Get the policies that should be applied to a token for minion_id

def _get_policies(minion_id, config):
    '''
    Get the policies that should be applied to a token for minion_id
    '''
    _, grains, _ = salt.utils.minions.get_minion_data(minion_id, __opts__)
    policy_patterns = config.get(
                                 'policies',
                                 ['saltstack/minion/{minion}', 'saltstack/minions']
                                )
    mappings = {'minion': minion_id, 'grains': grains or {}}

    policies = []
    for pattern in policy_patterns:
        try:
            for expanded_pattern in _expand_pattern_lists(pattern, **mappings):
                policies.append(
                                expanded_pattern.format(**mappings)
                                                .lower()  # Vault requirement
                               )
        except KeyError:
            log.warning('Could not resolve policy pattern %s', pattern)

    log.debug('%s policies: %s', minion_id, policies)
    return policies