# Copyright (C) 2015-2021 The Software Heritage developers
# See the AUTHORS file at the top-level directory of this distribution
# License: GNU General Public License version 3, or any later version
# See top-level LICENSE file for more information
import functools
import logging
import os
import sys
from time import monotonic as _monotonic
import traceback
from typing import Any, Dict, Optional
import urllib.parse
from celery import Celery
from celery.signals import celeryd_after_setup, setup_logging, task_prerun, worker_init
from celery.utils.log import ColorFormatter
from celery.worker.control import Panel
from kombu import Exchange, Queue
import pkg_resources
import requests
from swh.core.config import load_named_config, merge_configs
from swh.core.sentry import init_sentry
from swh.scheduler import CONFIG as SWH_CONFIG
DEFAULT_CONFIG_NAME = "worker"
CONFIG_NAME_ENVVAR = "SWH_WORKER_INSTANCE"
CONFIG_NAME_TEMPLATE = "worker/%s"
DEFAULT_CONFIG = {
"task_broker": ("str", "amqp://guest@localhost//"),
"task_modules": ("list[str]", []),
"task_queues": ("list[str]", []),
"task_soft_time_limit": ("int", 0),
}
logger = logging.getLogger(__name__)
# Celery eats tracebacks in signal callbacks, this decorator catches
# and prints them.
# Also tries to notify Sentry if possible.
def _print_errors(f):
@functools.wraps(f)
def newf(*args, **kwargs):
try:
return f(*args, **kwargs)
except Exception as exc:
traceback.print_exc()
try:
import sentry_sdk
sentry_sdk.capture_exception(exc)
except Exception:
traceback.print_exc()
return newf
[docs]
@setup_logging.connect
@_print_errors
def setup_log_handler(
loglevel=None,
logfile=None,
format=None,
colorize=None,
log_console=None,
log_journal=None,
**kwargs,
):
"""Setup logging according to Software Heritage preferences.
If the environment variable SWH_LOG_CONFIG is provided, this uses the targeted
logging configuration file to configure logging. Otherwise, as before, this uses the
default enclosed coded configuration.
"""
from swh.core.logging import logging_configure
# Retrieve logger configuration yaml filepath from environment variable if any
log_config_path = os.environ.get("SWH_LOG_CONFIG")
if log_config_path is not None:
# Delegate configuration to the log_config_path
logging_configure([], log_config_path)
else:
# Keep the logging config coming from this code block
if loglevel is None:
loglevel = logging.DEBUG
if isinstance(loglevel, str):
loglevel = logging.getLevelName(loglevel)
formatter = logging.Formatter(format)
root_logger = logging.getLogger("")
root_logger.setLevel(logging.INFO)
log_target = os.environ.get("SWH_LOG_TARGET", "console")
if log_target == "console":
log_console = True
elif log_target == "journal":
log_journal = True
# this looks for log levels *higher* than DEBUG
if loglevel <= logging.DEBUG and log_console is None:
log_console = True
if log_console:
color_formatter = ColorFormatter(format) if colorize else formatter
console = logging.StreamHandler()
console.setLevel(logging.DEBUG)
console.setFormatter(color_formatter)
root_logger.addHandler(console)
if log_journal:
try:
from swh.core.logger import JournalHandler
systemd_journal = JournalHandler()
systemd_journal.setLevel(logging.DEBUG)
systemd_journal.setFormatter(formatter)
root_logger.addHandler(systemd_journal)
except ImportError:
root_logger.warning(
"JournalHandler is not available, skipping. "
"Please install swh-core[logging]."
)
# Historical configuration kept as-is
logging_configure(
[
("celery", logging.INFO),
# Silence amqp heartbeat_tick messages
("amqp", loglevel),
# Silence useless "Starting new HTTP connection" messages
("urllib3", logging.WARNING),
# Completely disable azure logspam
("azure.core.pipeline.policies.http_logging_policy", logging.WARNING),
("swh", loglevel),
# get_task_logger makes the swh tasks loggers children of celery.task
("celery.task", loglevel),
]
)
# extra step for amqp
logger = logging.getLogger("amqp")
logger.addFilter(lambda record: not record.msg.startswith("heartbeat_tick"))
return loglevel
[docs]
@celeryd_after_setup.connect
@_print_errors
def setup_queues_and_tasks(sender, instance, **kwargs):
"""Signal called on worker start.
This automatically registers swh.scheduler.task.Task subclasses as
available celery tasks.
This also subscribes the worker to the "implicit" per-task queues defined
for these task classes.
"""
logger.info("Setup Queues & Tasks for %s", sender)
instance.app.conf["worker_name"] = sender
def _init_sentry(sentry_dsn: str, main_package: Optional[str] = None):
try:
from sentry_sdk.integrations.celery import CeleryIntegration
except ImportError:
integrations = []
else:
integrations = [CeleryIntegration()]
init_sentry(sentry_dsn, integrations=integrations, main_package=main_package)
[docs]
@worker_init.connect
@_print_errors
def on_worker_init(*args, **kwargs):
# use a fake sentry DSN to ensure celery integration for sentry is
# properly configured as it must happen in the worker_init signal
# callback, real sentry DSN is then setup in task_prerun signal
# callback (see celery_task_prerun function below)
sentry_dsn = "https://public@sentry.example.org/1"
_init_sentry(sentry_dsn)
if "pytest" in sys.argv[0] or "PYTEST_XDIST_WORKER" in os.environ:
# when pytest collects tests, it breaks the proper configuration
# of the celery integration as a side effect, so we ensure that
# the celery.worker.consumer.build_tracer function gets overridden
# as it should have be
from celery.app import trace
from celery.worker.consumer import consumer
consumer.build_tracer = trace.build_tracer
[docs]
@Panel.register
def monotonic(state):
"""Get the current value for the monotonic clock"""
return {"monotonic": _monotonic()}
[docs]
def route_for_task(name, args, kwargs, options, task=None, **kw):
"""Route tasks according to the task_queue attribute in the task class"""
if name is not None and name.startswith("swh."):
return {"queue": name}
[docs]
def get_queue_stats(app, queue_name):
"""Get the statistics regarding a queue on the broker.
Arguments:
queue_name: name of the queue to check
Returns a dictionary raw from the RabbitMQ management API;
or `None` if the current configuration does not use RabbitMQ.
Interesting keys:
- Consumers (number of consumers for the queue)
- messages (number of messages in queue)
- messages_unacknowledged (number of messages currently being
processed)
Documentation: https://www.rabbitmq.com/management.html#http-api
"""
conn_info = app.connection().info()
if conn_info["transport"] == "memory":
# We're running in a test environment, without RabbitMQ.
return None
url = "http://{hostname}:{port}/api/queues/{vhost}/{queue}".format(
hostname=conn_info["hostname"],
port=conn_info["port"] + 10000,
vhost=urllib.parse.quote(conn_info["virtual_host"], safe=""),
queue=urllib.parse.quote(queue_name, safe=""),
)
credentials = (conn_info["userid"], conn_info["password"])
r = requests.get(url, auth=credentials)
if r.status_code == 404:
return {}
if r.status_code != 200:
raise ValueError(
"Got error %s when reading queue stats: %s" % (r.status_code, r.json())
)
return r.json()
[docs]
def get_queue_length(app, queue_name):
"""Shortcut to get a queue's length"""
stats = get_queue_stats(app, queue_name)
if stats:
return stats.get("messages")
MAX_NUM_TASKS = 10000
[docs]
def get_available_slots(app, queue_name: str, max_length: Optional[int]):
"""Get the number of tasks that can be sent to `queue_name`, when
the queue is limited to `max_length`.
Returns:
The number of available slots in the queue. That result should be positive.
"""
if not max_length:
return MAX_NUM_TASKS
try:
queue_length = get_queue_length(app, queue_name)
# Clamp the return value to MAX_NUM_TASKS
max_val = max(0, min(max_length - queue_length, MAX_NUM_TASKS))
except (ValueError, TypeError):
# Unknown queue length, just schedule all the tasks
max_val = MAX_NUM_TASKS
return max_val
[docs]
def register_task_class(app, name, cls):
"""Register a class-based task under the given name"""
if name in app.tasks:
return
task_instance = cls()
task_instance.name = name
app.register_task(task_instance)
INSTANCE_NAME = os.environ.get(CONFIG_NAME_ENVVAR)
CONFIG_NAME = os.environ.get("SWH_CONFIG_FILENAME")
CONFIG: Dict[str, Any] = {}
if CONFIG_NAME:
# load the celery config from the main config file given as
# SWH_CONFIG_FILENAME environment variable.
# This is expected to have a [celery] section in which we have the
# celery specific configuration.
SWH_CONFIG.clear()
SWH_CONFIG.update(load_named_config(CONFIG_NAME))
CONFIG = SWH_CONFIG.get("celery", {})
if not CONFIG:
# otherwise, back to compat config loading mechanism
if INSTANCE_NAME:
CONFIG_NAME = CONFIG_NAME_TEMPLATE % INSTANCE_NAME
else:
CONFIG_NAME = DEFAULT_CONFIG_NAME
# Load the Celery config
CONFIG = load_named_config(CONFIG_NAME, DEFAULT_CONFIG)
CONFIG.setdefault("task_modules", [])
# load tasks modules declared as plugin entry points
for entrypoint in pkg_resources.iter_entry_points("swh.workers"):
worker_registrer_fn = entrypoint.load()
# The registry function is expected to return a dict which the 'tasks' key
# is a string (or a list of strings) with the name of the python module in
# which celery tasks are defined.
task_modules = worker_registrer_fn().get("task_modules", [])
CONFIG["task_modules"].extend(task_modules)
# Celery Queues
CELERY_QUEUES = [Queue("celery", Exchange("celery"), routing_key="celery")]
CELERY_DEFAULT_CONFIG = dict(
# Timezone configuration: all in UTC
enable_utc=True,
timezone="UTC",
# Imported modules
imports=CONFIG.get("task_modules", []),
# Time (in seconds, or a timedelta object) for when after stored task
# tombstones will be deleted. None means to never expire results.
result_expires=None,
# A string identifying the default serialization method to use. Can
# be json (default), pickle, yaml, msgpack, or any custom
# serialization methods that have been registered with
task_serializer="json",
# Result serialization format
result_serializer="json",
# Acknowledge tasks as soon as they're received. We can do this as we have
# external monitoring to decide if we need to retry tasks.
task_acks_late=False,
# A string identifying the default serialization method to use.
# Can be pickle (default), json, yaml, msgpack or any custom serialization
# methods that have been registered with kombu.serialization.registry
accept_content=["msgpack", "json"],
# If True the task will report its status as “started”
# when the task is executed by a worker.
task_track_started=True,
# Default compression used for task messages. Can be gzip, bzip2
# (if available), or any custom compression schemes registered
# in the Kombu compression registry.
# result_compression='bzip2',
# task_compression='bzip2',
# Disable all rate limits, even if tasks has explicit rate limits set.
# (Disabling rate limits altogether is recommended if you don’t have any
# tasks using them.)
worker_disable_rate_limits=True,
# Task routing
task_routes=route_for_task,
# Allow pool restarts from remote
worker_pool_restarts=True,
# Do not prefetch tasks
worker_prefetch_multiplier=1,
# Send events
worker_send_task_events=True,
# Do not send useless task_sent events
task_send_sent_event=False,
)
[docs]
def build_app(config=None):
config = merge_configs(
{k: v for (k, (_, v)) in DEFAULT_CONFIG.items()}, config or {}
)
config["task_queues"] = CELERY_QUEUES + [
Queue(queue, Exchange(queue), routing_key=queue)
for queue in config.get("task_queues", ())
]
logger.debug("Creating a Celery app with %s", config)
# Instantiate the Celery app
app = Celery(broker=config["task_broker"], task_cls="swh.scheduler.task:SWHTask")
app.add_defaults(CELERY_DEFAULT_CONFIG)
app.add_defaults(config)
return app
app = build_app(CONFIG)
[docs]
@task_prerun.connect
def celery_task_prerun(task_id, task, *args, **kwargs):
task_sentry_settings = CONFIG.get("sentry_settings_for_celery_tasks", {})
task_name_parts = task.name.split(".")
for i in reversed(range(len(task_name_parts) + 1)):
# sentry settings can be defined for task name or package name
object_name = ".".join(task_name_parts[:i])
sentry_settings = task_sentry_settings.get(object_name)
if sentry_settings:
_init_sentry(
sentry_settings.get("dsn"),
main_package=sentry_settings.get("main_package"),
)
break
# XXX for BW compat
Celery.get_queue_length = get_queue_length
