Juno -> Kilo inventory migrator

inventory_migrate.py

#!/usr/bin/env python

import json
from pprint import pprint
import sys


def get_bridges(inventory):
    "Returns bridge names and interface information for provider networks."

    all_vars = inventory['all']['vars']
    provider_networks = all_vars['provider_networks']
    bridges = {}
    for net_name in ('storage', 'tunnel', 'container'):
        bridges[net_name] = {}
        for pn in provider_networks:
            network = pn['network']
            if 'ip_from_q' not in network.keys():
                continue
            if network['ip_from_q'] == net_name:
                bridges[net_name]['name'] = network['container_bridge']
                bridges[net_name]['iface'] = network['container_interface']
    return bridges


def update_container_vars(inventory, bridges):
    """
    Maps container network information to the new kilo structure.

    Kilo introduced a 'container_networks' dict per host that looks like
    this:

        "container_networks": {
            "container_address": {
                "address": <ip>,
                "bridge": <bridge name>,
                "interface": <interface name>,
                "netmask": <netmask>
            },
            "storage_address":{
                <same keypairs above>
            }
        }

    In Juno, this was all contained in variables at the host level.
    """
    hostvars = inventory['_meta']['hostvars']

    for hostname, host in hostvars.items():
        if 'container_networks' in host.keys():
            continue

        networks = {}
        for net_type in ('container', 'storage', 'tunnel'):
            if ('%s_address' % net_type) not in host.keys():
                continue

            net_addr = {
                'address': host.get('%s_address' % net_type),
                'netmask': host.get('%s_netmask' % net_type),
                'bridge': bridges.get('%s' % net_type)['name'],
                'interface': bridges.get('%s' % net_type)['iface'],
            }
            networks['%s_address' % net_type] = net_addr

        host['container_networks'] = networks

        scrub_old_keys(host)


def scrub_old_keys(host):
    "Removes key/value pairs that are not present in kilo."

    # Being explicit here, since 'container_address'
    # remains a top-level item in the dictionary
    old_keys = [
        'container_network',
        'container_netmask',
        'storage_address',
        'storage_netmask',
        'tunnel_address',
        'tunnel_netmask',
    ]

    for key in old_keys:
        if key in host.keys():
            del host[key]

if __name__ == "__main__":
    with open('rpc_inventory.json', 'r') as fp:
        inventory = json.load(fp)

    bridges = get_bridges(inventory)
    update_container_vars(inventory, bridges)
    with open('temp.json', 'w') as fp:
        json.dump(inventory, indent=4, sort_keys=True)