"""Background replication worker.""" from __future__ import annotations import json import logging import mimetypes import threading import time from concurrent.futures import ThreadPoolExecutor from dataclasses import dataclass, field from pathlib import Path from typing import Dict, Optional import boto3 from botocore.config import Config from botocore.exceptions import ClientError from boto3.exceptions import S3UploadFailedError from .connections import ConnectionStore, RemoteConnection from .storage import ObjectStorage, StorageError logger = logging.getLogger(__name__) REPLICATION_USER_AGENT = "S3ReplicationAgent/1.0" REPLICATION_CONNECT_TIMEOUT = 5 REPLICATION_READ_TIMEOUT = 30 REPLICATION_MODE_NEW_ONLY = "new_only" REPLICATION_MODE_ALL = "all" @dataclass class ReplicationStats: """Statistics for replication operations - computed dynamically.""" objects_synced: int = 0 objects_pending: int = 0 objects_orphaned: int = 0 bytes_synced: int = 0 last_sync_at: Optional[float] = None last_sync_key: Optional[str] = None def to_dict(self) -> dict: return { "objects_synced": self.objects_synced, "objects_pending": self.objects_pending, "objects_orphaned": self.objects_orphaned, "bytes_synced": self.bytes_synced, "last_sync_at": self.last_sync_at, "last_sync_key": self.last_sync_key, } @classmethod def from_dict(cls, data: dict) -> "ReplicationStats": return cls( objects_synced=data.get("objects_synced", 0), objects_pending=data.get("objects_pending", 0), objects_orphaned=data.get("objects_orphaned", 0), bytes_synced=data.get("bytes_synced", 0), last_sync_at=data.get("last_sync_at"), last_sync_key=data.get("last_sync_key"), ) @dataclass class ReplicationRule: bucket_name: str target_connection_id: str target_bucket: str enabled: bool = True mode: str = REPLICATION_MODE_NEW_ONLY created_at: Optional[float] = None stats: ReplicationStats = field(default_factory=ReplicationStats) def to_dict(self) -> dict: return { "bucket_name": self.bucket_name, "target_connection_id": self.target_connection_id, "target_bucket": self.target_bucket, "enabled": self.enabled, "mode": self.mode, "created_at": self.created_at, "stats": self.stats.to_dict(), } @classmethod def from_dict(cls, data: dict) -> "ReplicationRule": stats_data = data.pop("stats", {}) if "mode" not in data: data["mode"] = REPLICATION_MODE_NEW_ONLY if "created_at" not in data: data["created_at"] = None rule = cls(**data) rule.stats = ReplicationStats.from_dict(stats_data) if stats_data else ReplicationStats() return rule class ReplicationManager: def __init__(self, storage: ObjectStorage, connections: ConnectionStore, rules_path: Path) -> None: self.storage = storage self.connections = connections self.rules_path = rules_path self._rules: Dict[str, ReplicationRule] = {} self._stats_lock = threading.Lock() self._executor = ThreadPoolExecutor(max_workers=4, thread_name_prefix="ReplicationWorker") self.reload_rules() def reload_rules(self) -> None: if not self.rules_path.exists(): self._rules = {} return try: with open(self.rules_path, "r") as f: data = json.load(f) for bucket, rule_data in data.items(): self._rules[bucket] = ReplicationRule.from_dict(rule_data) except (OSError, ValueError) as e: logger.error(f"Failed to load replication rules: {e}") def save_rules(self) -> None: data = {b: rule.to_dict() for b, rule in self._rules.items()} self.rules_path.parent.mkdir(parents=True, exist_ok=True) with open(self.rules_path, "w") as f: json.dump(data, f, indent=2) def check_endpoint_health(self, connection: RemoteConnection) -> bool: """Check if a remote endpoint is reachable and responsive. Returns True if endpoint is healthy, False otherwise. Uses short timeouts to prevent blocking. """ try: config = Config( user_agent_extra=REPLICATION_USER_AGENT, connect_timeout=REPLICATION_CONNECT_TIMEOUT, read_timeout=REPLICATION_READ_TIMEOUT, retries={'max_attempts': 1} ) s3 = boto3.client( "s3", endpoint_url=connection.endpoint_url, aws_access_key_id=connection.access_key, aws_secret_access_key=connection.secret_key, region_name=connection.region, config=config, ) s3.list_buckets() return True except Exception as e: logger.warning(f"Endpoint health check failed for {connection.name} ({connection.endpoint_url}): {e}") return False def get_rule(self, bucket_name: str) -> Optional[ReplicationRule]: return self._rules.get(bucket_name) def set_rule(self, rule: ReplicationRule) -> None: self._rules[rule.bucket_name] = rule self.save_rules() def delete_rule(self, bucket_name: str) -> None: if bucket_name in self._rules: del self._rules[bucket_name] self.save_rules() def _update_last_sync(self, bucket_name: str, object_key: str = "") -> None: """Update last sync timestamp after a successful operation.""" with self._stats_lock: rule = self._rules.get(bucket_name) if not rule: return rule.stats.last_sync_at = time.time() rule.stats.last_sync_key = object_key self.save_rules() def get_sync_status(self, bucket_name: str) -> Optional[ReplicationStats]: """Dynamically compute replication status by comparing source and destination buckets.""" rule = self.get_rule(bucket_name) if not rule: return None connection = self.connections.get(rule.target_connection_id) if not connection: return rule.stats try: source_objects = self.storage.list_objects_all(bucket_name) source_keys = {obj.key: obj.size for obj in source_objects} s3 = boto3.client( "s3", endpoint_url=connection.endpoint_url, aws_access_key_id=connection.access_key, aws_secret_access_key=connection.secret_key, region_name=connection.region, ) dest_keys = set() bytes_synced = 0 paginator = s3.get_paginator('list_objects_v2') try: for page in paginator.paginate(Bucket=rule.target_bucket): for obj in page.get('Contents', []): dest_keys.add(obj['Key']) if obj['Key'] in source_keys: bytes_synced += obj.get('Size', 0) except ClientError as e: if e.response['Error']['Code'] == 'NoSuchBucket': dest_keys = set() else: raise synced = source_keys.keys() & dest_keys orphaned = dest_keys - source_keys.keys() if rule.mode == REPLICATION_MODE_ALL: pending = source_keys.keys() - dest_keys else: pending = set() rule.stats.objects_synced = len(synced) rule.stats.objects_pending = len(pending) rule.stats.objects_orphaned = len(orphaned) rule.stats.bytes_synced = bytes_synced return rule.stats except (ClientError, StorageError) as e: logger.error(f"Failed to compute sync status for {bucket_name}: {e}") return rule.stats def replicate_existing_objects(self, bucket_name: str) -> None: """Trigger replication for all existing objects in a bucket.""" rule = self.get_rule(bucket_name) if not rule or not rule.enabled: return connection = self.connections.get(rule.target_connection_id) if not connection: logger.warning(f"Cannot replicate existing objects: Connection {rule.target_connection_id} not found") return if not self.check_endpoint_health(connection): logger.warning(f"Cannot replicate existing objects: Endpoint {connection.name} ({connection.endpoint_url}) is not reachable") return try: objects = self.storage.list_objects_all(bucket_name) logger.info(f"Starting replication of {len(objects)} existing objects from {bucket_name}") for obj in objects: self._executor.submit(self._replicate_task, bucket_name, obj.key, rule, connection, "write") except StorageError as e: logger.error(f"Failed to list objects for replication: {e}") def create_remote_bucket(self, connection_id: str, bucket_name: str) -> None: """Create a bucket on the remote connection.""" connection = self.connections.get(connection_id) if not connection: raise ValueError(f"Connection {connection_id} not found") try: s3 = boto3.client( "s3", endpoint_url=connection.endpoint_url, aws_access_key_id=connection.access_key, aws_secret_access_key=connection.secret_key, region_name=connection.region, ) s3.create_bucket(Bucket=bucket_name) except ClientError as e: logger.error(f"Failed to create remote bucket {bucket_name}: {e}") raise def trigger_replication(self, bucket_name: str, object_key: str, action: str = "write") -> None: rule = self.get_rule(bucket_name) if not rule or not rule.enabled: return connection = self.connections.get(rule.target_connection_id) if not connection: logger.warning(f"Replication skipped for {bucket_name}/{object_key}: Connection {rule.target_connection_id} not found") return if not self.check_endpoint_health(connection): logger.warning(f"Replication skipped for {bucket_name}/{object_key}: Endpoint {connection.name} ({connection.endpoint_url}) is not reachable") return self._executor.submit(self._replicate_task, bucket_name, object_key, rule, connection, action) def _replicate_task(self, bucket_name: str, object_key: str, rule: ReplicationRule, conn: RemoteConnection, action: str) -> None: if ".." in object_key or object_key.startswith("/") or object_key.startswith("\\"): logger.error(f"Invalid object key in replication (path traversal attempt): {object_key}") return try: from .storage import ObjectStorage ObjectStorage._sanitize_object_key(object_key) except StorageError as e: logger.error(f"Object key validation failed in replication: {e}") return file_size = 0 try: config = Config( user_agent_extra=REPLICATION_USER_AGENT, connect_timeout=REPLICATION_CONNECT_TIMEOUT, read_timeout=REPLICATION_READ_TIMEOUT, retries={'max_attempts': 2}, signature_version='s3v4', s3={ 'addressing_style': 'path', }, # Disable SDK automatic checksums - they cause SignatureDoesNotMatch errors # with S3-compatible servers that don't support CRC32 checksum headers request_checksum_calculation='when_required', response_checksum_validation='when_required', ) s3 = boto3.client( "s3", endpoint_url=conn.endpoint_url, aws_access_key_id=conn.access_key, aws_secret_access_key=conn.secret_key, region_name=conn.region or 'us-east-1', config=config, ) if action == "delete": try: s3.delete_object(Bucket=rule.target_bucket, Key=object_key) logger.info(f"Replicated DELETE {bucket_name}/{object_key} to {conn.name} ({rule.target_bucket})") self._update_last_sync(bucket_name, object_key) except ClientError as e: logger.error(f"Replication DELETE failed for {bucket_name}/{object_key}: {e}") return try: path = self.storage.get_object_path(bucket_name, object_key) except StorageError: logger.error(f"Source object not found: {bucket_name}/{object_key}") return # Don't replicate metadata - destination server will generate its own # __etag__ and __size__. Replicating them causes signature mismatches when they have None/empty values. content_type, _ = mimetypes.guess_type(path) file_size = path.stat().st_size logger.info(f"Replicating {bucket_name}/{object_key}: Size={file_size}, ContentType={content_type}") def do_put_object() -> None: """Helper to upload object. Reads the file content into memory first to avoid signature calculation issues with certain binary file types (like GIFs) when streaming. Do NOT set ContentLength explicitly - boto3 calculates it from the bytes and setting it manually can cause SignatureDoesNotMatch errors. """ file_content = path.read_bytes() put_kwargs = { "Bucket": rule.target_bucket, "Key": object_key, "Body": file_content, } if content_type: put_kwargs["ContentType"] = content_type s3.put_object(**put_kwargs) try: do_put_object() except (ClientError, S3UploadFailedError) as e: error_code = None if isinstance(e, ClientError): error_code = e.response['Error']['Code'] elif isinstance(e, S3UploadFailedError): if "NoSuchBucket" in str(e): error_code = 'NoSuchBucket' if error_code == 'NoSuchBucket': logger.info(f"Target bucket {rule.target_bucket} not found. Attempting to create it.") bucket_ready = False try: s3.create_bucket(Bucket=rule.target_bucket) bucket_ready = True logger.info(f"Created target bucket {rule.target_bucket}") except ClientError as bucket_err: if bucket_err.response['Error']['Code'] in ('BucketAlreadyExists', 'BucketAlreadyOwnedByYou'): logger.debug(f"Bucket {rule.target_bucket} already exists (created by another thread)") bucket_ready = True else: logger.error(f"Failed to create target bucket {rule.target_bucket}: {bucket_err}") raise e if bucket_ready: do_put_object() else: raise e logger.info(f"Replicated {bucket_name}/{object_key} to {conn.name} ({rule.target_bucket})") self._update_last_sync(bucket_name, object_key) except (ClientError, OSError, ValueError) as e: logger.error(f"Replication failed for {bucket_name}/{object_key}: {e}") except Exception: logger.exception(f"Unexpected error during replication for {bucket_name}/{object_key}")