Re: [PATCH v4 1/2] scripts: add tool to run containerized builds

[Guillaume Tucker <gtucker@gtucker.io>]

Hi Onur,

On 22/01/2026 15:29, Onur Özkan wrote:
> Hi Guillaume,
> 
> Just 2 notes from my end.
> 
> On Thu, 22 Jan 2026 15:06:59 +0100
> Guillaume Tucker <gtucker@gtucker.io> wrote:
> 
>> Add a 'scripts/container' tool written in Python to run any command in
>> the source tree from within a container.  This can typically be used
>> to call 'make' with a compiler toolchain image to run reproducible
>> builds but any arbitrary command can be run too.  Only Docker and
>> Podman are supported in this initial version.
>>
>> Add a new entry to MAINTAINERS accordingly.
>>
>> Cc: Nathan Chancellor <nathan@kernel.org>
>> Cc: Nicolas Schier <nsc@kernel.org>
>> Cc: Miguel Ojeda <ojeda@kernel.org>
>> Cc: David Gow <davidgow@google.com>
>> Cc: "Onur Özkan" <work@onurozkan.dev>
>> Link:
>> https://lore.kernel.org/all/affb7aff-dc9b-4263-bbd4-a7965c19ac4e@gtucker.io/
>> Signed-off-by: Guillaume Tucker <gtucker@gtucker.io> ---
>>  MAINTAINERS       |   6 ++
>>  scripts/container | 199
>> ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 205
>> insertions(+) create mode 100755 scripts/container
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index da9dbc1a4019..affd55ff05e0 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -6384,6 +6384,11 @@ S:	Supported
>>  F:	drivers/video/console/
>>  F:	include/linux/console*
>>  
>> +CONTAINER BUILD SCRIPT
>> +M:	Guillaume Tucker <gtucker@gtucker.io>
>> +S:	Maintained
>> +F:	scripts/container
>> +
>>  CONTEXT TRACKING
>>  M:	Frederic Weisbecker <frederic@kernel.org>
>>  M:	"Paul E. McKenney" <paulmck@kernel.org>
>> @@ -13676,6 +13681,7 @@ F:	scripts/Makefile*
>>  F:	scripts/bash-completion/
>>  F:	scripts/basic/
>>  F:	scripts/clang-tools/
>> +F:	scripts/container
>>  F:	scripts/dummy-tools/
>>  F:	scripts/include/
>>  F:	scripts/mk*
>> diff --git a/scripts/container b/scripts/container
>> new file mode 100755
>> index 000000000000..09663eccb8d3
>> --- /dev/null
>> +++ b/scripts/container
>> @@ -0,0 +1,199 @@
>> +#!/usr/bin/env python3
>> +# SPDX-License-Identifier: GPL-2.0-only
>> +# Copyright (C) 2025 Guillaume Tucker
>> +
>> +"""Containerized builds"""
>> +
>> +import abc
>> +import argparse
>> +import logging
>> +import os
>> +import pathlib
>> +import shutil
>> +import subprocess
>> +import sys
>> +import uuid
>> +
>> +
>> +class ContainerRuntime(abc.ABC):
>> +    """Base class for a container runtime implementation"""
>> +
>> +    name = None  # Property defined in each implementation class
>> +
>> +    def __init__(self, args, logger):
>> +        self._uid = args.uid or os.getuid()
>> +        self._gid = args.gid or args.uid or os.getgid()
>> +        self._env_file = args.env_file
>> +        self._shell = args.shell
>> +        self._logger = logger
>> +
>> +    @classmethod
>> +    def is_present(cls):
>> +        """Determine whether the runtime is present on the system"""
>> +        return shutil.which(cls.name) is not None
>> +
>> +    @abc.abstractmethod
>> +    def _do_run(self, image, cmd, container_name):
>> +        """Runtime-specific handler to run a command in a
>> container""" +
>> +    @abc.abstractmethod
>> +    def _do_abort(self, container_name):
>> +        """Runtime-specific handler to abort a running container"""
>> +
>> +    def run(self, image, cmd):
>> +        """Run a command in a runtime container"""
>> +        container_name = str(uuid.uuid4())
>> +        self._logger.debug("container: %s", container_name)
>> +        try:
>> +            return self._do_run(image, cmd, container_name)
>> +        except KeyboardInterrupt:
>> +            self._logger.error("user aborted")
>> +            self._do_abort(container_name)
>> +            return 1
>> +
>> +
>> +class CommonRuntime(ContainerRuntime):
>> +    """Common logic for Docker and Podman"""
>> +
>> +    def _do_run(self, image, cmd, container_name):
>> +        cmdline = [self.name, 'run']
>> +        cmdline += self._get_opts(container_name)
>> +        cmdline.append(image)
>> +        cmdline += cmd
>> +        self._logger.debug('command: %s', ' '.join(cmdline))
>> +        return subprocess.call(cmdline)
>> +
>> +    def _get_opts(self, container_name):
>> +        opts = [
>> +            '--name', container_name,
>> +            '--rm',
>> +            '--volume', f'{pathlib.Path.cwd()}:/src',
>> +            '--workdir', '/src',
>> +        ]
>> +        if self._env_file:
>> +            opts += ['--env-file', self._env_file]
>> +        if self._shell:
>> +            opts += ['--interactive', '--tty']
>> +        return opts
>> +
>> +    def _do_abort(self, container_name):
>> +        subprocess.call([self.name, 'kill', container_name])
>> +
>> +
>> +class DockerRuntime(CommonRuntime):
>> +    """Run a command in a Docker container"""
>> +
>> +    name = 'docker'
>> +
>> +    def _get_opts(self, container_name):
>> +        return super()._get_opts(container_name) + [
>> +            '--user', f'{self._uid}:{self._gid}'
>> +        ]
>> +
>> +
>> +class PodmanRuntime(CommonRuntime):
>> +    """Run a command in a Podman container"""
>> +
>> +    name = 'podman'
>> +
>> +    def _get_opts(self, container_name):
>> +        return super()._get_opts(container_name) + [
>> +            '--userns', f'keep-id:uid={self._uid},gid={self._gid}',
>> +        ]
>> +
>> +
>> +class Runtimes:
>> +    """List of all supported runtimes"""
>> +
>> +    runtimes = [PodmanRuntime, DockerRuntime]
>> +
>> +    @classmethod
>> +    def get_names(cls):
>> +        """Get a list of all the runtime names"""
>> +        return list(runtime.name for runtime in cls.runtimes)
>> +
>> +    @classmethod
>> +    def get(cls, name):
>> +        """Get a single runtime class matching the given name"""
>> +        for runtime in cls.runtimes:
>> +            if runtime.name == name:
>> +                if not runtime.is_present():
>> +                    raise ValueError(f"runtime not found: {name}")
>> +                return runtime
>> +        raise ValueError(f"unknown runtime: {runtime}")
>> +
> 
> I think you meant to use "{name}" not "{runtime}" inside ValueError.

Ah yes, sorry.  The parser already checks that the runtime name is in
the list so I've never hit this error.  We would probably need some
unit tests at some point.

So yes this fixes the issue, which can be reproduced with a small
hack in the script to relax the -r option checks:

--- a/scripts/container
+++ b/scripts/container
@@ -120,7 +120,7 @@ class Runtimes:
                 if not runtime.is_present():
                     raise ValueError(f"runtime not found: {name}")
                 return runtime
-        raise ValueError(f"unknown runtime: {runtime}")
+        raise ValueError(f"unknown runtime: {name}")
 
     @classmethod
     def find(cls):


Nathan, would you be OK with folding this in or should I send a v5?

>> +    @classmethod
>> +    def find(cls):
>> +        """Find the first runtime present on the system"""
>> +        for runtime in cls.runtimes:
>> +            if runtime.is_present():
>> +                return runtime
>> +        raise ValueError("no runtime found")
>> +
> 
> nit: We could extend the error message like: "Couldn't find any runtime.
> Use -r <runtime> to specify one manually". What do you think?

I'm all for improving the user experience.  It's good to keep the
implementation logic separate from the command line interface though.
Maybe this is something I could improve in a follow-up?  There are a
few other potential things to rework in this area; a more detailed
error could be logged in main().

>> +
>> +def _get_logger(verbose):
>> +    """Set up a logger with the appropriate level"""
>> +    logger = logging.getLogger('container')
>> +    handler = logging.StreamHandler()
>> +    handler.setFormatter(logging.Formatter(
>> +        fmt='[container {levelname}] {message}', style='{'
>> +    ))
>> +    logger.addHandler(handler)
>> +    logger.setLevel(logging.DEBUG if verbose is True else
>> logging.INFO)
>> +    return logger
>> +
>> +
>> +def main(args):
>> +    """Main entry point for the container tool"""
>> +    logger = _get_logger(args.verbose)
>> +    try:
>> +        cls = Runtimes.get(args.runtime) if args.runtime else
>> Runtimes.find()
>> +    except ValueError as ex:
>> +        logger.error(ex)
>> +        return 1
>> +    logger.debug("runtime: %s", cls.name)
>> +    logger.debug("image: %s", args.image)
>> +    return cls(args, logger).run(args.image, args.cmd)
>> +
>> +
>> +if __name__ == '__main__':
>> +    parser = argparse.ArgumentParser(
>> +        'container',
>> +        description="See the documentation for more details: "
>> +        "https://docs.kernel.org/dev-tools/container.html"
>> +    )
>> +    parser.add_argument(
>> +        '-e', '--env-file',
>> +        help="Path to an environment file to load in the container."
>> +    )
>> +    parser.add_argument(
>> +        '-g', '--gid',
>> +        help="Group ID to use inside the container."
>> +    )
>> +    parser.add_argument(
>> +        '-i', '--image', required=True,
>> +        help="Container image name."
>> +    )
>> +    parser.add_argument(
>> +        '-r', '--runtime', choices=Runtimes.get_names(),
>> +        help="Container runtime name.  If not specified, the first
>> one found "
>> +        "on the system will be used i.e. Podman if present,
>> otherwise Docker."
>> +    )
>> +    parser.add_argument(
>> +        '-s', '--shell', action='store_true',
>> +        help="Run the container in an interactive shell."
>> +    )
>> +    parser.add_argument(
>> +        '-u', '--uid',
>> +        help="User ID to use inside the container.  If the -g option
>> is not "
>> +        "specified, the user ID will also be set as the group ID."
>> +    )
>> +    parser.add_argument(
>> +        '-v', '--verbose', action='store_true',
>> +        help="Enable verbose output."
>> +    )
>> +    parser.add_argument(
>> +        'cmd', nargs='+',
>> +        help="Command to run in the container"
>> +    )
>> +    sys.exit(main(parser.parse_args(sys.argv[1:])))
> 
> The rest LGTM.

Thanks for the reviews.

Cheers,
Guillaume