import asyncio
import concurrent.futures
import contextlib
import json
import logging
import os
import time
import uuid
from typing import Generator
from defence360agent.api.server import (
APIError,
APIErrorTooManyRequests,
APITokenError,
send_message,
)
from defence360agent.contracts import license
from defence360agent.contracts.config import Core
from defence360agent.contracts.messages import (
Message,
MessageList,
MessageType,
)
from defence360agent.contracts.plugins import MessageSink, expect
from defence360agent.internals.persistent_message import (
PersistentMessagesQueue,
)
from defence360agent.utils import recurring_check, Scope
from defence360agent.utils.json import ServerJSONEncoder
logger = logging.getLogger(__name__)
class SendToServerClient:
"""Send messages to server.
* process Reportable messages;
* add them to a pending messages list;
* send all pending messages to server when list is full (contains
_PENDING_MESSAGES_LIMIT items or more);
* send all pending messages on plugin shutdown."""
_PENDING_MESSAGES_LIMIT = int(
os.environ.get("IMUNIFYAV_MESSAGES_COUNT_TO_SEND", 20)
)
_SEND_MESSAGE_RECURRING_TIME = 60 * 5 # 5 minutes
# 50 second because it should be less than DefaultTimeoutStopSec
_SHUTDOWN_SEND_TIMEOUT = 50
async def create_sink(self, loop: asyncio.AbstractEventLoop):
self._loop = loop
self._pending = PersistentMessagesQueue()
self._try_send = asyncio.Event()
self._lock = asyncio.Lock()
self._sender_task = loop.create_task(self._send())
self._invoke_send_message_task = loop.create_task(
self._invoke_send_message()
)
async def shutdown(self) -> None:
"""
When shutdown begins it gives 50 seconds
to send _pending messages to the server
(after 60 seconds process will bi killed by systemd)
If stop() isn't done in 50 second it terminates
process of sending messages and logs error
"""
try:
await asyncio.wait_for(self.stop(), self._SHUTDOWN_SEND_TIMEOUT)
except asyncio.TimeoutError:
# Used logger.error to notify sentry
logger.error(
"Timeout (%ds) sending messages to server on shutdown.",
self._SHUTDOWN_SEND_TIMEOUT,
)
if not self._sender_task.cancelled():
self._sender_task.cancel()
with contextlib.suppress(asyncio.CancelledError):
await self._sender_task
if self._pending.buffer_size > 0:
logger.warning(
"Save %s messages to persistent storage",
self._pending.buffer_size,
)
self._pending.push_buffer_to_storage()
logger.warning("Stored queue %r", self._pending.qsize())
async def stop(self):
"""
Stop sending.
1. wait for the lock being available
i.e., while _sender_task finishes the current round
of sending message (if it takes too long, then
the timeout in shutdown() is triggered
2. once the sending round complete (we got the lock),
cancel the next iteration of the _sender_task (it exits)
3. send _pending messages (again, if it takes too long,
the timeout in shutdown() is triggered
and the coroutine is cancelled
That method makes sure that the coroutine
that was started in it has ended.
It excludes a situation when:
-> The result of a coroutine that started
BEFORE shutdown() is started.
-> And the process of sending messages
from _pending is interrupted because of it
"""
# The _lock allows you to be sure that the _send_pending_messages
# coroutine is not running and _pending is not being used
logger.info("SendToServer.stop cancel _invoke_send_message_task")
self._invoke_send_message_task.cancel()
with contextlib.suppress(asyncio.CancelledError):
await self._invoke_send_message_task
logger.info("SendToServer.stop wait lock")
async with self._lock:
# Cancel _sender_task. The lock ensures that the coroutine
# is not in its critical part
logger.info("SendToServer.stop lock acquired, cancel _sender_task")
self._sender_task.cancel()
with contextlib.suppress(asyncio.CancelledError):
await self._sender_task
# send messages that are in _pending at the time of agent shutdown
await self._send_pending_messages()
@staticmethod
def _set_api_attrs(api):
api.set_product_name(license.LicenseCLN.get_product_name())
api.set_server_id(license.LicenseCLN.get_server_id())
api.set_license(license.LicenseCLN.get_token())
return api
@contextlib.contextmanager
def _get_api(self) -> Generator[send_message.SendMessageAPI, None, None]:
base_url = os.environ.get("IMUNIFYAV_API_BASE")
# we send messages sequentially, so max_workers=1
with concurrent.futures.ThreadPoolExecutor(max_workers=2) as executor:
api = send_message.SendMessageAPI(
Core.VERSION, base_url, executor=executor
)
yield self._set_api_attrs(api)
@expect(MessageType.Reportable)
async def send_to_server(self, message: Message) -> None:
# add message handling time if it does not exist, so that
# the server does not depend on the time it was received
if "timestamp" not in message:
message["timestamp"] = time.time()
if "message_id" not in message:
message["message_id"] = uuid.uuid4().hex
self._pending.put(self._encode_data_to_put_in_queue(message))
self._try_send.set()
@recurring_check(_SEND_MESSAGE_RECURRING_TIME)
async def _invoke_send_message(self):
self._try_send.set()
@recurring_check(0)
async def _send(self):
await self._try_send.wait()
self._try_send.clear()
if self._pending.qsize() >= self._PENDING_MESSAGES_LIMIT:
# The _lock protects critical part of _send method
logger.info("SendToServer._send wait lock")
need_to_cancel = None
async with self._lock:
logger.info("SendToServer._send lock acquired")
try:
await self._send_pending_messages()
except asyncio.CancelledError as e:
logger.info("SendToServer._send cancelled unlocking")
need_to_cancel = e
logger.info("SendToServer._send lock released")
if need_to_cancel:
raise need_to_cancel
def _encode_data_to_put_in_queue(self, data: Message) -> bytes:
msg = json.dumps(data, cls=ServerJSONEncoder) + "\n"
return msg.encode()
def _decode_message(self, message: bytes) -> Message:
data = json.loads(message)
if data.get("list"):
return MessageList(data.get("list"))
return Message(data)
async def _send_pending_messages(self) -> None:
messages = self._pending.pop_all()
logger.info("Sending %s messages", len(messages))
with self._get_api() as api:
if api.server_id is not None:
stop_attempt = False
for timestamp, message_bytes in messages:
if stop_attempt:
self._pending.put(message_bytes, timestamp=timestamp)
continue
try:
message = self._decode_message(message_bytes)
await api.send_message(message)
logger.info(
"message sent %s",
{
"method": message.get("method"),
"message_id": message.get("message_id"),
},
)
except APIErrorTooManyRequests as exc:
logger.warning(
"Too many requests on send message %s to"
" server: %s",
{
"method": message.get("method"),
"message_id": message.get("message_id"),
},
exc,
)
message["api_retries_count"] = (
message.get("api_retries_count", 0) + 1
)
self._pending.put(
self._encode_data_to_put_in_queue(message),
timestamp=timestamp,
)
stop_attempt = True
except APITokenError as exc:
logger.warning(
"Token error on send message %s to server: %s",
{
"method": message.get("method"),
"message_id": message.get("message_id"),
},
exc,
)
message["api_retries_count"] = (
message.get("api_retries_count", 0) + 1
)
self._pending.put(
self._encode_data_to_put_in_queue(message),
timestamp=timestamp,
)
stop_attempt = True
except APIError as exc:
logger.warning(
"Failed to send message %s to server: %s",
{
"method": message.get("method"),
"message_id": message.get("message_id"),
},
exc,
)
message["api_retries_count"] = (
message.get("api_retries_count", 0) + 1
)
self._pending.put(
self._encode_data_to_put_in_queue(message),
timestamp=timestamp,
)
logger.info("Unsuccessful to send %s messages", self._pending.qsize())
class SendToServer(SendToServerClient, MessageSink):
SCOPE = Scope.AV
SHUTDOWN_PRIORITY = 900 # Shutdown late, after Accumulate has flushed
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