defaults = {
    'openssh': {
        'allowed_users': {
            # Usernames for backup clients always start with 'c-'
            'c-*',
        },
    },
}

@metadata_reactor.provides(
    'backup-server/clients',
)
def get_my_clients(metadata):
    my_clients = {}

    for rnode in repo.nodes:
        if rnode.metadata.get('backups/exclude_from_backups', False) or rnode.dummy:
            continue

        my_clients[rnode.name] = {
            'user': rnode.metadata.get('backup-client/user-name'),
        }

    return {
        'backup-server': {
            'clients': my_clients,
        },
    }


@metadata_reactor.provides(
    'zfs/datasets',
    'zfs/snapshots/retain_per_dataset',
)
def zfs(metadata):
    zfs_datasets = {}
    zfs_retains = {}
    retain_defaults = {
        'weekly': 4,
        'monthly': 6,
    }

    for client in metadata.get('backup-server/clients', {}).keys():
        dataset = '{}/{}'.format(metadata.get('backup-server/zfs-base'), client)

        zfs_datasets[dataset] = {
            'mountpoint': '/srv/backups/{}'.format(client),
        }

        zfs_retains[dataset] = retain_defaults.copy()

    return {
        'zfs': {
            'datasets': zfs_datasets,
            'snapshots': {
                'retain_per_dataset': zfs_retains,
            },
        },
    }