Custom ansible dynamic inventory that allows a directory of variables to be shared across multiple inventories

shared.py

#!/usr/bin/env python

import os
import six
import argparse

from six.moves import configparser

from ansible.parsing.dataloader import DataLoader
from ansible.inventory import Inventory
from ansible.vars import VariableManager

try:
    import json
except ImportError:
    import simplejson as json


class SharedStaticInventory(object):

    def _empty_inventory(self):
        return {"_meta" : {"hostvars" : {}}}

    def __init__(self):
        ''' Main execution path '''
        self.inventory = self._empty_inventory()
        self.shared_dir = os.path.realpath('../shared')

        # Read settings
        self.read_settings()

        loader = DataLoader()
        variable_manager = VariableManager()
        self.shared_inventory = Inventory(loader=loader, variable_manager=variable_manager,
                              host_list=self.shared_dir)
        variable_manager.set_inventory(self.shared_inventory)
        group_vars_files = variable_manager._group_vars_files

        for group_name, group_vars in group_vars_files.iteritems():
            self.inventory[group_name] = {'vars' : group_vars[0]}

        data_to_print = self.json_format_dict(self.inventory, pretty=True)
        print(data_to_print)

    def read_settings(self):
        ''' Reads the settings from the shared.ini file '''
        scriptbasename = os.path.basename(__file__)
        scriptbasename = scriptbasename.replace('.py', '')

        defaults = {'shared': {
            'ini_path': os.path.join(os.path.dirname(__file__), '%s.ini' % scriptbasename)
            }
        }

        if six.PY3:
            config = configparser.ConfigParser()
        else:
            config = configparser.SafeConfigParser()
        ini_path = os.environ.get('SHARED_INI_PATH', defaults['shared']['ini_path'])
        ini_path = os.path.expanduser(os.path.expandvars(ini_path))
        ini_dir = os.path.realpath(os.path.dirname(ini_path))
        config.read(ini_path)

        # Get path of shared inventory
        if config.has_option('shared', 'path'):
            shared_dir = config.get('shared', 'path')
            if shared_dir[0] != '/':
                shared_dir = '{}/{}'.format(ini_dir, shared_dir)
            self.shared_dir = shared_dir

    def json_format_dict(self, data, pretty=False):
        ''' Converts a dict to a JSON object and dumps it as a formatted string '''
        if pretty:
            return json.dumps(data, sort_keys=True, indent=2)
        else:
            return json.dumps(data)


if __name__ == '__main__':
    # Run the script
    SharedStaticInventory()