Files
hermes-agent/tools/environments/vercel_sandbox.py
teknium1 4586cde64d chore: mark the deliberate /tmp literals and shrink the lint baseline to one code block
The seventeen remaining literals are container-side paths, AF_UNIX socket-path-limit
candidates on darwin, detection needles, guard regexes and guidance text that tells the
model to avoid /tmp. Each carries an inline `no-tmp: ok — <why>` so the reason lives
next to the line; the baseline keeps only a fenced tree listing where a marker would render.
2026-09-19 10:44:26 -07:00

347 lines
16 KiB
Python

"""Vercel Sandbox execution environment.
Runs commands in Vercel cloud sandboxes through the shared ``BaseEnvironment``
shell contract. With persistence enabled, task-scoped snapshot ids are stored
under ``HERMES_HOME`` and new sandboxes are restored from them on task reuse.
"""
from __future__ import annotations
import contextlib
import logging
import math
import os
import shlex
import threading
import time
from datetime import timedelta
from functools import cache
from pathlib import Path
from typing import TYPE_CHECKING, Any
import httpx
from hermes_constants import get_hermes_home
from tools.environments.base import BaseEnvironment, _load_json_store, _save_json_store
from tools.environments.base_output import _ThreadedProcessHandle
from tools.environments.file_sync import FileSyncManager, iter_sync_files, quoted_rm_command
from tools.environments.remote_common import ensure_lazy_dep
logger = logging.getLogger(__name__)
if TYPE_CHECKING:
from vercel.sandbox import Sandbox, SandboxStatus, WriteFile
DEFAULT_VERCEL_CWD = "/vercel/sandbox"
_DEFAULT_CONTAINER_DISK_MB = 51200
_CREATE_RETRY_ATTEMPTS = 3
_TRANSIENT_STATUS_CODES = frozenset({408, 425, 429, 500, 502, 503, 504})
_RUNNING_WAIT_TIMEOUT = timedelta(seconds=30)
def _ensure_vercel_sdk() -> None:
"""Lazy-install vercel SDK on demand. Idempotent."""
# The SDK (>=0.7) ships default-on telemetry; Hermes policy is opt-in only, so disable it
# before the SDK is imported. setdefault: an explicit user value is never overridden.
os.environ.setdefault("VERCEL_TELEMETRY_DISABLED", "1")
ensure_lazy_dep("terminal.vercel")
def _is_transient_vercel_error(exc: BaseException) -> bool:
"""True when any exception in the cause/context chain looks retryable."""
seen: set[int] = set()
error: BaseException | None = exc
while error is not None and id(error) not in seen:
seen.add(id(error))
codes = (getattr(error, "status_code", None), getattr(getattr(error, "response", None), "status_code", None))
status = next((c for c in codes if isinstance(c, int)), None)
name = type(error).__name__.lower()
if (status in _TRANSIENT_STATUS_CODES
or isinstance(error, (httpx.NetworkError, httpx.ProtocolError, httpx.ReadError))
or "ratelimit" in name or "servererror" in name):
return True
error = error.__cause__ or error.__context__
return False
def _retry_vercel_call(label: str, callback, *, attempts: int):
for attempt in range(1, attempts + 1):
try:
return callback()
except Exception as exc:
if attempt >= attempts or not _is_transient_vercel_error(exc):
raise
logger.warning("Vercel: %s failed (%s); retrying %d/%d", label, exc, attempt, attempts)
time.sleep(0.1 * attempt)
def _result_parts(result: Any) -> tuple[str, int]:
"""(output, returncode) from an SDK command result; tolerates raw strings and older result shapes."""
try:
value = result.output()
except (AttributeError, TypeError):
value = result
if isinstance(value, bytes):
value = value.decode("utf-8", errors="replace")
exit_code = getattr(result, "exit_code" if hasattr(result, "exit_code") else "returncode", None)
return ("" if value is None else str(value)), (exit_code if isinstance(exit_code, int) else 1)
def _snapshot_store() -> Path:
return get_hermes_home() / "vercel_sandbox_snapshots.json"
def _load_snapshots() -> dict:
return _load_json_store(_snapshot_store())
def _store_snapshot(task_id: str, snapshot_id: str) -> None:
if task_id and snapshot_id:
_save_json_store(_snapshot_store(), {**_load_snapshots(), task_id: snapshot_id})
def _delete_snapshot(task_id: str, snapshot_id: str) -> None:
"""Drop the stored id for ``task_id`` only if it still equals ``snapshot_id``."""
snapshots = _load_snapshots()
if task_id and snapshots.get(task_id) == snapshot_id:
snapshots.pop(task_id)
_save_json_store(_snapshot_store(), snapshots)
def _extract_snapshot_id(snapshot: Any) -> str | None:
"""Accept SDK objects or raw dicts; attribute lookup first, then dict keys."""
getters = [lambda k: getattr(snapshot, k, None)] + ([snapshot.get] if isinstance(snapshot, dict) else [])
candidates = (get(key) for get in getters for key in ("snapshot_id", "snapshotId", "id"))
return next((v for v in candidates if isinstance(v, str) and v), None)
@cache
def _sandbox_status_type() -> type[SandboxStatus]:
_ensure_vercel_sdk()
from vercel.sandbox import SandboxStatus
return SandboxStatus
def _is_terminal(status: Any) -> bool:
S = _sandbox_status_type()
return status in {S.ABORTED, S.FAILED, S.STOPPED}
class VercelSandboxEnvironment(BaseEnvironment):
"""Vercel cloud sandbox backend."""
_stdin_mode = "heredoc"
def __init__(self, runtime: str | None = None, cwd: str = DEFAULT_VERCEL_CWD, timeout: int = 60,
cpu: float = 1, memory: int = 5120, disk: int = _DEFAULT_CONTAINER_DISK_MB,
persistent_filesystem: bool = True, task_id: str = "default"):
super().__init__(cwd=cwd, timeout=timeout)
if disk not in {0, _DEFAULT_CONTAINER_DISK_MB}:
raise ValueError(
"Vercel Sandbox does not support configurable container_disk. "
"Use the default shared setting.")
self._persistent, self._task_id, self._requested_cwd = persistent_filesystem, task_id, cwd
self._lock = threading.Lock()
self._sandbox: Sandbox | None = None
self._workspace_root = self._remote_home = DEFAULT_VERCEL_CWD
self._sync_manager: FileSyncManager | None = None
_ensure_vercel_sdk()
from vercel.sandbox import Resources
vcpus, memory_mb = (math.floor(cpu) if cpu > 0 else None), (memory if memory > 0 else None)
self._create_kwargs = {
"timeout": max(timedelta(seconds=max(self.timeout, 0)), timedelta(minutes=5)),
"runtime": runtime or None,
"resources": Resources(vcpus=vcpus, memory=memory_mb) if (vcpus, memory_mb) != (None, None) else None}
self._attach_fresh_sandbox(cwd)
self._sync_manager.sync(force=True)
self.init_session()
def _require_sandbox(self) -> Sandbox:
if self._sandbox is None:
raise RuntimeError("Vercel sandbox is not attached")
return self._sandbox
def _remote_hermes_dir(self) -> str:
return f"{self._remote_home.rstrip('/')}/.hermes"
def _create_sandbox(self) -> Sandbox:
_ensure_vercel_sdk()
from vercel.sandbox import Sandbox
snapshot_id = _load_snapshots().get(self._task_id) if self._persistent and self._task_id else None
if isinstance(snapshot_id, str) and snapshot_id:
try:
source = {"type": "snapshot", "snapshot_id": snapshot_id}
return _retry_vercel_call(
"sandbox restore", lambda: Sandbox.create(**self._create_kwargs, source=source),
attempts=_CREATE_RETRY_ATTEMPTS)
except Exception as exc:
logger.warning("Vercel: failed to restore snapshot %s for task %s; falling back to a fresh sandbox: %s",
snapshot_id, self._task_id, exc)
_delete_snapshot(self._task_id, snapshot_id)
return _retry_vercel_call("sandbox create", lambda: Sandbox.create(**self._create_kwargs),
attempts=_CREATE_RETRY_ATTEMPTS)
def _attach_fresh_sandbox(self, requested_cwd: str) -> None:
"""Create a sandbox, wait until it runs, then wire cwd/home and the file sync manager."""
self._sandbox = self._create_sandbox()
self._wait_for_running()
cwd = self._require_sandbox().sandbox.cwd
self._workspace_root = cwd if cwd.startswith("/") else DEFAULT_VERCEL_CWD
self._remote_home = self._detect_remote_home()
container_base = self._remote_hermes_dir()
self._sync_manager = FileSyncManager(
get_files_fn=lambda: iter_sync_files(container_base),
upload_fn=lambda host_path, remote_path: self._vercel_bulk_upload([(host_path, remote_path)]),
delete_fn=self._vercel_delete,
bulk_upload_fn=self._vercel_bulk_upload, bulk_download_fn=self._vercel_bulk_download)
self.cwd = {"~": self._remote_home, "": self._workspace_root,
DEFAULT_VERCEL_CWD: self._workspace_root}.get(requested_cwd, requested_cwd)
def _detect_remote_home(self) -> str:
try:
result = self._require_sandbox().run_command("sh", ["-lc", 'printf %s "$HOME"'], cwd=self._workspace_root)
except Exception as exc:
logger.debug("Vercel: home detection failed for task %s: %s", self._task_id, exc)
return self._workspace_root
home = _result_parts(result)[0].strip()
return home if home.startswith("/") else self._workspace_root
def _wait_for_running(self, timeout: timedelta = _RUNNING_WAIT_TIMEOUT) -> None:
sandbox, running = self._require_sandbox(), _sandbox_status_type().RUNNING
status = sandbox.status
if status is None or status == running:
return
if _is_terminal(status):
raise RuntimeError(f"Sandbox entered terminal state: {status}")
try:
sandbox.wait_for_status(running, timeout=max(timeout, timedelta(seconds=1)),
poll_interval=timedelta(milliseconds=250))
except TimeoutError as exc:
status = sandbox.status
if _is_terminal(status):
raise RuntimeError(f"Sandbox entered terminal state: {status}") from exc
raise RuntimeError(f"Sandbox did not reach running state (last status: {status})") from exc
@staticmethod
def _close_sandbox_client(sandbox: Sandbox | None) -> None:
with contextlib.suppress(Exception): # None sandbox -> AttributeError -> no-op
sandbox.client.close()
@staticmethod
def _stop_sandbox(sandbox: Sandbox | None) -> None:
with contextlib.suppress(Exception): # None sandbox -> AttributeError -> no-op
try:
sandbox.stop(blocking=True, timeout=timedelta(seconds=15), poll_interval=timedelta(milliseconds=500))
except TypeError: # older SDKs: stop() takes no arguments
sandbox.stop()
def _snapshot_sandbox(self, sandbox: Sandbox) -> None:
if not self._persistent or not self._task_id:
return
try:
snapshot_id = _extract_snapshot_id(sandbox.snapshot())
except Exception as exc:
logger.warning("Vercel: filesystem snapshot failed for task %s: %s", self._task_id, exc)
return
if not snapshot_id:
logger.warning("Vercel: filesystem snapshot for task %s did not return a snapshot id", self._task_id)
return
_store_snapshot(self._task_id, snapshot_id)
logger.info("Vercel: saved filesystem snapshot %s for task %s", snapshot_id, self._task_id)
def _ensure_sandbox_ready(self) -> None:
"""Reuse a healthy sandbox; recreate when refresh fails or it hit a terminal state."""
sandbox = self._sandbox
requested_cwd = self.cwd or self._requested_cwd or DEFAULT_VERCEL_CWD
if sandbox is not None:
try:
sandbox.refresh()
except Exception as exc:
logger.warning("Vercel: sandbox refresh failed for task %s: %s; recreating", self._task_id, exc)
else:
status = sandbox.status
if not _is_terminal(status):
self._wait_for_running()
return
logger.warning("Vercel: sandbox entered state %s for task %s; recreating", status, self._task_id)
self._close_sandbox_client(sandbox)
self._mark_recreated()
self._attach_fresh_sandbox(requested_cwd)
def _run_checked(self, script: str, label: str) -> None:
output, returncode = _result_parts(
self._require_sandbox().run_command("bash", ["-lc", script], cwd=self._workspace_root))
if returncode != 0:
raise RuntimeError(f"Vercel {label} failed: {output.strip()}")
def _vercel_bulk_upload(self, files: list[tuple[str, str]]) -> None:
if not files:
return
payload: list[WriteFile] = [
{"path": remote_path, "content": Path(host_path).read_bytes()} for host_path, remote_path in files]
sandbox = self._require_sandbox()
_retry_vercel_call("write_files", lambda: sandbox.write_files(payload), attempts=3)
def _vercel_delete(self, remote_paths: list[str]) -> None:
if remote_paths:
self._run_checked(quoted_rm_command(remote_paths), "delete")
def _vercel_bulk_download(self, dest_tar_path: Path) -> None:
archive_member = self._remote_hermes_dir().lstrip("/")
remote_tar = f"/tmp/.hermes_sync.{os.getpid()}.tar" # no-tmp: ok — remote sandbox path
sandbox = self._require_sandbox()
try:
# --exclude: live sockets cannot be archived ("socket ignored") and must not fail the download.
self._run_checked(f"tar cf {shlex.quote(remote_tar)} --exclude='*.sock' -C / {shlex.quote(archive_member)}",
"bulk download")
sandbox.download_file(remote_tar, dest_tar_path)
finally:
with contextlib.suppress(Exception):
sandbox.run_command("bash", ["-lc", f"rm -f {shlex.quote(remote_tar)}"], cwd=self._workspace_root)
def _before_execute(self) -> None:
with self._lock:
self._ensure_sandbox_ready()
if self._sync_manager is not None:
self._sync_manager.sync()
def _run_bash(self, cmd_string: str, *, login: bool = False, timeout: int = 120, stdin_data: str | None = None):
"""``timeout`` is enforced by the base ``_wait_for_process`` via ``cancel_fn`` (the SDK has no
per-exec timeout); ``stdin_data`` is already embedded as a heredoc by the base ``execute()``."""
del timeout, stdin_data
sandbox, workspace_root, lock = self._require_sandbox(), self._workspace_root, self._lock
def cancel() -> None:
with lock:
self._stop_sandbox(sandbox)
def exec_fn() -> tuple[str, int]:
return _result_parts(
sandbox.run_command("bash", ["-lc" if login else "-c", cmd_string], cwd=workspace_root))
return _ThreadedProcessHandle(exec_fn, cancel_fn=cancel)
def cleanup(self):
with self._lock:
sandbox, sync_manager = self._sandbox, self._sync_manager
if sandbox is not None and sync_manager is not None:
try:
sync_manager.sync_back()
except Exception as exc:
logger.warning("Vercel: sync_back failed for task %s: %s", self._task_id, exc)
self._sandbox = None
self._sync_manager = None
if sandbox is None:
return
self._snapshot_sandbox(sandbox)
# Always stop the sandbox during cleanup to avoid resource leaks (matches Modal/Daytona).
self._stop_sandbox(sandbox)
self._close_sandbox_client(sandbox)
# ---- BEGIN PLUGIN-COMPAT (revert-scheduled; see COMPAT_MANIFEST.md) ----
# Names external plugins imported from this module before the Sep 2026 decomposition.
# Internal code MUST NOT use these (scripts/check_compat_pointers.py fails CI if it does).
# The whole block is removed by reverting the commit that added it.
from dataclasses import dataclass # noqa: F401,E402
# ---- END PLUGIN-COMPAT ----