Files
mcp-server/spark_executor/tools/submit.py
T
Claude 34e6208f54 feat: SQL safety policy (SELECT/INSERT only) at submit time
The agent can now write PySpark that runs DROP/DELETE/UPDATE/etc. on
production tables. Add a static guard that rejects anything other than
SELECT and INSERT at two enforcement points:

  1. generate_job_file: validates BEFORE writing to disk. Agent gets
     immediate feedback ('rewrite to use only SELECT/INSERT') rather
     than learning at submit time.

  2. prepare_submit_job: re-validates the script content (reads the
     file) as a defense-in-depth check. Catches host-mounted files,
     manually-edited files, anything that bypassed generate_job_file.

How it works:
  - common/sql_guard.py extracts Python string literals whose first
    keyword is a SQL verb (catches spark.sql('...'), f-strings, and any
    raw SQL literal)
  - sqlparse splits each literal into statements; we check the first
    keyword against the policy (SELECT/INSERT/WITH allowed; DROP,
    DELETE, UPDATE, TRUNCATE, ALTER, CREATE, REPLACE, MERGE, GRANT,
    REVOKE, SET, SHOW, KILL, EXEC, etc. forbidden)
  - WITH recurses into the CTE body to catch WITH x AS (DROP ...) ...
  - The MCP layer maps ValueError -> HTTP 400 (existing handler)

Test coverage:
  - 28 unit tests in test_sql_guard.py cover: extraction (single/double/
    f-string, English false positives, multi-literal), statement
    classification (SELECT, INSERT, DROP, DELETE, UPDATE, TRUNCATE,
    ALTER, CREATE, multi-statement, CTE bodies, comments)
  - 2 integration tests verify MCP layer returns 400 with the policy
    explanation at both generate_job_file and prepare_submit_job

Limitations (documented in sql_guard.py docstring):
  - f-strings where the SQL is built at runtime (e.g. f'SELECT * FROM
    {user_input}') look like SELECTs at static-analysis time. The
    guard catches the static literal; the runtime substitution is the
    caller's responsibility.
  - pyspark.sql.functions.expr('...') accepts SQL inline; not currently
    caught. (Future work.)

146/146 still pass. Live verified: DROP TABLE -> MCP 400 with policy
explanation; SELECT -> MCP 200 + file written to ./data/jobs/.
2026-06-25 12:52:16 +08:00

235 lines
8.6 KiB
Python

# coding=utf-8
"""
@Time :2026/6/24
@Author :tao.chen
"""
import os
import secrets
import uuid
from datetime import datetime
from common.logging import logger
from common.sql_guard import validate_pyspark_code
from spark_executor.core.connection_store import store as conn_store
from spark_executor.core.job_store import JobStore
from spark_executor.core.log_parser import parse_spark_submit_output
from spark_executor.core.pending_store import store as pending_store
from spark_executor.core.spark_submit import (
SparkSubmitError,
build_spark_submit_command,
run_spark_submit,
)
from spark_executor.models import Job, PendingSubmission, SubmitResult
def _script_path_error(path: str) -> ValueError:
"""Instructive error for an invalid script_path. The MCP client receives
this via the ValueError -> 400 exception handler in server.py."""
return ValueError(
f"script_path does not exist or is not a file: {path!r}. "
f"Two ways to fix this:\n"
f" 1. (Recommended) Call generate_job_file(code=...) first to write "
f"the PySpark source to disk, then pass the returned script_path.\n"
f" 2. If the file already exists on the host, mount it into the "
f"container (e.g. -v /host/path:/app/scripts:ro in docker run) and "
f"pass the in-container path here."
)
def _check_script_path(script_path: str) -> None:
"""Verify script_path points at an existing regular file. Raises ValueError
(-> 400 via the FastAPI exception handler) with an instructive message."""
if not script_path or not os.path.isfile(script_path):
raise _script_path_error(script_path)
def _sql_guard_error(offenses: list[str]) -> ValueError:
"""Instructive 400 error when the script's SQL fails the safety policy."""
return ValueError(
f"Script SQL violates the safety policy. "
f"Only SELECT and INSERT statements are allowed. "
f"Found forbidden statement(s): {offenses}. "
f"Edit the script and try again. (If the code was generated via "
f"generate_job_file, the generator should have caught this — check "
f"for f-string-based SQL injection where the static analysis can't "
f"see the runtime value.)"
)
def _new_pending_id() -> str:
return "p_" + secrets.token_hex(6)
def prepare_submit_job(
*,
connection: str,
script_path: str,
queue: str = "default",
executor_memory: str = "4G",
executor_cores: int = 2,
num_executors: int = 2,
) -> dict[str, object]:
"""Snapshot connection params and persist a PendingSubmission. Does NOT submit."""
logger.debug(
f"prepare_submit_job enter connection={connection} script_path={script_path} "
f"queue={queue} executor_memory={executor_memory} executor_cores={executor_cores} "
f"num_executors={num_executors}"
)
# Order of checks matters for the error the agent sees:
# 1. Unknown connection -> 404 (KeyError -> 404 in server.py)
# 2. Missing script file -> 400 (ValueError -> 400)
# 3. SQL policy violation -> 400 (ValueError -> 400)
# Connection is checked first because it is a more fundamental problem
# (the agent is asking about a cluster that doesn't exist), and the
# agent shouldn't have to fix the script path only to learn the
# connection name is wrong.
conn = conn_store.get(connection)
if conn is None:
raise KeyError(f"Unknown connection: {connection}")
# Fail fast: a non-existent path is the most common agent mistake (it
# generated the code in its own context but forgot to call
# generate_job_file first, or its path refers to the host filesystem
# which is invisible inside the container). Better to surface this with
# a 400 + clear remediation than to let spark-submit fail later with
# an opaque FileNotFoundError -> 500.
_check_script_path(script_path)
# SQL safety: re-validate the script even though generate_job_file
# already guards its own output. Catches files written by other means
# (host volume mounts, manual edits).
with open(script_path, encoding="utf-8") as f:
script_body = f.read()
offenses = validate_pyspark_code(script_body)
if offenses:
logger.warning(
f"prepare_submit_job rejected: SQL policy violation(s) in "
f"{script_path}: {offenses}"
)
raise _sql_guard_error(offenses)
pending_id = _new_pending_id()
pending = PendingSubmission(
pending_id=pending_id,
connection=connection,
master=conn.master,
deploy_mode=conn.deploy_mode,
yarn_rm_url=conn.yarn_rm_url,
script_path=script_path,
queue=queue,
executor_memory=executor_memory,
executor_cores=executor_cores,
num_executors=num_executors,
spark_conf=dict(conn.spark_conf),
created_at=datetime.utcnow(),
status="PENDING",
)
pending_store.save(pending)
logger.info(
f"prepare_submit_job ok pending_id={pending_id} connection={connection} "
f"master={conn.master} script_path={script_path}"
)
return {
"pending_id": pending_id,
"status": "PENDING",
"parameters": pending.model_dump(),
}
# Module-level job store singleton; replaced in tests.
job_store: JobStore = JobStore()
def confirm_submit_job(*, pending_id: str) -> SubmitResult:
"""Actually invoke spark-submit for a previously-prepared PendingSubmission."""
logger.debug(f"confirm_submit_job enter pending_id={pending_id}")
pending = pending_store.get(pending_id)
if pending is None:
raise KeyError(f"Unknown pending_id: {pending_id}")
if pending.status != "PENDING":
raise ValueError(
f"pending_id {pending_id} is in status {pending.status!r}, not PENDING"
)
# Defense in depth: re-verify the script still exists. A user could
# delete the file between prepare and confirm (or an external cleanup
# job could remove it). 400 via the ValueError -> 400 handler.
_check_script_path(pending.script_path)
cmd = build_spark_submit_command(
master=pending.master,
deploy_mode=pending.deploy_mode,
script_path=pending.script_path,
queue=pending.queue,
executor_memory=pending.executor_memory,
executor_cores=pending.executor_cores,
num_executors=pending.num_executors,
spark_conf=pending.spark_conf,
)
logger.info(
f"confirm_submit_job start pending_id={pending_id} "
f"application_target={pending.master} script_path={pending.script_path}"
)
try:
result = run_spark_submit(cmd)
except SparkSubmitError as exc:
pending.status = "FAILED"
pending.error = str(exc)
pending_store.save(pending)
logger.error(f"confirm_submit_job failed pending_id={pending_id} err={exc}")
raise
application_id, tracking_url = parse_spark_submit_output(result.stderr)
job_id = uuid.uuid4().hex[:12]
job_store.put(
Job(
job_id=job_id,
application_id=application_id,
script_path=pending.script_path,
queue=pending.queue,
submit_time=datetime.utcnow(),
connection=pending.connection,
yarn_rm_url=pending.yarn_rm_url,
)
)
pending.status = "SUBMITTED"
pending.job_id = job_id
pending.application_id = application_id
pending_store.save(pending)
logger.info(
f"confirm_submit_job ok pending_id={pending_id} job_id={job_id} "
f"application_id={application_id}"
)
return SubmitResult(
job_id=job_id,
application_id=application_id,
tracking_url=tracking_url,
)
def list_pending_jobs() -> list[dict[str, object]]:
logger.debug("list_pending_jobs enter")
return [p.model_dump() for p in pending_store.list_all()]
def get_pending_job(pending_id: str) -> dict[str, object]:
logger.debug(f"get_pending_job enter pending_id={pending_id}")
p = pending_store.get(pending_id)
if p is None:
raise KeyError(f"Unknown pending_id: {pending_id}")
return p.model_dump()
def cancel_pending_job(pending_id: str) -> dict[str, str]:
logger.debug(f"cancel_pending_job enter pending_id={pending_id}")
p = pending_store.get(pending_id)
if p is None:
raise KeyError(f"Unknown pending_id: {pending_id}")
if p.status in ("SUBMITTED", "FAILED"):
raise ValueError(
f"pending_id {pending_id} is in status {p.status!r} and cannot be cancelled"
)
p.status = "CANCELLED"
pending_store.save(p)
logger.info(f"cancel_pending_job ok pending_id={pending_id}")
return {"pending_id": pending_id, "status": "CANCELLED"}