State of states module for salt (saltstack)

states.state.py

"""
State module
============

The state module for logical union of several states.


Available Functions
------------------- 

The module only has a single function, the ``present`` function

present

       Combining multiple states in one
       
       example:
       
       .. code-block:: yaml
       
            # some service configs in one state
            some_config:
                state:
                    - present
                    - tag: v1.0 # you can mark state by tag, but not require
                    - watch: # or require declaration
                        - file: /etc/some_service/conf_1.conf
                        - file: /etc/some_service/conf_2.conf
                        - file: /etc/some_service/conf_3.conf
        
            some_service:
                service:
                    - running
                    # if will changed some of some_config watchers OR tag
                    # service will be restarted
                    - watch:
                        - state: some_config
                        
            another_service:
                service:
                    - running
                    # Service check running if all watch (or require) state in
                    # some_config and state file: /etc/another_service/conf.conf
                    # is true
                    - require:
                        - state: some_config
                        - file: /etc/another_service/conf.conf

            # union two state service as one state
            services_running:
                state:
                    - present
                    - require:
                        - service: some_service
                        - service: another_service
                        
            do_some_think:
                cmd:
                    - wait
                    - watch:
                        - state: services_running
"""


def present(name, tag=None):
    """
    State

    :param name: state name
    :param tag: tag
    """

    if tag:
        data = __salt__['data.load']()
        key = 'state/%s/tag' % name
        val = data.get(key, None)

        if not val:
            __salt__['data.update'](key, tag)
            return {'name': name,
                    'result': True,
                    'changes': {'new': 'State tagged as %s' % tag},
                    'comment': 'State present'}

        if val != tag:
            __salt__['data.update'](key, tag)
            return {'name': name,
                    'result': True,
                    'changes': {'diff': 'State updated tag %s -> %s'
                                % (val, tag)},
                    'comment': 'State present'}

    return {'name': name,
            'result': True,
            'changes': {},
            'comment': 'State present'}

#  ----------------------------------------------------------------------------


def watcher(name, tag=None):

    res = present(name, tag)
    res['changes'].update({'state': 'Watch requires changed'})

    return res