def get_network(properties):
    """ Get the configuration that connects the instance to an existing network
        and assigns to it an ephemeral public IP.
    """

    network_name = properties.get('network')
    return {
        'network': 'global/networks/{}'.format(network_name),
        'accessConfigs': [
            {
                'name': 'External NAT',
                'type': 'ONE_TO_ONE_NAT'
            }
        ]
    }