debian-bootc-base-images/bootc-base-imagectl

#!/usr/bin/env python3

import os
import os.path as path
import subprocess
import shutil
import stat
import json
import argparse
import sys
import tempfile

MANIFESTDIR = 'usr/share/doc/bootc-base-imagectl/manifests'

def run_build_rootfs(args):
    """
    Regenerates a base image using a build configuration.
    """
    target = args.target
    if os.path.isdir(args.manifest):
        manifest_path = os.path.join(f'/{MANIFESTDIR}', args.manifest, 'manifest.yaml')
    else:
        manifest_path = f'/{MANIFESTDIR}/{args.manifest}.yaml'

    tmp_manifest = None
    if args.install:
        additional_pkgs = set(args.install)
        if len(additional_pkgs) > 0:
            final_manifest = {
                "include": manifest_path,
                "packages": list(additional_pkgs),
            }
            tmp_manifest = tempfile.NamedTemporaryFile(mode='w', encoding='utf-8', suffix='.json', delete_on_close=False)
            json.dump(final_manifest, tmp_manifest)
            tmp_manifest.close()
            manifest_path = tmp_manifest.name

    rpmostree_argv = ['rpm-ostree', 'compose', 'rootfs']
    try:
        # Assume we can mutate alternative roots
        if args.source_root != '/':
            rpmostree_argv.append(f'--source-root-rw={args.source_root}')
        else:
            # But we shouldn't need to mutate the default root
            rpmostree_argv.append('--source-root=/')
        rpmostree_argv.extend([manifest_path, target])
        # Perform the build
        subprocess.run(rpmostree_argv, check=True)
        # Work around https://github.com/coreos/rpm-ostree/pull/5322
        root_mode = os.lstat(target).st_mode
        if (root_mode & stat.S_IXOTH) == 0:
            print("Updating rootfs mode")
            os.chmod(target, root_mode | (0o555))
        # And run the bootc linter for good measure
        subprocess.run([
            'bootc',
            'container',
            'lint',
            f'--rootfs={target}',
        ], check=True)
    except subprocess.CalledProcessError as e:
        print(f"Error executing command: {e}")
        sys.exit(1)
    finally:
        if tmp_manifest is not None:
            del tmp_manifest

    # Copy our own build configuration into the target if configured;
    # this is used for the first stage build. But by default *secondary*
    # builds don't get this.
    if args.reinject:
        for d in [MANIFESTDIR]:
            dst = path.join(target, d)
            print(f"Copying /{d} to {dst}")
            shutil.copytree('/' + d, dst, symlinks=True)
        for f in ['usr/libexec/bootc-base-imagectl']:
            dst = path.join(target, f)
            print(f"Copying /{f} to {dst}")
            shutil.copy('/' + f, dst)

def run_rechunk(args):
    argv = [
            'rpm-ostree',
            'experimental',
            'compose',
            'build-chunked-oci']
    if args.max_layers is not None:
        argv.append(f"--max-layers={args.max_layers}")
    argv.extend(['--bootc',
            '--format-version=1',
            f'--from={args.from_image}',
            f'--output=containers-storage:{args.to_image}'])
    try:
        subprocess.run(argv, check=True)
    except subprocess.CalledProcessError as e:
        print(f"Error executing command: {e}")
        sys.exit(1)

def run_list(args):
    d = '/' + MANIFESTDIR
    for ent in sorted(os.listdir(d)):
        name, ext = os.path.splitext(ent)
        if ext != '.yaml':
            continue
        fullpath = os.path.join(d, ent)
        if os.path.islink(fullpath):
            continue
        o = subprocess.check_output(['rpm-ostree', 'compose', 'tree', '--print-only', fullpath])
        manifest = json.loads(o)
        description = manifest['metadata']['summary']
        print(f"{name}: {description}")
        print("---")

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Operate on the build configuration for this container")
    parser.add_argument("--args-file", help="File containing arguments to parse (one argument per line)", metavar='FILE')
    subparsers = parser.add_subparsers(help='Subcommands', required=True)

    build_rootfs = subparsers.add_parser('build-rootfs', help='Generate a container root filesystem')
    build_rootfs.add_argument("--reinject", help="Also reinject the build configurations into the target", action='store_true')
    build_rootfs.add_argument("--manifest", help="Use the specified manifest", action='store', default='default')
    build_rootfs.add_argument("--install", help="Add a package", action='append', default=[], metavar='PACKAGE')
    build_rootfs.add_argument("source_root", help="Path to the source root directory used for dnf configuration (default=/)", nargs='?', default='/')
    build_rootfs.add_argument("target", help="Path to the target root directory that will be generated.")
    build_rootfs.set_defaults(func=run_build_rootfs)

    cmd_rechunk = subparsers.add_parser('rechunk', help="Generate a new container image with split, reproducible, chunked layers")
    cmd_rechunk.add_argument("--max-layers", help="Configure the number of output layers")
    cmd_rechunk.add_argument("from_image", help="Operate on this image in the container storage")
    cmd_rechunk.add_argument("to_image", help="Output a new image to the container storage")
    cmd_rechunk.set_defaults(func=run_rechunk)

    cmd_list = subparsers.add_parser('list', help='List available manifests')
    cmd_list.set_defaults(func=run_list)

    args = parser.parse_args()
    if args.args_file:
        add_args = []
        with open(args.args_file) as f:
            for line in f:
                add_args += [line.strip()]
        args = parser.parse_args(sys.argv[1:] + add_args)

    args.func(args)