import asyncio
from logging import getLogger
from typing import Any, Callable, Dict, Optional, Type, Union
from warnings import warn
from weakref import WeakSet
from aiormq.abc import ExceptionType
from aiormq.connection import parse_bool, parse_int
from pamqp.common import FieldTable
from yarl import URL
from .abc import (
AbstractChannel, AbstractConnection, AbstractRobustChannel,
AbstractRobustConnection, TimeoutType,
)
from .connection import Connection, make_url
from .exceptions import CONNECTION_EXCEPTIONS
from .robust_channel import RobustChannel
from .tools import CallbackCollection, task
log = getLogger(__name__)
[docs]class RobustConnection(Connection, AbstractRobustConnection):
""" Robust connection """
CHANNEL_REOPEN_PAUSE = 1
CHANNEL_CLASS: Type[RobustChannel] = RobustChannel
KWARGS_TYPES = (
("reconnect_interval", parse_int, "5"),
("fail_fast", parse_bool, "1"),
)
def __init__(
self, url: URL, loop: asyncio.AbstractEventLoop = None, **kwargs: Any
):
super().__init__(url=url, loop=loop, **kwargs)
self.connect_kwargs: Dict[str, Any] = {}
self.reconnect_interval = self.kwargs["reconnect_interval"]
self.fail_fast = self.kwargs["fail_fast"]
self.__channels: WeakSet[AbstractChannel] = WeakSet()
self._connect_lock = asyncio.Lock()
self._is_closed_by_user = False
self.reconnect_callbacks: CallbackCollection = CallbackCollection(self)
@property
def reconnecting(self) -> bool:
return self._connect_lock.locked()
def __repr__(self) -> str:
return '<{0}: "{1}" {2} channels>'.format(
self.__class__.__name__, str(self), len(self.__channels),
)
def _on_connection_close(
self, connection: AbstractConnection, closing: asyncio.Future,
) -> None:
if self.reconnecting:
return
self.connected.clear()
del self.connection
log.debug("Closing AMQP connection %r", connection)
if self.closing.done():
return
log.info(
"Connection to %s closed. Reconnecting after %r seconds.",
self, self.reconnect_interval,
)
self.loop.call_later(
self.reconnect_interval,
self.reconnect,
)
[docs] def add_reconnect_callback(
self, callback: Callable[["RobustConnection"], None],
weak: bool = False,
) -> None:
""" Add callback which will be called after reconnect.
:return: None
"""
warn(
"This method will be removed from future release. "
f"Use {self.__class__.__name__}.reconnect_callbacks.add instead",
DeprecationWarning,
stacklevel=2,
)
self.reconnect_callbacks.add(callback, weak=weak)
async def __cleanup_connection(self, exc: Optional[BaseException]) -> None:
if not hasattr(self, "connection"):
return
await asyncio.gather(
self.connection.close(exc), return_exceptions=True,
)
del self.connection
[docs] async def connect(
self, timeout: TimeoutType = None, **kwargs: Any
) -> None:
if self.is_closed:
raise RuntimeError("{!r} connection closed".format(self))
if kwargs:
# Store connect kwargs for reconnects
self.connect_kwargs = kwargs
if self.reconnecting:
raise RuntimeError(
(
f"Connect method called but connection "
f"{self!r} is reconnecting right now."
), self,
)
async with self._connect_lock:
while not self.closing.done():
try:
await super().connect(
timeout=timeout, **self.connect_kwargs
)
for channel in self.__channels:
await channel.reopen()
self.fail_fast = False
except CONNECTION_EXCEPTIONS as e:
if self.fail_fast:
raise
await self.__cleanup_connection(e)
log.warning(
'Connection attempt to "%s" failed: %s. '
"Reconnecting after %r seconds.",
self,
e,
self.reconnect_interval,
)
except asyncio.CancelledError as e:
await self.__cleanup_connection(e)
raise
else:
self.connected.set()
return
log.info(
"Reconnect attempt failed %s. Retrying after %r seconds.",
self, self.reconnect_interval,
)
await asyncio.sleep(self.reconnect_interval)
@task
async def reconnect(self) -> None:
await self.connect()
self.reconnect_callbacks(self)
[docs] def channel(
self,
channel_number: int = None,
publisher_confirms: bool = True,
on_return_raises: bool = False,
) -> AbstractRobustChannel:
channel: AbstractRobustChannel = super().channel(
channel_number=channel_number,
publisher_confirms=publisher_confirms,
on_return_raises=on_return_raises,
) # type: ignore
self.__channels.add(channel)
self.close_callbacks.add(
lambda c, e: channel.close_callbacks(e),
)
return channel
@property
def is_closed(self) -> bool:
""" Is this connection is closed """
return self._is_closed_by_user or super().is_closed
async def close(
self, exc: Optional[ExceptionType] = asyncio.CancelledError,
) -> None:
if self.is_closed:
return
self._is_closed_by_user = True
if not hasattr(self, "connection"):
return
result = await super().close(exc)
self.close_callbacks(exc)
return result
[docs]async def connect_robust(
url: Union[str, URL] = None,
*,
host: str = "localhost",
port: int = 5672,
login: str = "guest",
password: str = "guest",
virtualhost: str = "/",
ssl: bool = False,
loop: asyncio.AbstractEventLoop = None,
ssl_options: dict = None,
timeout: TimeoutType = None,
client_properties: FieldTable = None,
connection_class: Type[AbstractRobustConnection] = RobustConnection,
**kwargs: Any
) -> AbstractRobustConnection:
""" Make connection to the broker.
Example:
.. code-block:: python
import aio_pika
async def main():
connection = await aio_pika.connect(
"amqp://guest:guest@127.0.0.1/"
)
Connect to localhost with default credentials:
.. code-block:: python
import aio_pika
async def main():
connection = await aio_pika.connect()
.. note::
The available keys for ssl_options parameter are:
* cert_reqs
* certfile
* keyfile
* ssl_version
For an information on what the ssl_options can be set to reference the
`official Python documentation`_ .
Set connection name for RabbitMQ admin panel:
.. code-block:: python
read_connection = await connect(
client_properties={
'connection_name': 'Read connection'
}
)
write_connection = await connect(
client_properties={
'connection_name': 'Write connection'
}
)
.. note:
``client_properties`` argument requires ``aiormq>=2.9``
URL string might be contain ssl parameters e.g.
`amqps://user:pass@host//?ca_certs=ca.pem&certfile=crt.pem&keyfile=key.pem`
:param client_properties: add custom client capability.
:param url:
RFC3986_ formatted broker address. When :class:`None`
will be used keyword arguments.
:param host: hostname of the broker
:param port: broker port 5672 by default
:param login: username string. `'guest'` by default.
:param password: password string. `'guest'` by default.
:param virtualhost: virtualhost parameter. `'/'` by default
:param ssl: use SSL for connection. Should be used with addition kwargs.
:param ssl_options: A dict of values for the SSL connection.
:param timeout: connection timeout in seconds
:param loop:
Event loop (:func:`asyncio.get_event_loop()` when :class:`None`)
:param connection_class: Factory of a new connection
:param kwargs: addition parameters which will be passed to the connection.
:return: :class:`aio_pika.connection.Connection`
.. _RFC3986: https://goo.gl/MzgYAs
.. _official Python documentation: https://goo.gl/pty9xA
"""
connection: AbstractRobustConnection = connection_class(
make_url(
url,
host=host,
port=port,
login=login,
password=password,
virtualhost=virtualhost,
ssl=ssl,
ssl_options=ssl_options,
**kwargs
),
loop=loop,
)
await connection.connect(
timeout=timeout,
client_properties=client_properties,
loop=loop,
)
return connection
__all__ = (
"RobustConnection",
"connect_robust",
)
