didericis
c276f7b0b1
Adds a Firecracker-based backend for Linux, providing mature KVM-based microVM isolation to replace smolmachines/libkrun (issue #342, closes the dead-end tracked in #332). Architecture: - Guest control over SSH (dropbear injected into the rootfs) on a point-to-point TAP link. `ssh -t` forwards SIGWINCH natively, so no resize bridge is needed. - Networking: a one-time, root-provisioned pool of user-owned TAP devices (no shared bridge → no docker0/virbr0/cni0 collisions) plus a dedicated `table inet bot_bottle_fc` nftables table (independent of Docker/ufw/firewalld rules). `./cli.py firecracker setup` prints the host-appropriate config (NixOS module or sudo script). - Rootfs: `docker export` → ext4 via `mke2fs -d` (rootless, no mount), cached by image digest; per-bottle SSH pubkey + IP passed via the kernel cmdline. - Sidecar: reuses the Docker bundle, published on the slot's host TAP IP. - Fail-closed isolation: TAP pool verified at preflight; the egress boundary is proven empirically post-boot (before the agent runs) by a canary probe — the VM must fail to reach the host directly, or launch is refused. Linux hosts with Firecracker + KVM now default to this backend; macOS stays on macos-container. Not yet validated end-to-end on live hardware (requires the one-time network pool). Unit tests + pyright pass. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01G8p32HJgPoS1hLPWubbftM
91 lines
2.5 KiB
Python
91 lines
2.5 KiB
Python
"""Cleanup for the Firecracker backend.
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Orphans are: firecracker VMM processes whose config lives under our run
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dir, the `bot-bottle-sidecars-*` containers, and the per-bottle run
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dirs. TAP slots free themselves (the flock drops when the launcher
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exits), so there is nothing to reclaim there.
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"""
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from __future__ import annotations
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import os
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import shutil
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import signal
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import subprocess
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from pathlib import Path
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from ...log import info
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from . import util
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from .bottle_cleanup_plan import FirecrackerBottleCleanupPlan
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_SIDECAR_PREFIX = "bot-bottle-sidecars-"
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def _run_root() -> Path:
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return util.cache_dir() / "run"
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def _orphan_vm_pids() -> list[int]:
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"""firecracker processes whose --config-file is under our run dir."""
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run_root = str(_run_root())
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result = subprocess.run(
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["pgrep", "-a", "firecracker"],
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capture_output=True, text=True, check=False,
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)
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if result.returncode != 0:
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return []
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pids: list[int] = []
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for line in result.stdout.splitlines():
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parts = line.split(None, 1)
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if len(parts) != 2 or run_root not in parts[1]:
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continue
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try:
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pids.append(int(parts[0]))
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except ValueError:
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continue
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return pids
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def _sidecar_containers() -> list[str]:
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result = subprocess.run(
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["docker", "ps", "-a", "--format", "{{.Names}}",
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"--filter", f"name={_SIDECAR_PREFIX}"],
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capture_output=True, text=True, check=False,
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)
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if result.returncode != 0:
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return []
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return sorted(n.strip() for n in result.stdout.splitlines() if n.strip())
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def _run_dirs() -> list[str]:
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run_root = _run_root()
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if not run_root.is_dir():
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return []
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return sorted(str(p) for p in run_root.iterdir() if p.is_dir())
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def prepare_cleanup() -> FirecrackerBottleCleanupPlan:
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return FirecrackerBottleCleanupPlan(
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vm_pids=tuple(_orphan_vm_pids()),
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containers=tuple(_sidecar_containers()),
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run_dirs=tuple(_run_dirs()),
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)
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def cleanup(plan: FirecrackerBottleCleanupPlan) -> None:
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for pid in plan.vm_pids:
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info(f"kill firecracker VM pid {pid}")
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try:
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os.kill(pid, signal.SIGTERM)
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except ProcessLookupError:
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pass
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for name in plan.containers:
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info(f"docker rm -f {name}")
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subprocess.run(
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["docker", "rm", "-f", name],
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stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, check=False,
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)
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for path in plan.run_dirs:
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info(f"rm -rf {path}")
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shutil.rmtree(path, ignore_errors=True)
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