assert_group

#!/usr/bin/python
# -*- coding: utf-8 -*-

# (c) 2014, Allan Denot <adenot@gmail.com>
#
# This file is part of Ansible
#
# Ansible is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.

import grp

DOCUMENTATION = '''
---
module: assert_group
version_added: 1.5
short_description: Assert file and directory group owner
description:
  - Check group of a given file or directory
options: 
  name: 
    description:
    - path to the file or directory to check its permissions
    required: True
    default: null
  should_be: 
    description: 
    - expected group of the file/directory
    required: False
    default: null
author: Allan Denot
'''

EXAMPLES = '''
# Assert if testfile is owned by the group users
assert_group: name=/tmp/testfile should_be=users
'''

def file_group(filename):
    filename = os.path.expanduser(filename)
    st = os.lstat(filename)
    group = grp.getgrgid(st.st_gid).gr_name

    return group

def main():
    module = AnsibleModule(
        argument_spec = dict(
            name=dict(required=True, default=None),
            should_be=dict(required=True),
        ),
        supports_check_mode=True
    )
    group = module.params.get('should_be')
    path = os.path.expanduser(module.params['name'])

    if not os.path.lexists(path):
        module.fail_json(msg="%s does not exist" % path)

    actual_group = file_group(path)

    if group and actual_group != group:
        module.fail_json(msg="%s owned by group %s, should be owned by group %s" % (path, actual_group, group))
    
    module.exit_json()
    
# this is magic, see lib/ansible/module_common.py
#<<INCLUDE_ANSIBLE_MODULE_COMMON>>
main()