Initial commit

.gitignore

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+.mypy_cache/
+/.venv
+/build/
+/dist/
+__pycache__/
+*.egg-info/
+*.py[co]
+/kernel.img
+src/ocivm/kernel.img

.gitmodules

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+[submodule "kernel"]
+	path = kernel
+	url = https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

MANIFEST.in

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+include src/ocivm/kernel.img
+include src/ocivm/linuxrc

Makefile

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+VERSION = $(shell .venv/bin/python -m setuptools_scm)
+
+wheel: dist/ocivm-$(VERSION)-py3-none-any.whl
+
+.venv:
+	python3 -m venv .venv
+
+venv: .venv
+
+dev: .venv
+	.venv/bin/python -m pip install -r dev-requirements.txt
+
+dist/ocivm-$(VERSION)-py3-none-any.whl: \
+		$(shell find src -type f -name '*.py') \
+		src/ocivm/kernel.img \
+		MANIFEST.in \
+		pyproject.toml
+ifeq ($(VERSION),)
+	$(error Run make dev first)
+endif
+	.venv/bin/python -m build
+
+kernel: src/ocivm/kernel.img
+
+src/ocivm/kernel.img: kconfig
+	cp -uv kconfig kernel/.config
+	$(MAKE) -C kernel
+	cp -uv kernel/arch/x86/boot/bzImage src/ocivm/kernel.img
+
+clean:
+	$(MAKE) -C kernel mrproper
+	rm -rf .venv
+	rm -rf build dist
+	rm -f src/ocivm/kernel.img
+
+
+.PHONY: \
+	clean \
+	dev \
+	kernel \
+	venv \
+	wheel

README.md

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+# ocivm
+
+Create and run virtual machines from OCI container images.
+
+
+## Dependencies
+
+* [*buildah*][0]
+* [*guestfs-tools*][1] (`virt-make-fs`)
+* [*qemu*][2] >= 4.2
+
+[0]: https://buildah.io/
+[1]: https://libguestfs.org/
+[2]: https://www.qemu.org/

dev-requirements.txt

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+build
+setuptools_scm[toml]>=6.2
+-e .

kernel

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+Subproject commit 1ac8758e027247774464c808447a9c2f1f97b637

pyproject.toml

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+[project]
+name = 'ocivm'
+authors = [
+    {name = 'Dustin C. Hatch'},
+]
+description = 'Run an OCI container image as a QEMU microvm'
+license = {text = 'Apache-2.0 OR MIT'}
+dynamic = ['version']
+requires-python = '>=3.10'
+dependencies = [
+    'rich',
+    'xdg',
+]
+
+[project.scripts]
+ocivm = 'ocivm.cli:main'
+
+[build-system]
+requires = ['setuptools>=45', 'setuptools-scm[toml]>=6.2']
+build-backend = 'setuptools.build_meta'
+
+[tool.setuptools_scm]
+
+[tool.black]
+line-length = 79
+skip-string-normalization = true
+
+[tool.isort]
+line_length = 79
+ensure_newline_before_comments = true
+force_grid_wrap = 0
+include_trailing_comma = true
+lines_after_imports = 2
+multi_line_output = 3
+use_parentheses = true
+
+[tool.pyright]
+venvPath = '.'
+venv = '.venv'
+pythonVersion = '3.10'

src/ocivm/__main__.py

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+from ocivm.cli import main
+main()

src/ocivm/cli.py

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+import argparse
+import logging
+import tempfile
+from pathlib import Path
+
+import rich.console
+import rich.logging
+import xdg
+
+from ocivm import image
+
+
+log = logging.getLogger(__name__)
+
+
+class CLI:
+    def __init__(self, console: rich.console.Console) -> None:
+        self.console = console
+
+    def image_dir(self) -> Path:
+        image_dir = xdg.xdg_data_home() / 'ocivm' / 'images'
+        log.debug('Using image storage directory %s', image_dir)
+        return image_dir
+
+    def import_image(self, name: str) -> None:
+        img = self.image_dir() / name
+        img.parent.mkdir(parents=True, exist_ok=True)
+        img = img.with_suffix('.qcow2')
+        with tempfile.NamedTemporaryFile(suffix='.tar') as tmp_tar:
+            with self.console.status('Exporting OCI image as tarball ...'):
+                tar = Path(tmp_tar.name)
+                image.make_tar(name, tar)
+                self.console.print('Created tarball:', tar)
+            with self.console.status('Converting tarball to QCOW2 image ...'):
+                image.tar2qcow2(tar, img)
+                self.console.print('Created QCOW2 image:', img)
+
+
+def parse_args() -> argparse.Namespace:
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        '--quiet',
+        '-q',
+        action='store_true',
+        default=False,
+        help='Suppress CLI output',
+    )
+    parser.add_argument(
+        '--log-level',
+        default='INFO',
+        choices=('CRITICAL', 'ERROR', 'WARNING', 'INFO', 'DEBUG'),
+        help='Set CLI log level',
+    )
+    sp = parser.add_subparsers(dest='command', required=True)
+
+    p_import = sp.add_parser('import', help='Import container image')
+    p_import.add_argument('name', help='Container image name')
+
+    return parser.parse_args()
+
+
+def main() -> None:
+    args = parse_args()
+    console = rich.console.Console(stderr=True, quiet=args.quiet)
+    logging.basicConfig(
+        level=logging.getLevelName(args.log_level),
+        format='%(message)s',
+        datefmt='[%X]',
+        handlers=[rich.logging.RichHandler(console=console)],
+    )
+    cli = CLI(console)
+    match args.command:
+        case 'import':
+            cli.import_image(args.name)

src/ocivm/image.py

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+import importlib.resources
+import logging
+import string
+import subprocess
+import tempfile
+from pathlib import Path
+
+from .util import list2cmdline
+
+
+log = logging.getLogger(__name__)
+
+
+CONTAINERFILE_TMPL = string.Template(
+    '''\
+FROM ${name}
+ADD linuxrc /
+'''
+)
+
+
+def make_tar(name: str, dest: Path) -> None:
+    res = importlib.resources.files(__package__).joinpath('linuxrc')
+    with tempfile.TemporaryDirectory() as t:
+        log.debug('Using temporary directory %s', t)
+        log.debug('Copying linuxrc to temporary directory')
+        with res.open('rb') as f:
+            path = Path(t) / 'linuxrc'
+            with path.open('wb') as o:
+                sz = 0
+                while d := f.read(4096):
+                    sz += o.write(d)
+            log.debug('Wrote %d bytes', sz)
+        containerfile = CONTAINERFILE_TMPL.safe_substitute(name=name)
+        path = Path(t) / 'Containerfile'
+        with path.open('w', encoding='utf-8') as f:
+            f.write(containerfile)
+        cmd = [
+            'buildah',
+            'build',
+            '--layers',
+            '--output',
+            f'type=tar,dest={dest}',
+            t,
+        ]
+        if log.isEnabledFor(logging.DEBUG):
+            log.debug('Running command: %s', list2cmdline(cmd))
+        subprocess.run(
+            cmd,
+            stdin=subprocess.DEVNULL,
+            capture_output=True,
+            check=True,
+        )
+
+
+def tar2qcow2(src: Path, dest: Path, size: str = '+1G') -> None:
+    raw = dest.with_suffix('.img')
+    cmd = [
+        'virt-make-fs',
+        '-F',
+        'raw',
+        '-t',
+        'ext4',
+        '--size',
+        size,
+        src,
+        raw,
+    ]
+    subprocess.run(
+        cmd,
+        stdin=subprocess.DEVNULL,
+        check=True,
+    )
+    cmd = [
+        'qemu-img',
+        'convert',
+        '-O',
+        'qcow2',
+        raw,
+        dest,
+    ]
+    subprocess.run(
+        cmd,
+        stdin=subprocess.DEVNULL,
+        check=True,
+    )
+    raw.unlink()

src/ocivm/linuxrc

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+#!/bin/sh
+# vim: set sw=4 ts=4 sts=4 et :
+
+mkdir -p \
+    /dev \
+    /proc \
+    /run \
+    /sys \
+    /tmp
+
+mountpoint -q /dev || mount -t devtmpfs devtmpfs /dev
+mkdir -p /dev/pts /dev/shm
+mount -t devpts devpts /dev/pts
+mount -t tmpfs tmpfs /dev/shm
+ln -s /proc/self/fd /dev/fd
+mount -t proc proc /proc
+mount -t sysfs sysfs /sys
+mount -t tmpfs tmpfs /tmp
+mount -t tmpfs tmpfs /run
+
+mkdir -p /tmp/build
+mount -t 9p -o trans=virtio,version=9p2000.L,msize=52428800 hostfiles /tmp/build
+
+ip link set eth0 up
+ip address add 192.168.76.8/24 dev eth0
+ip route add default via 192.168.76.2
+echo nameserver 192.168.76.3 > /etc/resolv.conf
+
+cd /tmp/build
+exec /bin/bash
+
+echo 1 > /proc/sys/kernel/sysrq
+echo b > /proc/sysrq-trigger

src/ocivm/util.py

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+import shlex
+from typing import Any
+
+
+def list2cmdline(args: list[Any]) -> str:
+    return ' '.join(shlex.quote(a) for a in args)