de/heat-templates/scripts/prepare-metadata.py

#!/usr/bin/python3
#
# Copyright 2018 Mirantis, Inc.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.


"""Prepare metadata python module

The module is aimed to prepare system files files (networking configs etc)
based on lab metadata.

Example:
  python prepare-metadata --metadata-file '/etc/lab-metadata.yaml'

Example of lab-metadata.yaml

'52:54:00:10:94:78':
  write_files:
  - path: '/tmp/123.yaml'
    content: |
      foo: bar

Attributes:
  metadata-file - The file with metadata
"""


__version__ = '1.0'

import argparse
import os
import yaml
import logging
import netifaces
import sys

LOG = logging.getLogger(__name__)


def main():
    logging.basicConfig(
        format='%(asctime)s - %(levelname)s - %(message)s'
    )
    LOG.setLevel(logging.INFO)

    parser = argparse.ArgumentParser(
        description=('Render system files based on metadata')
    )

    group = parser.add_argument_group()
    group.add_argument(
        '--metadata-file',
        help='The path to metadata file.',
        required=True
    )
    args = parser.parse_args()

    with open(args.metadata_file) as f:
        metadata = yaml.safe_load(f)
    node_meta = get_node_metadata(metadata)
    if node_meta is not None:
        LOG.info(f"Processing node_metadata: {node_meta}")
        create_files(node_meta.get('write_files', []))
    else:
        LOG.error("No matches to MACs for node_metadata found")

def get_interface_mac(iface_name):
    mac = None
    ifaddresses = netifaces.ifaddresses(iface_name)
    link = ifaddresses.get(netifaces.AF_LINK, [])
    if link:
        return link[0]['addr']

def get_node_macs():
    ifaces = netifaces.interfaces()
    macs = [get_interface_mac(iface_name) for iface_name in ifaces]
    return [mac for mac in macs if mac is not None]

def get_node_metadata(metadata):
    for mac in get_node_macs():
        if mac in metadata:
             return metadata[mac]

def create_files(files_meta):
    for file_meta in files_meta:
        path = file_meta['path']
        content = file_meta['content']
        permissions = int(str(file_meta.get('permissions', '644')), base=8)
        with open(path, "w") as f:
            f.write(content)
        os.chmod(path, permissions)

if __name__ == '__main__':
    try:
        main()
    except Exception as e:
        LOG.exception(f"Failed to apply image layout: {e}")
        sys.exit(1)