=dict(type='bool', default=False),
+        subtract_privs=dict(type='bool', default=False),
         check_implicit_admin=dict(type='bool', default=False),
         update_password=dict(type='str', default='always', choices=['always', 'on_create'], no_log=False),
         sql_log_bin=dict(type='bool', default=True),
@@ -364,6 +380,7 @@ def main():
     module = AnsibleModule(
         argument_spec=argument_spec,
         supports_check_mode=True,
+        mutually_exclusive=(('append_privs', 'subtract_privs'),)
     )
     login_user = module.params["login_user"]
     login_password = module.params["login_password"]
@@ -379,6 +396,7 @@ def main():
     connect_timeout = module.params["connect_timeout"]
     config_file = module.params["config_file"]
     append_privs = module.boolean(module.params["append_privs"])
+    subtract_privs = module.boolean(module.params['subtract_privs'])
     update_password = module.params['update_password']
     ssl_cert = module.params["client_cert"]
     ssl_key = module.params["client_key"]
@@ -427,7 +445,7 @@ def main():
             mode = get_mode(cursor)
         except Exception as e:
             module.fail_json(msg=to_native(e))
-        priv = privileges_unpack(priv, mode)
+        priv = privileges_unpack(priv, mode, ensure_usage=not subtract_privs)
 
     if state == "present":
         if user_exists(cursor, user, host, host_all):
@@ -435,11 +453,11 @@ def main():
                 if update_password == "always":
                     changed, msg = user_mod(cursor, user, host, host_all, password, encrypted,
                                             plugin, plugin_hash_string, plugin_auth_string,
-                                            priv, append_privs, tls_requires, module)
+                                            priv, append_privs, subtract_privs, tls_requires, module)
                 else:
                     changed, msg = user_mod(cursor, user, host, host_all, None, encrypted,
                                             plugin, plugin_hash_string, plugin_auth_string,
-                                            priv, append_privs, tls_requires, module)
+                                            priv, append_privs, subtract_privs, tls_requires, module)
 
             except (SQLParseError, InvalidPrivsError, mysql_driver.Error) as e:
                 module.fail_json(msg=to_native(e))
@@ -447,6 +465,8 @@ def main():
             if host_all:
                 module.fail_json(msg="host_all parameter cannot be used when adding a user")
             try:
+                if subtract_privs:
+                    priv = None  # avoid granting unwanted privileges
                 changed = user_add(cursor, user, host, host_all, password, encrypted,
                                    plugin, plugin_hash_string, plugin_auth_string,
                                    priv, tls_requires, module.check_mode)

tests/integration/targets/test_mysql_role/defaults/main.yml

@@ -14,3 +14,4 @@ nonexistent: user3
 
 role0: role0
 role1: role1
+role2: role2

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

@@ -3,5 +3,15 @@
 # and should not be used as examples of how to write Ansible roles #
 ####################################################################
 
+- name: alias mysql command to include default options
+  set_fact:
+    mysql_command: "mysql -u{{ mysql_user }} -p{{ mysql_password }} -P{{ mysql_primary_port }} --protocol=tcp"
+
+
 # mysql_role module initial CI tests
 - import_tasks: mysql_role_initial.yml
+
+# Test that subtract_privs will only revoke the grants given by priv
+# (https://github.com/ansible-collections/community.mysql/issues/331)
+- include: test_priv_subtract.yml enable_check_mode=no
+- include: test_priv_subtract.yml enable_check_mode=yes

tests/integration/targets/test_mysql_role/tasks/test_priv_subtract.yml

@@ -0,0 +1,168 @@
+# Test code to ensure that subtracting privileges will not result in unnecessary changes.
+- vars:
+    mysql_parameters: &mysql_params
+      login_user: '{{ mysql_user }}'
+      login_password: '{{ mysql_password }}'
+      login_host: 127.0.0.1
+      login_port: '{{ mysql_primary_port }}'
+
+  block:
+
+    - name: Create test databases
+      mysql_db:
+        <<: *mysql_params
+        name: '{{ item }}'
+        state: present
+      loop:
+        - data1
+
+    - name: Create a role with an initial set of privileges
+      mysql_role:
+        <<: *mysql_params
+        name: '{{ role2 }}'
+        priv: 'data1.*:SELECT,INSERT'
+        state: present
+
+    - name: Run command to show privileges for role (expect privileges in stdout)
+      command: "{{ mysql_command }} -e \"SHOW GRANTS FOR '{{ role2 }}'\""
+      register: result
+
+    - name: Assert that the initial set of privileges matches what is expected
+      assert:
+        that:
+          - "'GRANT SELECT, INSERT ON `data1`.*' in result.stdout"
+
+    - name: Subtract privileges that are not in the current privileges, which should be a no-op
+      mysql_role:
+        <<: *mysql_params
+        name: '{{ role2 }}'
+        priv: 'data1.*:DELETE'
+        subtract_privs: yes
+        state: present
+      check_mode: '{{ enable_check_mode }}'
+      register: result
+
+    - name: Assert that there wasn't a change in permissions
+      assert:
+        that:
+          - "result.changed == false"
+
+    - name: Run command to show privileges for role (expect privileges in stdout)
+      command: "{{ mysql_command }} -e \"SHOW GRANTS FOR '{{ role2 }}'\""
+      register: result
+
+    - name: Assert that the permissions still match what was originally granted
+      assert:
+        that:
+          - "'GRANT SELECT, INSERT ON `data1`.*' in result.stdout"
+
+    - name: Subtract existing and not-existing privileges, but not all
+      mysql_role:
+        <<: *mysql_params
+        name: '{{ role2 }}'
+        priv: 'data1.*:INSERT,DELETE'
+        subtract_privs: yes
+        state: present
+      check_mode: '{{ enable_check_mode }}'
+      register: result
+
+    - name: Assert that there was a change because permissions were/would be revoked on data1.*
+      assert:
+        that:
+          - "result.changed == true"
+
+    - name: Run command to show privileges for role (expect privileges in stdout)
+      command: "{{ mysql_command }} -e \"SHOW GRANTS FOR '{{ role2 }}'\""
+      register: result
+
+    - name: Assert that the permissions were not changed if check_mode is set to 'yes'
+      assert:
+        that:
+          - "'GRANT SELECT, INSERT ON `data1`.*' in result.stdout"
+      when: enable_check_mode == 'yes'
+
+    - name: Assert that only DELETE was revoked if check_mode is set to 'no'
+      assert:
+        that:
+          - "'GRANT SELECT ON `data1`.*' in result.stdout"
+      when: enable_check_mode == 'no'
+
+    - name: Try to subtract invalid privileges
+      mysql_role:
+        <<: *mysql_params
+        name: '{{ role2 }}'
+        priv: 'data1.*:INVALID'
+        subtract_privs: yes
+        state: present
+      check_mode: '{{ enable_check_mode }}'
+      register: result
+
+    - name: Assert that there was no change because invalid permissions are ignored
+      assert:
+        that:
+          - "result.changed == false"
+
+    - name: Run command to show privileges for role (expect privileges in stdout)
+      command: "{{ mysql_command }} -e \"SHOW GRANTS FOR '{{ role2 }}'\""
+      register: result
+
+    - name: Assert that the permissions were not changed with check_mode=='yes'
+      assert:
+        that:
+          - "'GRANT SELECT, INSERT ON `data1`.*' in result.stdout"
+      when: enable_check_mode == 'yes'
+
+    - name: Assert that the permissions were not changed with check_mode=='no'
+      assert:
+        that:
+          - "'GRANT SELECT ON `data1`.*' in result.stdout"
+      when: enable_check_mode == 'no'
+
+    - name: trigger failure by trying to subtract and append privileges at the same time
+      mysql_role:
+        <<: *mysql_params
+        name: '{{ role2 }}'
+        priv: 'data1.*:SELECT'
+        subtract_privs: yes
+        append_privs: yes
+        state: present
+      check_mode: '{{ enable_check_mode }}'
+      register: result
+      ignore_errors: true
+
+    - name: Assert the previous execution failed
+      assert:
+        that:
+          - result is failed
+
+    - name: Run command to show privileges for role (expect privileges in stdout)
+      command: "{{ mysql_command }} -e \"SHOW GRANTS FOR '{{ role2 }}'\""
+      register: result
+
+    - name: Assert that the permissions stayed the same, with check_mode=='yes'
+      assert:
+        that:
+          - "'GRANT SELECT, INSERT ON `data1`.*' in result.stdout"
+      when: enable_check_mode == 'yes'
+
+    - name: Assert that the permissions stayed the same, with check_mode=='no'
+      assert:
+        that:
+          - "'GRANT SELECT ON `data1`.*' in result.stdout"
+      when: enable_check_mode == 'no'
+
+    ##########
+    # Clean up
+    - name: Drop test databases
+      mysql_db:
+        <<: *mysql_params
+        name: '{{ item }}'
+        state: present
+      loop:
+        - data1
+
+    - name: Drop test role
+      mysql_role:
+        <<: *mysql_params
+        name: '{{ role2 }}'
+        state: absent

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

@@ -274,6 +274,11 @@
     - include: test_priv_append.yml enable_check_mode=no
     - include: test_priv_append.yml enable_check_mode=yes
 
+    # Test that subtract_privs will only revoke the grants given by priv
+    # (https://github.com/ansible-collections/community.mysql/issues/331)
+    - include: test_priv_subtract.yml enable_check_mode=no
+    - include: test_priv_subtract.yml enable_check_mode=yes
+
     # Tests for the TLS requires dictionary
     - include: tls_requirements.yml
 

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

@@ -0,0 +1,173 @@
+# Test code to ensure that subtracting privileges will not result in unnecessary changes.
+- vars:
+    mysql_parameters: &mysql_params
+      login_user: '{{ mysql_user }}'
+      login_password: '{{ mysql_password }}'
+      login_host: 127.0.0.1
+      login_port: '{{ mysql_primary_port }}'
+
+  block:
+
+    - name: Create test databases
+      mysql_db:
+        <<: *mysql_params
+        name: '{{ item }}'
+        state: present
+      loop:
+      - data1
+
+    - name: Create a user with an initial set of privileges
+      mysql_user:
+        <<: *mysql_params
+        name: '{{ user_name_4 }}'
+        password: '{{ user_password_4 }}'
+        priv: 'data1.*:SELECT,INSERT'
+        state: present
+
+    - name: Run command to show privileges for user (expect privileges in stdout)
+      command: "{{ mysql_command }} -e \"SHOW GRANTS FOR '{{ user_name_4 }}'@'localhost'\""
+      register: result
+
+    - name: Assert that the initial set of privileges matches what is expected
+      assert:
+        that:
+          - "'GRANT SELECT, INSERT ON `data1`.*' in result.stdout"
+
+    - name: Subtract privileges that are not in the current privileges, which should be a no-op
+      mysql_user:
+        <<: *mysql_params
+        name: '{{ user_name_4 }}'
+        password: '{{ user_password_4 }}'
+        priv: 'data1.*:DELETE'
+        subtract_privs: yes
+        state: present
+      check_mode: '{{ enable_check_mode }}'
+      register: result
+
+    - name: Assert that there wasn't a change in permissions
+      assert:
+        that:
+          - "result.changed == false"
+
+    - name: Run command to show privileges for user (expect privileges in stdout)
+      command: "{{ mysql_command }} -e \"SHOW GRANTS FOR '{{ user_name_4 }}'@'localhost'\""
+      register: result
+
+    - name: Assert that the permissions still match what was originally granted
+      assert:
+        that:
+          - "'GRANT SELECT, INSERT ON `data1`.*' in result.stdout"
+
+    - name: Subtract existing and not-existing privileges, but not all
+      mysql_user:
+        <<: *mysql_params
+        name: '{{ user_name_4 }}'
+        password: '{{ user_password_4 }}'
+        priv: 'data1.*:INSERT,DELETE'
+        subtract_privs: yes
+        state: present
+      check_mode: '{{ enable_check_mode }}'
+      register: result
+
+    - name: Assert that there was a change because permissions were/would be revoked on data1.*
+      assert:
+        that:
+          - "result.changed == true"
+
+    - name: Run command to show privileges for user (expect privileges in stdout)
+      command: "{{ mysql_command }} -e \"SHOW GRANTS FOR '{{ user_name_4 }}'@'localhost'\""
+      register: result
+
+    - name: Assert that the permissions were not changed if check_mode is set to 'yes'
+      assert:
+        that:
+          - "'GRANT SELECT, INSERT ON `data1`.*' in result.stdout"
+      when: enable_check_mode == 'yes'
+
+    - name: Assert that only DELETE was revoked if check_mode is set to 'no'
+      assert:
+        that:
+          - "'GRANT SELECT ON `data1`.*' in result.stdout"
+      when: enable_check_mode == 'no'
+
+    - name: Try to subtract invalid privileges
+      mysql_user:
+        <<: *mysql_params
+        name: '{{ user_name_4 }}'
+        password: '{{ user_password_4 }}'
+        priv: 'data1.*:INVALID'
+        subtract_privs: yes
+        state: present
+      check_mode: '{{ enable_check_mode }}'
+      register: result
+
+    - name: Assert that there was no change because invalid permissions are ignored
+      assert:
+        that:
+          - "result.changed == false"
+
+    - name: Run command to show privileges for user (expect privileges in stdout)
+      command: "{{ mysql_command }} -e \"SHOW GRANTS FOR '{{ user_name_4 }}'@'localhost'\""
+      register: result
+
+    - name: Assert that the permissions were not changed with check_mode=='yes'
+      assert:
+        that:
+          - "'GRANT SELECT, INSERT ON `data1`.*' in result.stdout"
+      when: enable_check_mode == 'yes'
+
+    - name: Assert that the permissions were not changed with check_mode=='no'
+      assert:
+        that:
+          - "'GRANT SELECT ON `data1`.*' in result.stdout"
+      when: enable_check_mode == 'no'
+
+    - name: trigger failure by trying to subtract and append privileges at the same time
+      mysql_user:
+        <<: *mysql_params
+        name: '{{ user_name_4 }}'
+        password: '{{ user_password_4 }}'
+        priv: 'data1.*:SELECT'
+        subtract_privs: yes
+        append_privs: yes
+        state: present
+      check_mode: '{{ enable_check_mode }}'
+      register: result
+      ignore_errors: true
+
+    - name: Assert the previous execution failed
+      assert:
+        that:
+          - result is failed
+
+    - name: Run command to show privileges for user (expect privileges in stdout)
+      command: "{{ mysql_command }} -e \"SHOW GRANTS FOR '{{ user_name_4 }}'@'localhost'\""
+      register: result
+
+    - name: Assert that the permissions stayed the same, with check_mode=='yes'
+      assert:
+        that:
+          - "'GRANT SELECT, INSERT ON `data1`.*' in result.stdout"
+      when: enable_check_mode == 'yes'
+
+    - name: Assert that the permissions stayed the same, with check_mode=='no'
+      assert:
+        that:
+          - "'GRANT SELECT ON `data1`.*' in result.stdout"
+      when: enable_check_mode == 'no'
+
+    ##########
+    # Clean up
+    - name: Drop test databases
+      mysql_db:
+        <<: *mysql_params
+        name: '{{ item }}'
+        state: present
+      loop:
+      - data1
+
+    - name: Drop test user
+      mysql_user:
+        <<: *mysql_params
+        name: '{{ user_name_4 }}'
+        state: absent

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

@@ -173,7 +173,7 @@
         state: present
       register: result
 
-    # FIXME: on mariadb 10.5 there's always a change
+    # FIXME: on mariadb >=10.5.2 there's always a change because the REPLICATION CLIENT privilege was renamed to BINLOG MONITOR
     - name: Assert that priv did not change
       assert:
         that: