cffi-bindings.py

#!/usr/bin/env python3

# Copyright (C) 2023 Canonical, Ltd.
# Author: Lukas Märdian <slyon@ubuntu.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 3.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import io
import tempfile
from netplan import Parser, State, _create_yaml_patch
from netplan import NetplanException, NetplanParserException
FALLBACK_FILENAME = '70-netplan-set.yaml'

if __name__ == '__main__':
    yaml_path = ['network', 'ethernets', 'eth99', 'dhcp4']
    value = 'true'

    parser = Parser()
    with tempfile.TemporaryFile() as tmp:
        _create_yaml_patch(yaml_path, value, tmp)
        tmp.flush()

        # Parse the full, existing YAML config hierarchy
        parser.load_yaml_hierarchy(rootdir='/')

        # Load YAML patch, containing our new settings
        tmp.seek(0, io.SEEK_SET)
        parser.load_yaml(tmp)

        # Validate the final parser state
        state = State()
        try:
            # validation of current state + new settings
            state.import_parser_results(parser)
        except NetplanParserException as e:
            print('Error in', e.filename, 'Row/Col', e.line, e.column, '->', e.message)
        except NetplanException as e:
            print('Error:', e.message)

        # Walk through all NetdefIDs in the state and print their backend
        # renderer, to demonstrate working with NetDefinitionIterator &
        # NetDefinition
        for netdef_id, netdef in state.netdefs.items():
            print('Netdef', netdef_id, 'is managed by:', netdef.backend)

        # Write the new data from the YAML patch to disk, updating an
        # existing Netdef, if file already exists, or FALLBACK_FILENAME
        state._update_yaml_hierarchy(FALLBACK_FILENAME, rootdir='/')