Recover from a known-good image

import asyncio
from contree_sdk import Contree


async def main() -> None:
    client = Contree()
    base = await client.images.oci("docker.io/library/alpine:3.19")
    checkpoint = await base.run(
        shell="mkdir -p /work && printf 'known-good\\n' > /work/state.txt",
        disposable=False, timeout=30,
    )
    if checkpoint.exit_code != 0 or checkpoint.uuid is None:
        raise RuntimeError('Preparation failed or returned no saved checkpoint')
    known_good_uuid = checkpoint.uuid
    print(f"Saved known-good checkpoint: {known_good_uuid}")

    known_good = await client.images.use(known_good_uuid, strict=True)
    failed = await known_good.run(
        shell="test \"$(cat /work/state.txt)\" = wrong-value",
        disposable=True, timeout=30,
    )
    if failed.exit_code == 0:
        raise RuntimeError('The intentionally wrong check unexpectedly passed')
    print(f"deliberate failure exit={failed.exit_code} stderr={failed.stderr!r}")

    retry_base = await client.images.use(known_good_uuid, strict=True)
    recovered = await retry_base.run(
        shell="test \"$(cat /work/state.txt)\" = known-good && printf 'recovered\\n'",
        disposable=True, timeout=30,
    )
    if recovered.exit_code != 0 or recovered.stdout != "recovered\n":
        raise RuntimeError('Retry did not produce the expected recovered output')
    print(f"checkpoint={known_good_uuid} recovered")


asyncio.run(main())