diskimage-builder/diskimage_builder/elements/dracut-regenerate/finalise.d/50-dracut-regenerate

#!/usr/local/bin/dib-python

# Copyright 2017 Red Hat, 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.

import os
import re
import subprocess
import yaml


def main():
    dracut_env = os.getenv('DIB_DRACUT_ENABLED_MODULES')
    dracut_objects = yaml.safe_load(dracut_env)

    modules_to_boot = []
    for dracut_object in dracut_objects:
        # first, install dependent packages
        packages = dracut_object.get('packages', [])
        for package in packages:
            cmdline = ["install-packages", package]
            subp = subprocess.Popen(cmdline, stdout=subprocess.PIPE)
            out = subp.communicate()[0]
            if subp.returncode:
                e = subprocess.CalledProcessError(subp.returncode, cmdline)
                e.output = out
                raise e

        # second, compose the list of modules to boot
        modules_to_boot.append(dracut_object.get('name', None))

    # regenerate dracut with the list of installed modules
    if len(modules_to_boot) > 0:
        cmdline = ["select-boot-kernel-initrd"]
        subp = subprocess.Popen(cmdline, stdout=subprocess.PIPE)
        out, err = subp.communicate()

        if subp.returncode:
            e = subprocess.CalledProcessError(subp.returncode, cmdline)
            e.output = out
            raise e

        kernel_set = out.decode().split(':')
        kernel_search = re.match("vmlinuz-(.*)", kernel_set[0])
        kernel_version = "%s" % kernel_search.groups(1)
        ramdisk_path = "/boot/%s" % kernel_set[1].strip()
        modules_to_boot = ' ' .join(modules_to_boot)

        subp = subprocess.Popen(['dracut', '--force', '--add', modules_to_boot,
                                 '-f', ramdisk_path, kernel_version],
                                stdout=subprocess.PIPE)
        subp.wait()


if __name__ == '__main__':
    main()