congsh
ba6e7669e8
Features: - FastAPI + SQLAlchemy 2.0 async + PostgreSQL/pgvector + Redis backend - Vue 3 + TypeScript + Element Plus frontend - JWT auth with access/refresh tokens and revocation - Admin/member RBAC - RSS feed CRUD and article listing - Settings management with Fernet encryption for sensitive values - Redis distributed lock service - Alembic initial migration - Docker Compose development environment Fixes from code review: - Fix DB session leak in dependency injection - Restrict registration to admin only - Add default admin password warning - Implement JWT refresh tokens and jti blacklist - Strengthen password policy - Use func.count for pagination totals - Replace NullPool with AsyncAdaptedQueuePool - Remove init_db from lifespan to enforce alembic migrations - Add request_id middleware and logging filter - Fix vite.config.ts env loading - Add frontend token refresh interceptor - Add Vue error handler Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
154 lines
5.0 KiB
Python
154 lines
5.0 KiB
Python
"""Distributed lock service with Redis and DB fallback."""
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from datetime import datetime, timedelta, timezone
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from uuid import uuid4
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from sqlalchemy import select
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from sqlalchemy.ext.asyncio import AsyncSession
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from app.core.database import AsyncSessionLocal
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from app.core.logging import get_logger
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from app.core.redis import get_redis
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from app.models.lock import Lock
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logger = get_logger(__name__)
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class LockService:
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"""Distributed lock service."""
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def __init__(self, owner_id: str | None = None):
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self.owner_id = owner_id or str(uuid4())
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async def acquire(self, lock_name: str, ttl: int = 60) -> bool:
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"""Acquire a lock with given TTL in seconds."""
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# Try Redis first
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try:
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redis = await get_redis()
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acquired = await redis.set(lock_name, self.owner_id, nx=True, ex=ttl)
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if acquired:
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return True
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except Exception as exc:
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logger.warning("Redis lock failed, falling back to DB: %s", exc)
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# Fallback to DB
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return await self._acquire_db(lock_name, ttl)
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async def release(self, lock_name: str) -> bool:
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"""Release a lock."""
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# Try Redis first
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try:
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redis = await get_redis()
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# Only release if we own it
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current_owner = await redis.get(lock_name)
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if current_owner == self.owner_id:
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await redis.delete(lock_name)
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return True
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except Exception as exc:
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logger.warning("Redis unlock failed, falling back to DB: %s", exc)
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return await self._release_db(lock_name)
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async def extend(self, lock_name: str, ttl: int = 60) -> bool:
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"""Extend lock TTL."""
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try:
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redis = await get_redis()
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current_owner = await redis.get(lock_name)
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if current_owner == self.owner_id:
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await redis.expire(lock_name, ttl)
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return True
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except Exception as exc:
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logger.warning("Redis extend failed: %s", exc)
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return await self._extend_db(lock_name, ttl)
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async def is_locked(self, lock_name: str) -> bool:
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"""Check if a lock is held."""
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try:
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redis = await get_redis()
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exists = await redis.exists(lock_name)
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if exists:
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return True
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except Exception:
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pass
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async with AsyncSessionLocal() as db:
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result = await db.execute(select(Lock).where(Lock.lock_name == lock_name))
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lock = result.scalar_one_or_none()
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if not lock:
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return False
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if lock.expires_at and lock.expires_at < datetime.now(timezone.utc):
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return False
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return True
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async def _acquire_db(self, lock_name: str, ttl: int) -> bool:
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async with AsyncSessionLocal() as db:
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now = datetime.now(timezone.utc)
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expires_at = now + timedelta(seconds=ttl)
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# Try to update expired lock
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result = await db.execute(
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select(Lock).where(
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Lock.lock_name == lock_name,
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Lock.expires_at < now,
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)
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)
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lock = result.scalar_one_or_none()
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if lock:
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lock.owner_id = self.owner_id
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lock.acquired_at = now
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lock.expires_at = expires_at
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await db.commit()
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return True
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# Try to insert new lock
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lock = Lock(
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lock_name=lock_name,
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owner_id=self.owner_id,
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acquired_at=now,
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expires_at=expires_at,
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)
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db.add(lock)
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try:
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await db.commit()
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return True
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except Exception:
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await db.rollback()
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return False
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async def _release_db(self, lock_name: str) -> bool:
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async with AsyncSessionLocal() as db:
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result = await db.execute(
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select(Lock).where(
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Lock.lock_name == lock_name,
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Lock.owner_id == self.owner_id,
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)
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)
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lock = result.scalar_one_or_none()
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if not lock:
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return False
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await db.delete(lock)
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await db.commit()
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return True
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async def _extend_db(self, lock_name: str, ttl: int) -> bool:
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async with AsyncSessionLocal() as db:
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result = await db.execute(
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select(Lock).where(
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Lock.lock_name == lock_name,
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Lock.owner_id == self.owner_id,
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)
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)
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lock = result.scalar_one_or_none()
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if not lock:
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return False
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lock.expires_at = datetime.now(timezone.utc) + timedelta(seconds=ttl)
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await db.commit()
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return True
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async def get_lock_service(owner_id: str | None = None) -> LockService:
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"""Get a lock service instance."""
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return LockService(owner_id=owner_id)
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