#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied. See the License for the
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# under the License.
"""
Base operator for all operators.
:sphinx-autoapi-skip:
"""
from __future__ import annotations
import abc
import collections.abc
import contextlib
import copy
import functools
import inspect
import logging
import sys
import warnings
from datetime import datetime, timedelta
from functools import total_ordering, wraps
from threading import local
from types import FunctionType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Collection,
Iterable,
NoReturn,
Sequence,
TypeVar,
Union,
cast,
)
import attr
import pendulum
from dateutil.relativedelta import relativedelta
from sqlalchemy import select
from sqlalchemy.orm.exc import NoResultFound
from airflow.configuration import conf
from airflow.exceptions import (
AirflowException,
FailStopDagInvalidTriggerRule,
RemovedInAirflow3Warning,
TaskDeferralError,
TaskDeferred,
)
from airflow.lineage import apply_lineage, prepare_lineage
from airflow.models.abstractoperator import (
DEFAULT_EXECUTOR,
DEFAULT_IGNORE_FIRST_DEPENDS_ON_PAST,
DEFAULT_OWNER,
DEFAULT_POOL_SLOTS,
DEFAULT_PRIORITY_WEIGHT,
DEFAULT_QUEUE,
DEFAULT_RETRIES,
DEFAULT_RETRY_DELAY,
DEFAULT_TASK_EXECUTION_TIMEOUT,
DEFAULT_TRIGGER_RULE,
DEFAULT_WAIT_FOR_PAST_DEPENDS_BEFORE_SKIPPING,
DEFAULT_WEIGHT_RULE,
AbstractOperator,
)
from airflow.models.base import _sentinel
from airflow.models.mappedoperator import OperatorPartial, validate_mapping_kwargs
from airflow.models.param import ParamsDict
from airflow.models.pool import Pool
from airflow.models.taskinstance import TaskInstance, clear_task_instances
from airflow.models.taskmixin import DependencyMixin
from airflow.serialization.enums import DagAttributeTypes
from airflow.task.priority_strategy import PriorityWeightStrategy, validate_and_load_priority_weight_strategy
from airflow.ti_deps.deps.mapped_task_upstream_dep import MappedTaskUpstreamDep
from airflow.ti_deps.deps.not_in_retry_period_dep import NotInRetryPeriodDep
from airflow.ti_deps.deps.not_previously_skipped_dep import NotPreviouslySkippedDep
from airflow.ti_deps.deps.prev_dagrun_dep import PrevDagrunDep
from airflow.ti_deps.deps.trigger_rule_dep import TriggerRuleDep
from airflow.utils import timezone
from airflow.utils.context import Context, context_get_outlet_events
from airflow.utils.decorators import fixup_decorator_warning_stack
from airflow.utils.edgemodifier import EdgeModifier
from airflow.utils.helpers import validate_instance_args, validate_key
from airflow.utils.operator_helpers import ExecutionCallableRunner
from airflow.utils.operator_resources import Resources
from airflow.utils.session import NEW_SESSION, provide_session
from airflow.utils.setup_teardown import SetupTeardownContext
from airflow.utils.trigger_rule import TriggerRule
from airflow.utils.types import NOTSET, AttributeRemoved
from airflow.utils.xcom import XCOM_RETURN_KEY
if TYPE_CHECKING:
from types import ClassMethodDescriptorType
import jinja2 # Slow import.
from sqlalchemy.orm import Session
from airflow.models.abstractoperator import TaskStateChangeCallback
from airflow.models.baseoperatorlink import BaseOperatorLink
from airflow.models.dag import DAG
from airflow.models.operator import Operator
from airflow.models.xcom_arg import XComArg
from airflow.ti_deps.deps.base_ti_dep import BaseTIDep
from airflow.triggers.base import BaseTrigger, StartTriggerArgs
from airflow.utils.task_group import TaskGroup
from airflow.utils.types import ArgNotSet
[docs]ScheduleInterval = Union[str, timedelta, relativedelta]
[docs]TaskPreExecuteHook = Callable[[Context], None]
[docs]TaskPostExecuteHook = Callable[[Context, Any], None]
[docs]T = TypeVar("T", bound=FunctionType)
[docs]logger = logging.getLogger("airflow.models.baseoperator.BaseOperator")
[docs]def parse_retries(retries: Any) -> int | None:
if retries is None:
return 0
elif type(retries) == int: # noqa: E721
return retries
try:
parsed_retries = int(retries)
except (TypeError, ValueError):
raise AirflowException(f"'retries' type must be int, not {type(retries).__name__}")
logger.warning("Implicitly converting 'retries' from %r to int", retries)
return parsed_retries
[docs]def coerce_timedelta(value: float | timedelta, *, key: str) -> timedelta:
if isinstance(value, timedelta):
return value
logger.debug("%s isn't a timedelta object, assuming secs", key)
return timedelta(seconds=value)
[docs]def coerce_resources(resources: dict[str, Any] | None) -> Resources | None:
if resources is None:
return None
return Resources(**resources)
def _get_parent_defaults(dag: DAG | None, task_group: TaskGroup | None) -> tuple[dict, ParamsDict]:
if not dag:
return {}, ParamsDict()
dag_args = copy.copy(dag.default_args)
dag_params = copy.deepcopy(dag.params)
if task_group:
if task_group.default_args and not isinstance(task_group.default_args, collections.abc.Mapping):
raise TypeError("default_args must be a mapping")
dag_args.update(task_group.default_args)
return dag_args, dag_params
[docs]def get_merged_defaults(
dag: DAG | None,
task_group: TaskGroup | None,
task_params: collections.abc.MutableMapping | None,
task_default_args: dict | None,
) -> tuple[dict, ParamsDict]:
args, params = _get_parent_defaults(dag, task_group)
if task_params:
if not isinstance(task_params, collections.abc.Mapping):
raise TypeError("params must be a mapping")
params.update(task_params)
if task_default_args:
if not isinstance(task_default_args, collections.abc.Mapping):
raise TypeError("default_args must be a mapping")
args.update(task_default_args)
with contextlib.suppress(KeyError):
params.update(task_default_args["params"] or {})
return args, params
class _PartialDescriptor:
"""A descriptor that guards against ``.partial`` being called on Task objects."""
class_method: ClassMethodDescriptorType | None = None
def __get__(
self, obj: BaseOperator, cls: type[BaseOperator] | None = None
) -> Callable[..., OperatorPartial]:
# Call this "partial" so it looks nicer in stack traces.
def partial(**kwargs):
raise TypeError("partial can only be called on Operator classes, not Tasks themselves")
if obj is not None:
return partial
return self.class_method.__get__(cls, cls)
_PARTIAL_DEFAULTS: dict[str, Any] = {
"map_index_template": None,
"owner": DEFAULT_OWNER,
"trigger_rule": DEFAULT_TRIGGER_RULE,
"depends_on_past": False,
"ignore_first_depends_on_past": DEFAULT_IGNORE_FIRST_DEPENDS_ON_PAST,
"wait_for_past_depends_before_skipping": DEFAULT_WAIT_FOR_PAST_DEPENDS_BEFORE_SKIPPING,
"wait_for_downstream": False,
"retries": DEFAULT_RETRIES,
"executor": DEFAULT_EXECUTOR,
"queue": DEFAULT_QUEUE,
"pool_slots": DEFAULT_POOL_SLOTS,
"execution_timeout": DEFAULT_TASK_EXECUTION_TIMEOUT,
"retry_delay": DEFAULT_RETRY_DELAY,
"retry_exponential_backoff": False,
"priority_weight": DEFAULT_PRIORITY_WEIGHT,
"weight_rule": DEFAULT_WEIGHT_RULE,
"inlets": [],
"outlets": [],
"allow_nested_operators": True,
}
# This is what handles the actual mapping.
[docs]def partial(
operator_class: type[BaseOperator],
*,
task_id: str,
dag: DAG | None = None,
task_group: TaskGroup | None = None,
start_date: datetime | ArgNotSet = NOTSET,
end_date: datetime | ArgNotSet = NOTSET,
owner: str | ArgNotSet = NOTSET,
email: None | str | Iterable[str] | ArgNotSet = NOTSET,
params: collections.abc.MutableMapping | None = None,
resources: dict[str, Any] | None | ArgNotSet = NOTSET,
trigger_rule: str | ArgNotSet = NOTSET,
depends_on_past: bool | ArgNotSet = NOTSET,
ignore_first_depends_on_past: bool | ArgNotSet = NOTSET,
wait_for_past_depends_before_skipping: bool | ArgNotSet = NOTSET,
wait_for_downstream: bool | ArgNotSet = NOTSET,
retries: int | None | ArgNotSet = NOTSET,
queue: str | ArgNotSet = NOTSET,
pool: str | ArgNotSet = NOTSET,
pool_slots: int | ArgNotSet = NOTSET,
execution_timeout: timedelta | None | ArgNotSet = NOTSET,
max_retry_delay: None | timedelta | float | ArgNotSet = NOTSET,
retry_delay: timedelta | float | ArgNotSet = NOTSET,
retry_exponential_backoff: bool | ArgNotSet = NOTSET,
priority_weight: int | ArgNotSet = NOTSET,
weight_rule: str | PriorityWeightStrategy | ArgNotSet = NOTSET,
sla: timedelta | None | ArgNotSet = NOTSET,
map_index_template: str | None | ArgNotSet = NOTSET,
max_active_tis_per_dag: int | None | ArgNotSet = NOTSET,
max_active_tis_per_dagrun: int | None | ArgNotSet = NOTSET,
on_execute_callback: None | TaskStateChangeCallback | list[TaskStateChangeCallback] | ArgNotSet = NOTSET,
on_failure_callback: None | TaskStateChangeCallback | list[TaskStateChangeCallback] | ArgNotSet = NOTSET,
on_success_callback: None | TaskStateChangeCallback | list[TaskStateChangeCallback] | ArgNotSet = NOTSET,
on_retry_callback: None | TaskStateChangeCallback | list[TaskStateChangeCallback] | ArgNotSet = NOTSET,
on_skipped_callback: None | TaskStateChangeCallback | list[TaskStateChangeCallback] | ArgNotSet = NOTSET,
run_as_user: str | None | ArgNotSet = NOTSET,
executor: str | None | ArgNotSet = NOTSET,
executor_config: dict | None | ArgNotSet = NOTSET,
inlets: Any | None | ArgNotSet = NOTSET,
outlets: Any | None | ArgNotSet = NOTSET,
doc: str | None | ArgNotSet = NOTSET,
doc_md: str | None | ArgNotSet = NOTSET,
doc_json: str | None | ArgNotSet = NOTSET,
doc_yaml: str | None | ArgNotSet = NOTSET,
doc_rst: str | None | ArgNotSet = NOTSET,
task_display_name: str | None | ArgNotSet = NOTSET,
logger_name: str | None | ArgNotSet = NOTSET,
allow_nested_operators: bool = True,
**kwargs,
) -> OperatorPartial:
from airflow.models.dag import DagContext
from airflow.utils.task_group import TaskGroupContext
validate_mapping_kwargs(operator_class, "partial", kwargs)
dag = dag or DagContext.get_current_dag()
if dag:
task_group = task_group or TaskGroupContext.get_current_task_group(dag)
if task_group:
task_id = task_group.child_id(task_id)
# Merge DAG and task group level defaults into user-supplied values.
dag_default_args, partial_params = get_merged_defaults(
dag=dag,
task_group=task_group,
task_params=params,
task_default_args=kwargs.pop("default_args", None),
)
# Create partial_kwargs from args and kwargs
partial_kwargs: dict[str, Any] = {
**kwargs,
"dag": dag,
"task_group": task_group,
"task_id": task_id,
"map_index_template": map_index_template,
"start_date": start_date,
"end_date": end_date,
"owner": owner,
"email": email,
"trigger_rule": trigger_rule,
"depends_on_past": depends_on_past,
"ignore_first_depends_on_past": ignore_first_depends_on_past,
"wait_for_past_depends_before_skipping": wait_for_past_depends_before_skipping,
"wait_for_downstream": wait_for_downstream,
"retries": retries,
"queue": queue,
"pool": pool,
"pool_slots": pool_slots,
"execution_timeout": execution_timeout,
"max_retry_delay": max_retry_delay,
"retry_delay": retry_delay,
"retry_exponential_backoff": retry_exponential_backoff,
"priority_weight": priority_weight,
"weight_rule": weight_rule,
"sla": sla,
"max_active_tis_per_dag": max_active_tis_per_dag,
"max_active_tis_per_dagrun": max_active_tis_per_dagrun,
"on_execute_callback": on_execute_callback,
"on_failure_callback": on_failure_callback,
"on_retry_callback": on_retry_callback,
"on_success_callback": on_success_callback,
"on_skipped_callback": on_skipped_callback,
"run_as_user": run_as_user,
"executor": executor,
"executor_config": executor_config,
"inlets": inlets,
"outlets": outlets,
"resources": resources,
"doc": doc,
"doc_json": doc_json,
"doc_md": doc_md,
"doc_rst": doc_rst,
"doc_yaml": doc_yaml,
"task_display_name": task_display_name,
"logger_name": logger_name,
"allow_nested_operators": allow_nested_operators,
}
# Inject DAG-level default args into args provided to this function.
partial_kwargs.update((k, v) for k, v in dag_default_args.items() if partial_kwargs.get(k) is NOTSET)
# Fill fields not provided by the user with default values.
partial_kwargs = {k: _PARTIAL_DEFAULTS.get(k) if v is NOTSET else v for k, v in partial_kwargs.items()}
# Post-process arguments. Should be kept in sync with _TaskDecorator.expand().
if "task_concurrency" in kwargs: # Reject deprecated option.
raise TypeError("unexpected argument: task_concurrency")
if partial_kwargs["wait_for_downstream"]:
partial_kwargs["depends_on_past"] = True
partial_kwargs["start_date"] = timezone.convert_to_utc(partial_kwargs["start_date"])
partial_kwargs["end_date"] = timezone.convert_to_utc(partial_kwargs["end_date"])
if partial_kwargs["pool"] is None:
partial_kwargs["pool"] = Pool.DEFAULT_POOL_NAME
partial_kwargs["retries"] = parse_retries(partial_kwargs["retries"])
partial_kwargs["retry_delay"] = coerce_timedelta(partial_kwargs["retry_delay"], key="retry_delay")
if partial_kwargs["max_retry_delay"] is not None:
partial_kwargs["max_retry_delay"] = coerce_timedelta(
partial_kwargs["max_retry_delay"],
key="max_retry_delay",
)
partial_kwargs["executor_config"] = partial_kwargs["executor_config"] or {}
partial_kwargs["resources"] = coerce_resources(partial_kwargs["resources"])
return OperatorPartial(
operator_class=operator_class,
kwargs=partial_kwargs,
params=partial_params,
)
[docs]class ExecutorSafeguard:
"""
The ExecutorSafeguard decorator.
Checks if the execute method of an operator isn't manually called outside
the TaskInstance as we want to avoid bad mixing between decorated and
classic operators.
"""
[docs] test_mode = conf.getboolean("core", "unit_test_mode")
_sentinel = local()
_sentinel.callers = {}
@classmethod
[docs] def decorator(cls, func):
@wraps(func)
def wrapper(self, *args, **kwargs):
from airflow.decorators.base import DecoratedOperator
sentinel_key = f"{self.__class__.__name__}__sentinel"
sentinel = kwargs.pop(sentinel_key, None)
if sentinel:
cls._sentinel.callers[sentinel_key] = sentinel
else:
sentinel = cls._sentinel.callers.pop(f"{func.__qualname__.split('.')[0]}__sentinel", None)
if not cls.test_mode and not sentinel == _sentinel and not isinstance(self, DecoratedOperator):
message = f"{self.__class__.__name__}.{func.__name__} cannot be called outside TaskInstance!"
if not self.allow_nested_operators:
raise AirflowException(message)
self.log.warning(message)
return func(self, *args, **kwargs)
return wrapper
# TODO: The following mapping is used to validate that the arguments passed to the BaseOperator are of the
# correct type. This is a temporary solution until we find a more sophisticated method for argument
# validation. One potential method is to use `get_type_hints` from the typing module. However, this is not
# fully compatible with future annotations for Python versions below 3.10. Once we require a minimum Python
# version that supports `get_type_hints` effectively or find a better approach, we can replace this
# manual type-checking method.
[docs]BASEOPERATOR_ARGS_EXPECTED_TYPES = {
"task_id": str,
"email": (str, Iterable),
"email_on_retry": bool,
"email_on_failure": bool,
"retries": int,
"retry_exponential_backoff": bool,
"depends_on_past": bool,
"ignore_first_depends_on_past": bool,
"wait_for_past_depends_before_skipping": bool,
"wait_for_downstream": bool,
"priority_weight": int,
"queue": str,
"pool": str,
"pool_slots": int,
"trigger_rule": str,
"run_as_user": str,
"task_concurrency": int,
"map_index_template": str,
"max_active_tis_per_dag": int,
"max_active_tis_per_dagrun": int,
"executor": str,
"do_xcom_push": bool,
"multiple_outputs": bool,
"doc": str,
"doc_md": str,
"doc_json": str,
"doc_yaml": str,
"doc_rst": str,
"task_display_name": str,
"logger_name": str,
"allow_nested_operators": bool,
}
@total_ordering
[docs]class BaseOperator(AbstractOperator, metaclass=BaseOperatorMeta):
r"""
Abstract base class for all operators.
Since operators create objects that become nodes in the DAG, BaseOperator
contains many recursive methods for DAG crawling behavior. To derive from
this class, you are expected to override the constructor and the 'execute'
method.
Operators derived from this class should perform or trigger certain tasks
synchronously (wait for completion). Example of operators could be an
operator that runs a Pig job (PigOperator), a sensor operator that
waits for a partition to land in Hive (HiveSensorOperator), or one that
moves data from Hive to MySQL (Hive2MySqlOperator). Instances of these
operators (tasks) target specific operations, running specific scripts,
functions or data transfers.
This class is abstract and shouldn't be instantiated. Instantiating a
class derived from this one results in the creation of a task object,
which ultimately becomes a node in DAG objects. Task dependencies should
be set by using the set_upstream and/or set_downstream methods.
:param task_id: a unique, meaningful id for the task
:param owner: the owner of the task. Using a meaningful description
(e.g. user/person/team/role name) to clarify ownership is recommended.
:param email: the 'to' email address(es) used in email alerts. This can be a
single email or multiple ones. Multiple addresses can be specified as a
comma or semicolon separated string or by passing a list of strings.
:param email_on_retry: Indicates whether email alerts should be sent when a
task is retried
:param email_on_failure: Indicates whether email alerts should be sent when
a task failed
:param retries: the number of retries that should be performed before
failing the task
:param retry_delay: delay between retries, can be set as ``timedelta`` or
``float`` seconds, which will be converted into ``timedelta``,
the default is ``timedelta(seconds=300)``.
:param retry_exponential_backoff: allow progressively longer waits between
retries by using exponential backoff algorithm on retry delay (delay
will be converted into seconds)
:param max_retry_delay: maximum delay interval between retries, can be set as
``timedelta`` or ``float`` seconds, which will be converted into ``timedelta``.
:param start_date: The ``start_date`` for the task, determines
the ``execution_date`` for the first task instance. The best practice
is to have the start_date rounded
to your DAG's ``schedule_interval``. Daily jobs have their start_date
some day at 00:00:00, hourly jobs have their start_date at 00:00
of a specific hour. Note that Airflow simply looks at the latest
``execution_date`` and adds the ``schedule_interval`` to determine
the next ``execution_date``. It is also very important
to note that different tasks' dependencies
need to line up in time. If task A depends on task B and their
start_date are offset in a way that their execution_date don't line
up, A's dependencies will never be met. If you are looking to delay
a task, for example running a daily task at 2AM, look into the
``TimeSensor`` and ``TimeDeltaSensor``. We advise against using
dynamic ``start_date`` and recommend using fixed ones. Read the
FAQ entry about start_date for more information.
:param end_date: if specified, the scheduler won't go beyond this date
:param depends_on_past: when set to true, task instances will run
sequentially and only if the previous instance has succeeded or has been skipped.
The task instance for the start_date is allowed to run.
:param wait_for_past_depends_before_skipping: when set to true, if the task instance
should be marked as skipped, and depends_on_past is true, the ti will stay on None state
waiting the task of the previous run
:param wait_for_downstream: when set to true, an instance of task
X will wait for tasks immediately downstream of the previous instance
of task X to finish successfully or be skipped before it runs. This is useful if the
different instances of a task X alter the same asset, and this asset
is used by tasks downstream of task X. Note that depends_on_past
is forced to True wherever wait_for_downstream is used. Also note that
only tasks *immediately* downstream of the previous task instance are waited
for; the statuses of any tasks further downstream are ignored.
:param dag: a reference to the dag the task is attached to (if any)
:param priority_weight: priority weight of this task against other task.
This allows the executor to trigger higher priority tasks before
others when things get backed up. Set priority_weight as a higher
number for more important tasks.
:param weight_rule: weighting method used for the effective total
priority weight of the task. Options are:
``{ downstream | upstream | absolute }`` default is ``downstream``
When set to ``downstream`` the effective weight of the task is the
aggregate sum of all downstream descendants. As a result, upstream
tasks will have higher weight and will be scheduled more aggressively
when using positive weight values. This is useful when you have
multiple dag run instances and desire to have all upstream tasks to
complete for all runs before each dag can continue processing
downstream tasks. When set to ``upstream`` the effective weight is the
aggregate sum of all upstream ancestors. This is the opposite where
downstream tasks have higher weight and will be scheduled more
aggressively when using positive weight values. This is useful when you
have multiple dag run instances and prefer to have each dag complete
before starting upstream tasks of other dags. When set to
``absolute``, the effective weight is the exact ``priority_weight``
specified without additional weighting. You may want to do this when
you know exactly what priority weight each task should have.
Additionally, when set to ``absolute``, there is bonus effect of
significantly speeding up the task creation process as for very large
DAGs. Options can be set as string or using the constants defined in
the static class ``airflow.utils.WeightRule``
|experimental|
Since 2.9.0, Airflow allows to define custom priority weight strategy,
by creating a subclass of
``airflow.task.priority_strategy.PriorityWeightStrategy`` and registering
in a plugin, then providing the class path or the class instance via
``weight_rule`` parameter. The custom priority weight strategy will be
used to calculate the effective total priority weight of the task instance.
:param queue: which queue to target when running this job. Not
all executors implement queue management, the CeleryExecutor
does support targeting specific queues.
:param pool: the slot pool this task should run in, slot pools are a
way to limit concurrency for certain tasks
:param pool_slots: the number of pool slots this task should use (>= 1)
Values less than 1 are not allowed.
:param sla: time by which the job is expected to succeed. Note that
this represents the ``timedelta`` after the period is closed. For
example if you set an SLA of 1 hour, the scheduler would send an email
soon after 1:00AM on the ``2016-01-02`` if the ``2016-01-01`` instance
has not succeeded yet.
The scheduler pays special attention for jobs with an SLA and
sends alert
emails for SLA misses. SLA misses are also recorded in the database
for future reference. All tasks that share the same SLA time
get bundled in a single email, sent soon after that time. SLA
notification are sent once and only once for each task instance.
:param execution_timeout: max time allowed for the execution of
this task instance, if it goes beyond it will raise and fail.
:param on_failure_callback: a function or list of functions to be called when a task instance
of this task fails. a context dictionary is passed as a single
parameter to this function. Context contains references to related
objects to the task instance and is documented under the macros
section of the API.
:param on_execute_callback: much like the ``on_failure_callback`` except
that it is executed right before the task is executed.
:param on_retry_callback: much like the ``on_failure_callback`` except
that it is executed when retries occur.
:param on_success_callback: much like the ``on_failure_callback`` except
that it is executed when the task succeeds.
:param on_skipped_callback: much like the ``on_failure_callback`` except
that it is executed when skipped occur; this callback will be called only if AirflowSkipException get raised.
Explicitly it is NOT called if a task is not started to be executed because of a preceding branching
decision in the DAG or a trigger rule which causes execution to skip so that the task execution
is never scheduled.
:param pre_execute: a function to be called immediately before task
execution, receiving a context dictionary; raising an exception will
prevent the task from being executed.
|experimental|
:param post_execute: a function to be called immediately after task
execution, receiving a context dictionary and task result; raising an
exception will prevent the task from succeeding.
|experimental|
:param trigger_rule: defines the rule by which dependencies are applied
for the task to get triggered. Options are:
``{ all_success | all_failed | all_done | all_skipped | one_success | one_done |
one_failed | none_failed | none_failed_min_one_success | none_skipped | always}``
default is ``all_success``. Options can be set as string or
using the constants defined in the static class
``airflow.utils.TriggerRule``
:param resources: A map of resource parameter names (the argument names of the
Resources constructor) to their values.
:param run_as_user: unix username to impersonate while running the task
:param max_active_tis_per_dag: When set, a task will be able to limit the concurrent
runs across execution_dates.
:param max_active_tis_per_dagrun: When set, a task will be able to limit the concurrent
task instances per DAG run.
:param executor: Which executor to target when running this task. NOT YET SUPPORTED
:param executor_config: Additional task-level configuration parameters that are
interpreted by a specific executor. Parameters are namespaced by the name of
executor.
**Example**: to run this task in a specific docker container through
the KubernetesExecutor ::
MyOperator(..., executor_config={"KubernetesExecutor": {"image": "myCustomDockerImage"}})
:param do_xcom_push: if True, an XCom is pushed containing the Operator's
result
:param multiple_outputs: if True and do_xcom_push is True, pushes multiple XComs, one for each
key in the returned dictionary result. If False and do_xcom_push is True, pushes a single XCom.
:param task_group: The TaskGroup to which the task should belong. This is typically provided when not
using a TaskGroup as a context manager.
:param doc: Add documentation or notes to your Task objects that is visible in
Task Instance details View in the Webserver
:param doc_md: Add documentation (in Markdown format) or notes to your Task objects
that is visible in Task Instance details View in the Webserver
:param doc_rst: Add documentation (in RST format) or notes to your Task objects
that is visible in Task Instance details View in the Webserver
:param doc_json: Add documentation (in JSON format) or notes to your Task objects
that is visible in Task Instance details View in the Webserver
:param doc_yaml: Add documentation (in YAML format) or notes to your Task objects
that is visible in Task Instance details View in the Webserver
:param task_display_name: The display name of the task which appears on the UI.
:param logger_name: Name of the logger used by the Operator to emit logs.
If set to `None` (default), the logger name will fall back to
`airflow.task.operators.{class.__module__}.{class.__name__}` (e.g. SimpleHttpOperator will have
*airflow.task.operators.airflow.providers.http.operators.http.SimpleHttpOperator* as logger).
:param allow_nested_operators: if True, when an operator is executed within another one a warning message
will be logged. If False, then an exception will be raised if the operator is badly used (e.g. nested
within another one). In future releases of Airflow this parameter will be removed and an exception
will always be thrown when operators are nested within each other (default is True).
**Example**: example of a bad operator mixin usage::
@task(provide_context=True)
def say_hello_world(**context):
hello_world_task = BashOperator(
task_id="hello_world_task",
bash_command="python -c \"print('Hello, world!')\"",
dag=dag,
)
hello_world_task.execute(context)
"""
# Implementing Operator.
[docs] template_fields: Sequence[str] = ()
[docs] template_ext: Sequence[str] = ()
[docs] template_fields_renderers: dict[str, str] = {}
# Defines the color in the UI
[docs] ui_fgcolor: str = "#000"
# base list which includes all the attrs that don't need deep copy.
_base_operator_shallow_copy_attrs: tuple[str, ...] = (
"user_defined_macros",
"user_defined_filters",
"params",
)
# each operator should override this class attr for shallow copy attrs.
[docs] shallow_copy_attrs: Sequence[str] = ()
# Defines the operator level extra links
# The _serialized_fields are lazily loaded when get_serialized_fields() method is called
__serialized_fields: frozenset[str] | None = None
[docs] partial: Callable[..., OperatorPartial] = _PartialDescriptor() # type: ignore
_comps = {
"task_id",
"dag_id",
"owner",
"email",
"email_on_retry",
"retry_delay",
"retry_exponential_backoff",
"max_retry_delay",
"start_date",
"end_date",
"depends_on_past",
"wait_for_downstream",
"priority_weight",
"sla",
"execution_timeout",
"on_execute_callback",
"on_failure_callback",
"on_success_callback",
"on_retry_callback",
"on_skipped_callback",
"do_xcom_push",
"multiple_outputs",
"allow_nested_operators",
"executor",
}
# Defines if the operator supports lineage without manual definitions
[docs] supports_lineage = False
# If True then the class constructor was called
__instantiated = False
# List of args as passed to `init()`, after apply_defaults() has been updated. Used to "recreate" the task
# when mapping
__init_kwargs: dict[str, Any]
# Set to True before calling execute method
_lock_for_execution = False
_dag: DAG | None = None
[docs] task_group: TaskGroup | None = None
# subdag parameter is only set for SubDagOperator.
# Setting it to None by default as other Operators do not have that field
[docs] subdag: DAG | None = None
[docs] start_date: pendulum.DateTime | None = None
[docs] end_date: pendulum.DateTime | None = None
# Set to True for an operator instantiated by a mapped operator.
__from_mapped = False
[docs] start_trigger_args: StartTriggerArgs | None = None
[docs] start_from_trigger: bool = False
def __init__(
self,
task_id: str,
owner: str = DEFAULT_OWNER,
email: str | Iterable[str] | None = None,
email_on_retry: bool = conf.getboolean("email", "default_email_on_retry", fallback=True),
email_on_failure: bool = conf.getboolean("email", "default_email_on_failure", fallback=True),
retries: int | None = DEFAULT_RETRIES,
retry_delay: timedelta | float = DEFAULT_RETRY_DELAY,
retry_exponential_backoff: bool = False,
max_retry_delay: timedelta | float | None = None,
start_date: datetime | None = None,
end_date: datetime | None = None,
depends_on_past: bool = False,
ignore_first_depends_on_past: bool = DEFAULT_IGNORE_FIRST_DEPENDS_ON_PAST,
wait_for_past_depends_before_skipping: bool = DEFAULT_WAIT_FOR_PAST_DEPENDS_BEFORE_SKIPPING,
wait_for_downstream: bool = False,
dag: DAG | None = None,
params: collections.abc.MutableMapping | None = None,
default_args: dict | None = None,
priority_weight: int = DEFAULT_PRIORITY_WEIGHT,
weight_rule: str | PriorityWeightStrategy = DEFAULT_WEIGHT_RULE,
queue: str = DEFAULT_QUEUE,
pool: str | None = None,
pool_slots: int = DEFAULT_POOL_SLOTS,
sla: timedelta | None = None,
execution_timeout: timedelta | None = DEFAULT_TASK_EXECUTION_TIMEOUT,
on_execute_callback: None | TaskStateChangeCallback | list[TaskStateChangeCallback] = None,
on_failure_callback: None | TaskStateChangeCallback | list[TaskStateChangeCallback] = None,
on_success_callback: None | TaskStateChangeCallback | list[TaskStateChangeCallback] = None,
on_retry_callback: None | TaskStateChangeCallback | list[TaskStateChangeCallback] = None,
on_skipped_callback: None | TaskStateChangeCallback | list[TaskStateChangeCallback] = None,
pre_execute: TaskPreExecuteHook | None = None,
post_execute: TaskPostExecuteHook | None = None,
trigger_rule: str = DEFAULT_TRIGGER_RULE,
resources: dict[str, Any] | None = None,
run_as_user: str | None = None,
task_concurrency: int | None = None,
map_index_template: str | None = None,
max_active_tis_per_dag: int | None = None,
max_active_tis_per_dagrun: int | None = None,
executor: str | None = None,
executor_config: dict | None = None,
do_xcom_push: bool = True,
multiple_outputs: bool = False,
inlets: Any | None = None,
outlets: Any | None = None,
task_group: TaskGroup | None = None,
doc: str | None = None,
doc_md: str | None = None,
doc_json: str | None = None,
doc_yaml: str | None = None,
doc_rst: str | None = None,
task_display_name: str | None = None,
logger_name: str | None = None,
allow_nested_operators: bool = True,
**kwargs,
):
from airflow.models.dag import DagContext
from airflow.utils.task_group import TaskGroupContext
self.__init_kwargs = {}
super().__init__()
kwargs.pop("_airflow_mapped_validation_only", None)
if kwargs:
if not conf.getboolean("operators", "ALLOW_ILLEGAL_ARGUMENTS"):
raise AirflowException(
f"Invalid arguments were passed to {self.__class__.__name__} (task_id: {task_id}). "
f"Invalid arguments were:\n**kwargs: {kwargs}",
)
warnings.warn(
f"Invalid arguments were passed to {self.__class__.__name__} (task_id: {task_id}). "
"Support for passing such arguments will be dropped in future. "
f"Invalid arguments were:\n**kwargs: {kwargs}",
category=RemovedInAirflow3Warning,
stacklevel=3,
)
validate_key(task_id)
dag = dag or DagContext.get_current_dag()
task_group = task_group or TaskGroupContext.get_current_task_group(dag)
self.task_id = task_group.child_id(task_id) if task_group else task_id
if not self.__from_mapped and task_group:
task_group.add(self)
self.owner = owner
self.email = email
self.email_on_retry = email_on_retry
self.email_on_failure = email_on_failure
if execution_timeout is not None and not isinstance(execution_timeout, timedelta):
raise ValueError(
f"execution_timeout must be timedelta object but passed as type: {type(execution_timeout)}"
)
self.execution_timeout = execution_timeout
self.on_execute_callback = on_execute_callback
self.on_failure_callback = on_failure_callback
self.on_success_callback = on_success_callback
self.on_retry_callback = on_retry_callback
self.on_skipped_callback = on_skipped_callback
self._pre_execute_hook = pre_execute
self._post_execute_hook = post_execute
if start_date and not isinstance(start_date, datetime):
self.log.warning("start_date for %s isn't datetime.datetime", self)
elif start_date:
self.start_date = timezone.convert_to_utc(start_date)
if end_date:
self.end_date = timezone.convert_to_utc(end_date)
self.executor = executor
self.executor_config = executor_config or {}
self.run_as_user = run_as_user
self.retries = parse_retries(retries)
self.queue = queue
self.pool = Pool.DEFAULT_POOL_NAME if pool is None else pool
self.pool_slots = pool_slots
if self.pool_slots < 1:
dag_str = f" in dag {dag.dag_id}" if dag else ""
raise ValueError(f"pool slots for {self.task_id}{dag_str} cannot be less than 1")
self.sla = sla
if trigger_rule == "dummy":
warnings.warn(
"dummy Trigger Rule is deprecated. Please use `TriggerRule.ALWAYS`.",
RemovedInAirflow3Warning,
stacklevel=2,
)
trigger_rule = TriggerRule.ALWAYS
if trigger_rule == "none_failed_or_skipped":
warnings.warn(
"none_failed_or_skipped Trigger Rule is deprecated. "
"Please use `none_failed_min_one_success`.",
RemovedInAirflow3Warning,
stacklevel=2,
)
trigger_rule = TriggerRule.NONE_FAILED_MIN_ONE_SUCCESS
if not TriggerRule.is_valid(trigger_rule):
raise AirflowException(
f"The trigger_rule must be one of {TriggerRule.all_triggers()},"
f"'{dag.dag_id if dag else ''}.{task_id}'; received '{trigger_rule}'."
)
self.trigger_rule: TriggerRule = TriggerRule(trigger_rule)
FailStopDagInvalidTriggerRule.check(dag=dag, trigger_rule=self.trigger_rule)
self.depends_on_past: bool = depends_on_past
self.ignore_first_depends_on_past: bool = ignore_first_depends_on_past
self.wait_for_past_depends_before_skipping: bool = wait_for_past_depends_before_skipping
self.wait_for_downstream: bool = wait_for_downstream
if wait_for_downstream:
self.depends_on_past = True
self.retry_delay = coerce_timedelta(retry_delay, key="retry_delay")
self.retry_exponential_backoff = retry_exponential_backoff
self.max_retry_delay = (
max_retry_delay
if max_retry_delay is None
else coerce_timedelta(max_retry_delay, key="max_retry_delay")
)
# At execution_time this becomes a normal dict
self.params: ParamsDict | dict = ParamsDict(params)
if priority_weight is not None and not isinstance(priority_weight, int):
raise AirflowException(
f"`priority_weight` for task '{self.task_id}' only accepts integers, "
f"received '{type(priority_weight)}'."
)
self.priority_weight = priority_weight
self.weight_rule = validate_and_load_priority_weight_strategy(weight_rule)
self.resources = coerce_resources(resources)
if task_concurrency and not max_active_tis_per_dag:
# TODO: Remove in Airflow 3.0
warnings.warn(
"The 'task_concurrency' parameter is deprecated. Please use 'max_active_tis_per_dag'.",
RemovedInAirflow3Warning,
stacklevel=2,
)
max_active_tis_per_dag = task_concurrency
self.max_active_tis_per_dag: int | None = max_active_tis_per_dag
self.max_active_tis_per_dagrun: int | None = max_active_tis_per_dagrun
self.do_xcom_push: bool = do_xcom_push
self.map_index_template: str | None = map_index_template
self.multiple_outputs: bool = multiple_outputs
self.doc_md = doc_md
self.doc_json = doc_json
self.doc_yaml = doc_yaml
self.doc_rst = doc_rst
self.doc = doc
# Populate the display field only if provided and different from task id
self._task_display_property_value = (
task_display_name if task_display_name and task_display_name != task_id else None
)
self.upstream_task_ids: set[str] = set()
self.downstream_task_ids: set[str] = set()
if dag:
self.dag = dag
self._log_config_logger_name = "airflow.task.operators"
self._logger_name = logger_name
self.allow_nested_operators: bool = allow_nested_operators
# Lineage
self.inlets: list = []
self.outlets: list = []
if inlets:
self.inlets = (
inlets
if isinstance(inlets, list)
else [
inlets,
]
)
if outlets:
self.outlets = (
outlets
if isinstance(outlets, list)
else [
outlets,
]
)
if isinstance(self.template_fields, str):
warnings.warn(
f"The `template_fields` value for {self.task_type} is a string "
"but should be a list or tuple of string. Wrapping it in a list for execution. "
f"Please update {self.task_type} accordingly.",
UserWarning,
stacklevel=2,
)
self.template_fields = [self.template_fields]
self._is_setup = False
self._is_teardown = False
if SetupTeardownContext.active:
SetupTeardownContext.update_context_map(self)
validate_instance_args(self, BASEOPERATOR_ARGS_EXPECTED_TYPES)
[docs] def __eq__(self, other):
if type(self) is type(other):
# Use getattr() instead of __dict__ as __dict__ doesn't return
# correct values for properties.
return all(getattr(self, c, None) == getattr(other, c, None) for c in self._comps)
return False
[docs] def __ne__(self, other):
return not self == other
[docs] def __hash__(self):
hash_components = [type(self)]
for component in self._comps:
val = getattr(self, component, None)
try:
hash(val)
hash_components.append(val)
except TypeError:
hash_components.append(repr(val))
return hash(tuple(hash_components))
# including lineage information
[docs] def __or__(self, other):
"""
Return [This Operator] | [Operator].
The inlets of other will be set to pick up the outlets from this operator.
Other will be set as a downstream task of this operator.
"""
if isinstance(other, BaseOperator):
if not self.outlets and not self.supports_lineage:
raise ValueError("No outlets defined for this operator")
other.add_inlets([self.task_id])
self.set_downstream(other)
else:
raise TypeError(f"Right hand side ({other}) is not an Operator")
return self
# /Composing Operators ---------------------------------------------
[docs] def __gt__(self, other):
"""
Return [Operator] > [Outlet].
If other is an attr annotated object it is set as an outlet of this Operator.
"""
if not isinstance(other, Iterable):
other = [other]
for obj in other:
if not attr.has(obj):
raise TypeError(f"Left hand side ({obj}) is not an outlet")
self.add_outlets(other)
return self
[docs] def __lt__(self, other):
"""
Return [Inlet] > [Operator] or [Operator] < [Inlet].
If other is an attr annotated object it is set as an inlet to this operator.
"""
if not isinstance(other, Iterable):
other = [other]
for obj in other:
if not attr.has(obj):
raise TypeError(f"{obj} cannot be an inlet")
self.add_inlets(other)
return self
[docs] def __setattr__(self, key, value):
super().__setattr__(key, value)
if self.__from_mapped or self._lock_for_execution:
return # Skip any custom behavior for validation and during execute.
if key in self.__init_kwargs:
self.__init_kwargs[key] = value
if self.__instantiated and key in self.template_fields:
# Resolve upstreams set by assigning an XComArg after initializing
# an operator, example:
# op = BashOperator()
# op.bash_command = "sleep 1"
self.set_xcomargs_dependencies()
[docs] def add_inlets(self, inlets: Iterable[Any]):
"""Set inlets to this operator."""
self.inlets.extend(inlets)
[docs] def add_outlets(self, outlets: Iterable[Any]):
"""Define the outlets of this operator."""
self.outlets.extend(outlets)
def get_inlet_defs(self):
"""
Get inlet definitions on this task.
:meta private:
"""
return self.inlets
def get_outlet_defs(self):
"""
Get outlet definitions on this task.
:meta private:
"""
return self.outlets
[docs] def get_dag(self) -> DAG | None:
return self._dag
@property # type: ignore[override]
[docs] def dag(self) -> DAG: # type: ignore[override]
"""Returns the Operator's DAG if set, otherwise raises an error."""
if self._dag:
return self._dag
else:
raise AirflowException(f"Operator {self} has not been assigned to a DAG yet")
@dag.setter
def dag(self, dag: DAG | None):
"""Operators can be assigned to one DAG, one time. Repeat assignments to that same DAG are ok."""
if dag is None:
self._dag = None
return
# if set to removed, then just set and exit
if self._dag.__class__ is AttributeRemoved:
self._dag = dag
return
# if setting to removed, then just set and exit
if dag.__class__ is AttributeRemoved:
self._dag = AttributeRemoved("_dag") # type: ignore[assignment]
return
from airflow.models.dag import DAG
if not isinstance(dag, DAG):
raise TypeError(f"Expected DAG; received {dag.__class__.__name__}")
elif self.has_dag() and self.dag is not dag:
raise AirflowException(f"The DAG assigned to {self} can not be changed.")
if self.__from_mapped:
pass # Don't add to DAG -- the mapped task takes the place.
elif dag.task_dict.get(self.task_id) is not self:
dag.add_task(self)
self._dag = dag
@property
[docs] def task_display_name(self) -> str:
return self._task_display_property_value or self.task_id
[docs] def has_dag(self):
"""Return True if the Operator has been assigned to a DAG."""
return self._dag is not None
[docs] deps: frozenset[BaseTIDep] = frozenset(
{
NotInRetryPeriodDep(),
PrevDagrunDep(),
TriggerRuleDep(),
NotPreviouslySkippedDep(),
MappedTaskUpstreamDep(),
}
)
"""
Returns the set of dependencies for the operator. These differ from execution
context dependencies in that they are specific to tasks and can be
extended/overridden by subclasses.
"""
[docs] def prepare_for_execution(self) -> BaseOperator:
"""Lock task for execution to disable custom action in ``__setattr__`` and return a copy."""
other = copy.copy(self)
other._lock_for_execution = True
return other
[docs] def set_xcomargs_dependencies(self) -> None:
"""
Resolve upstream dependencies of a task.
In this way passing an ``XComArg`` as value for a template field
will result in creating upstream relation between two tasks.
**Example**: ::
with DAG(...):
generate_content = GenerateContentOperator(task_id="generate_content")
send_email = EmailOperator(..., html_content=generate_content.output)
# This is equivalent to
with DAG(...):
generate_content = GenerateContentOperator(task_id="generate_content")
send_email = EmailOperator(..., html_content="{{ task_instance.xcom_pull('generate_content') }}")
generate_content >> send_email
"""
from airflow.models.xcom_arg import XComArg
for field in self.template_fields:
if hasattr(self, field):
arg = getattr(self, field)
XComArg.apply_upstream_relationship(self, arg)
@prepare_lineage
[docs] def pre_execute(self, context: Any):
"""Execute right before self.execute() is called."""
if self._pre_execute_hook is None:
return
ExecutionCallableRunner(
self._pre_execute_hook,
context_get_outlet_events(context),
logger=self.log,
).run(context)
[docs] def execute(self, context: Context) -> Any:
"""
Derive when creating an operator.
Context is the same dictionary used as when rendering jinja templates.
Refer to get_template_context for more context.
"""
raise NotImplementedError()
@apply_lineage
[docs] def post_execute(self, context: Any, result: Any = None):
"""
Execute right after self.execute() is called.
It is passed the execution context and any results returned by the operator.
"""
if self._post_execute_hook is None:
return
ExecutionCallableRunner(
self._post_execute_hook,
context_get_outlet_events(context),
logger=self.log,
).run(context, result)
[docs] def on_kill(self) -> None:
"""
Override this method to clean up subprocesses when a task instance gets killed.
Any use of the threading, subprocess or multiprocessing module within an
operator needs to be cleaned up, or it will leave ghost processes behind.
"""
[docs] def __deepcopy__(self, memo):
# Hack sorting double chained task lists by task_id to avoid hitting
# max_depth on deepcopy operations.
sys.setrecursionlimit(5000) # TODO fix this in a better way
cls = self.__class__
result = cls.__new__(cls)
memo[id(self)] = result
shallow_copy = cls.shallow_copy_attrs + cls._base_operator_shallow_copy_attrs
for k, v in self.__dict__.items():
if k == "_BaseOperator__instantiated":
# Don't set this until the _end_, as it changes behaviour of __setattr__
continue
if k not in shallow_copy:
setattr(result, k, copy.deepcopy(v, memo))
else:
setattr(result, k, copy.copy(v))
result.__instantiated = self.__instantiated
return result
[docs] def __getstate__(self):
state = dict(self.__dict__)
if self._log:
del state["_log"]
return state
[docs] def __setstate__(self, state):
self.__dict__ = state
[docs] def render_template_fields(
self,
context: Context,
jinja_env: jinja2.Environment | None = None,
) -> None:
"""
Template all attributes listed in *self.template_fields*.
This mutates the attributes in-place and is irreversible.
:param context: Context dict with values to apply on content.
:param jinja_env: Jinja's environment to use for rendering.
"""
if not jinja_env:
jinja_env = self.get_template_env()
self._do_render_template_fields(self, self.template_fields, context, jinja_env, set())
@provide_session
[docs] def clear(
self,
start_date: datetime | None = None,
end_date: datetime | None = None,
upstream: bool = False,
downstream: bool = False,
session: Session = NEW_SESSION,
):
"""Clear the state of task instances associated with the task, following the parameters specified."""
qry = select(TaskInstance).where(TaskInstance.dag_id == self.dag_id)
if start_date:
qry = qry.where(TaskInstance.execution_date >= start_date)
if end_date:
qry = qry.where(TaskInstance.execution_date <= end_date)
tasks = [self.task_id]
if upstream:
tasks += [t.task_id for t in self.get_flat_relatives(upstream=True)]
if downstream:
tasks += [t.task_id for t in self.get_flat_relatives(upstream=False)]
qry = qry.where(TaskInstance.task_id.in_(tasks))
results = session.scalars(qry).all()
count = len(results)
clear_task_instances(results, session, dag=self.dag)
session.commit()
return count
@provide_session
[docs] def get_task_instances(
self,
start_date: datetime | None = None,
end_date: datetime | None = None,
session: Session = NEW_SESSION,
) -> list[TaskInstance]:
"""Get task instances related to this task for a specific date range."""
from airflow.models import DagRun
query = (
select(TaskInstance)
.join(TaskInstance.dag_run)
.where(TaskInstance.dag_id == self.dag_id)
.where(TaskInstance.task_id == self.task_id)
)
if start_date:
query = query.where(DagRun.execution_date >= start_date)
if end_date:
query = query.where(DagRun.execution_date <= end_date)
return session.scalars(query.order_by(DagRun.execution_date)).all()
@provide_session
[docs] def run(
self,
start_date: datetime | None = None,
end_date: datetime | None = None,
ignore_first_depends_on_past: bool = True,
wait_for_past_depends_before_skipping: bool = False,
ignore_ti_state: bool = False,
mark_success: bool = False,
test_mode: bool = False,
session: Session = NEW_SESSION,
) -> None:
"""Run a set of task instances for a date range."""
from airflow.models import DagRun
from airflow.utils.types import DagRunType
# Assertions for typing -- we need a dag, for this function, and when we have a DAG we are
# _guaranteed_ to have start_date (else we couldn't have been added to a DAG)
if TYPE_CHECKING:
assert self.start_date
start_date = pendulum.instance(start_date or self.start_date)
end_date = pendulum.instance(end_date or self.end_date or timezone.utcnow())
for info in self.dag.iter_dagrun_infos_between(start_date, end_date, align=False):
ignore_depends_on_past = info.logical_date == start_date and ignore_first_depends_on_past
try:
dag_run = session.scalars(
select(DagRun).where(
DagRun.dag_id == self.dag_id,
DagRun.execution_date == info.logical_date,
)
).one()
ti = TaskInstance(self, run_id=dag_run.run_id)
except NoResultFound:
# This is _mostly_ only used in tests
dr = DagRun(
dag_id=self.dag_id,
run_id=DagRun.generate_run_id(DagRunType.MANUAL, info.logical_date),
run_type=DagRunType.MANUAL,
execution_date=info.logical_date,
data_interval=info.data_interval,
)
ti = TaskInstance(self, run_id=dr.run_id)
session.add(ti)
ti.dag_run = dr
session.add(dr)
session.flush()
session.commit()
ti.run(
mark_success=mark_success,
ignore_depends_on_past=ignore_depends_on_past,
wait_for_past_depends_before_skipping=wait_for_past_depends_before_skipping,
ignore_ti_state=ignore_ti_state,
test_mode=test_mode,
session=session,
)
[docs] def dry_run(self) -> None:
"""Perform dry run for the operator - just render template fields."""
self.log.info("Dry run")
for field in self.template_fields:
try:
content = getattr(self, field)
except AttributeError:
raise AttributeError(
f"{field!r} is configured as a template field "
f"but {self.task_type} does not have this attribute."
)
if content and isinstance(content, str):
self.log.info("Rendering template for %s", field)
self.log.info(content)
[docs] def get_direct_relatives(self, upstream: bool = False) -> Iterable[Operator]:
"""Get list of the direct relatives to the current task, upstream or downstream."""
if upstream:
return self.upstream_list
else:
return self.downstream_list
[docs] def __repr__(self):
return f"<Task({self.task_type}): {self.task_id}>"
@property
[docs] def operator_class(self) -> type[BaseOperator]: # type: ignore[override]
return self.__class__
@property
[docs] def task_type(self) -> str:
"""@property: type of the task."""
return self.__class__.__name__
@property
[docs] def operator_name(self) -> str:
"""@property: use a more friendly display name for the operator, if set."""
try:
return self.custom_operator_name # type: ignore
except AttributeError:
return self.task_type
@property
[docs] def roots(self) -> list[BaseOperator]:
"""Required by DAGNode."""
return [self]
@property
[docs] def leaves(self) -> list[BaseOperator]:
"""Required by DAGNode."""
return [self]
@property
[docs] def output(self) -> XComArg:
"""Returns reference to XCom pushed by current operator."""
from airflow.models.xcom_arg import XComArg
return XComArg(operator=self)
@property
def is_setup(self) -> bool:
"""
Whether the operator is a setup task.
:meta private:
"""
return self._is_setup
@is_setup.setter
def is_setup(self, value: bool) -> None:
"""
Setter for is_setup property.
:meta private:
"""
if self.is_teardown and value:
raise ValueError(f"Cannot mark task '{self.task_id}' as setup; task is already a teardown.")
self._is_setup = value
@property
def is_teardown(self) -> bool:
"""
Whether the operator is a teardown task.
:meta private:
"""
return self._is_teardown
@is_teardown.setter
def is_teardown(self, value: bool) -> None:
"""
Setter for is_teardown property.
:meta private:
"""
if self.is_setup and value:
raise ValueError(f"Cannot mark task '{self.task_id}' as teardown; task is already a setup.")
self._is_teardown = value
@staticmethod
[docs] def xcom_push(
context: Any,
key: str,
value: Any,
execution_date: datetime | None = None,
) -> None:
"""
Make an XCom available for tasks to pull.
:param context: Execution Context Dictionary
:param key: A key for the XCom
:param value: A value for the XCom. The value is pickled and stored
in the database.
:param execution_date: if provided, the XCom will not be visible until
this date. This can be used, for example, to send a message to a
task on a future date without it being immediately visible.
"""
context["ti"].xcom_push(key=key, value=value, execution_date=execution_date)
@staticmethod
@provide_session
[docs] def xcom_pull(
context: Any,
task_ids: str | list[str] | None = None,
dag_id: str | None = None,
key: str = XCOM_RETURN_KEY,
include_prior_dates: bool | None = None,
session: Session = NEW_SESSION,
) -> Any:
"""
Pull XComs that optionally meet certain criteria.
The default value for `key` limits the search to XComs
that were returned by other tasks (as opposed to those that were pushed
manually). To remove this filter, pass key=None (or any desired value).
If a single task_id string is provided, the result is the value of the
most recent matching XCom from that task_id. If multiple task_ids are
provided, a tuple of matching values is returned. None is returned
whenever no matches are found.
:param context: Execution Context Dictionary
:param key: A key for the XCom. If provided, only XComs with matching
keys will be returned. The default key is 'return_value', also
available as a constant XCOM_RETURN_KEY. This key is automatically
given to XComs returned by tasks (as opposed to being pushed
manually). To remove the filter, pass key=None.
:param task_ids: Only XComs from tasks with matching ids will be
pulled. Can pass None to remove the filter.
:param dag_id: If provided, only pulls XComs from this DAG.
If None (default), the DAG of the calling task is used.
:param include_prior_dates: If False, only XComs from the current
execution_date are returned. If True, XComs from previous dates
are returned as well.
"""
return context["ti"].xcom_pull(
key=key,
task_ids=task_ids,
dag_id=dag_id,
include_prior_dates=include_prior_dates,
session=session,
)
@classmethod
[docs] def get_serialized_fields(cls):
"""Stringified DAGs and operators contain exactly these fields."""
if not cls.__serialized_fields:
from airflow.models.dag import DagContext
# make sure the following dummy task is not added to current active
# dag in context, otherwise, it will result in
# `RuntimeError: dictionary changed size during iteration`
# Exception in SerializedDAG.serialize_dag() call.
DagContext.push_context_managed_dag(None)
cls.__serialized_fields = frozenset(
vars(BaseOperator(task_id="test")).keys()
- {
"upstream_task_ids",
"default_args",
"dag",
"_dag",
"label",
"_BaseOperator__instantiated",
"_BaseOperator__init_kwargs",
"_BaseOperator__from_mapped",
"_is_setup",
"_is_teardown",
"_on_failure_fail_dagrun",
}
| { # Class level defaults need to be added to this list
"start_date",
"end_date",
"_task_type",
"_operator_name",
"subdag",
"ui_color",
"ui_fgcolor",
"template_ext",
"template_fields",
"template_fields_renderers",
"params",
"is_setup",
"is_teardown",
"on_failure_fail_dagrun",
"map_index_template",
"start_trigger_args",
"_needs_expansion",
"start_from_trigger",
}
)
DagContext.pop_context_managed_dag()
return cls.__serialized_fields
[docs] def serialize_for_task_group(self) -> tuple[DagAttributeTypes, Any]:
"""Serialize; required by DAGNode."""
return DagAttributeTypes.OP, self.task_id
@property
[docs] def inherits_from_empty_operator(self):
"""Used to determine if an Operator is inherited from EmptyOperator."""
# This looks like `isinstance(self, EmptyOperator) would work, but this also
# needs to cope when `self` is a Serialized instance of a EmptyOperator or one
# of its subclasses (which don't inherit from anything but BaseOperator).
return getattr(self, "_is_empty", False)
[docs] def defer(
self,
*,
trigger: BaseTrigger,
method_name: str,
kwargs: dict[str, Any] | None = None,
timeout: timedelta | None = None,
) -> NoReturn:
"""
Mark this Operator "deferred", suspending its execution until the provided trigger fires an event.
This is achieved by raising a special exception (TaskDeferred)
which is caught in the main _execute_task wrapper. Triggers can send execution back to task or end
the task instance directly. If the trigger will end the task instance itself, ``method_name`` should
be None; otherwise, provide the name of the method that should be used when resuming execution in
the task.
"""
raise TaskDeferred(trigger=trigger, method_name=method_name, kwargs=kwargs, timeout=timeout)
[docs] def resume_execution(self, next_method: str, next_kwargs: dict[str, Any] | None, context: Context):
"""Call this method when a deferred task is resumed."""
# __fail__ is a special signal value for next_method that indicates
# this task was scheduled specifically to fail.
if next_method == "__fail__":
next_kwargs = next_kwargs or {}
traceback = next_kwargs.get("traceback")
if traceback is not None:
self.log.error("Trigger failed:\n%s", "\n".join(traceback))
raise TaskDeferralError(next_kwargs.get("error", "Unknown"))
# Grab the callable off the Operator/Task and add in any kwargs
execute_callable = getattr(self, next_method)
if next_kwargs:
execute_callable = functools.partial(execute_callable, **next_kwargs)
return execute_callable(context)
def unmap(self, resolve: None | dict[str, Any] | tuple[Context, Session]) -> BaseOperator:
"""
Get the "normal" operator from the current operator.
Since a BaseOperator is not mapped to begin with, this simply returns
the original operator.
:meta private:
"""
return self
def expand_start_from_trigger(self, *, context: Context, session: Session) -> bool:
"""
Get the start_from_trigger value of the current abstract operator.
Since a BaseOperator is not mapped to begin with, this simply returns
the original value of start_from_trigger.
:meta private:
"""
return self.start_from_trigger
def expand_start_trigger_args(self, *, context: Context, session: Session) -> StartTriggerArgs | None:
"""
Get the start_trigger_args value of the current abstract operator.
Since a BaseOperator is not mapped to begin with, this simply returns
the original value of start_trigger_args.
:meta private:
"""
return self.start_trigger_args
# TODO: Deprecate for Airflow 3.0
[docs]Chainable = Union[DependencyMixin, Sequence[DependencyMixin]]
[docs]def chain(*tasks: DependencyMixin | Sequence[DependencyMixin]) -> None:
r"""
Given a number of tasks, builds a dependency chain.
This function accepts values of BaseOperator (aka tasks), EdgeModifiers (aka Labels), XComArg, TaskGroups,
or lists containing any mix of these types (or a mix in the same list). If you want to chain between two
lists you must ensure they have the same length.
Using classic operators/sensors:
.. code-block:: python
chain(t1, [t2, t3], [t4, t5], t6)
is equivalent to::
/ -> t2 -> t4 \
t1 -> t6
\ -> t3 -> t5 /
.. code-block:: python
t1.set_downstream(t2)
t1.set_downstream(t3)
t2.set_downstream(t4)
t3.set_downstream(t5)
t4.set_downstream(t6)
t5.set_downstream(t6)
Using task-decorated functions aka XComArgs:
.. code-block:: python
chain(x1(), [x2(), x3()], [x4(), x5()], x6())
is equivalent to::
/ -> x2 -> x4 \
x1 -> x6
\ -> x3 -> x5 /
.. code-block:: python
x1 = x1()
x2 = x2()
x3 = x3()
x4 = x4()
x5 = x5()
x6 = x6()
x1.set_downstream(x2)
x1.set_downstream(x3)
x2.set_downstream(x4)
x3.set_downstream(x5)
x4.set_downstream(x6)
x5.set_downstream(x6)
Using TaskGroups:
.. code-block:: python
chain(t1, task_group1, task_group2, t2)
t1.set_downstream(task_group1)
task_group1.set_downstream(task_group2)
task_group2.set_downstream(t2)
It is also possible to mix between classic operator/sensor, EdgeModifiers, XComArg, and TaskGroups:
.. code-block:: python
chain(t1, [Label("branch one"), Label("branch two")], [x1(), x2()], task_group1, x3())
is equivalent to::
/ "branch one" -> x1 \
t1 -> task_group1 -> x3
\ "branch two" -> x2 /
.. code-block:: python
x1 = x1()
x2 = x2()
x3 = x3()
label1 = Label("branch one")
label2 = Label("branch two")
t1.set_downstream(label1)
label1.set_downstream(x1)
t2.set_downstream(label2)
label2.set_downstream(x2)
x1.set_downstream(task_group1)
x2.set_downstream(task_group1)
task_group1.set_downstream(x3)
# or
x1 = x1()
x2 = x2()
x3 = x3()
t1.set_downstream(x1, edge_modifier=Label("branch one"))
t1.set_downstream(x2, edge_modifier=Label("branch two"))
x1.set_downstream(task_group1)
x2.set_downstream(task_group1)
task_group1.set_downstream(x3)
:param tasks: Individual and/or list of tasks, EdgeModifiers, XComArgs, or TaskGroups to set dependencies
"""
for up_task, down_task in zip(tasks, tasks[1:]):
if isinstance(up_task, DependencyMixin):
up_task.set_downstream(down_task)
continue
if isinstance(down_task, DependencyMixin):
down_task.set_upstream(up_task)
continue
if not isinstance(up_task, Sequence) or not isinstance(down_task, Sequence):
raise TypeError(f"Chain not supported between instances of {type(up_task)} and {type(down_task)}")
up_task_list = up_task
down_task_list = down_task
if len(up_task_list) != len(down_task_list):
raise AirflowException(
f"Chain not supported for different length Iterable. "
f"Got {len(up_task_list)} and {len(down_task_list)}."
)
for up_t, down_t in zip(up_task_list, down_task_list):
up_t.set_downstream(down_t)
[docs]def cross_downstream(
from_tasks: Sequence[DependencyMixin],
to_tasks: DependencyMixin | Sequence[DependencyMixin],
):
r"""
Set downstream dependencies for all tasks in from_tasks to all tasks in to_tasks.
Using classic operators/sensors:
.. code-block:: python
cross_downstream(from_tasks=[t1, t2, t3], to_tasks=[t4, t5, t6])
is equivalent to::
t1 ---> t4
\ /
t2 -X -> t5
/ \
t3 ---> t6
.. code-block:: python
t1.set_downstream(t4)
t1.set_downstream(t5)
t1.set_downstream(t6)
t2.set_downstream(t4)
t2.set_downstream(t5)
t2.set_downstream(t6)
t3.set_downstream(t4)
t3.set_downstream(t5)
t3.set_downstream(t6)
Using task-decorated functions aka XComArgs:
.. code-block:: python
cross_downstream(from_tasks=[x1(), x2(), x3()], to_tasks=[x4(), x5(), x6()])
is equivalent to::
x1 ---> x4
\ /
x2 -X -> x5
/ \
x3 ---> x6
.. code-block:: python
x1 = x1()
x2 = x2()
x3 = x3()
x4 = x4()
x5 = x5()
x6 = x6()
x1.set_downstream(x4)
x1.set_downstream(x5)
x1.set_downstream(x6)
x2.set_downstream(x4)
x2.set_downstream(x5)
x2.set_downstream(x6)
x3.set_downstream(x4)
x3.set_downstream(x5)
x3.set_downstream(x6)
It is also possible to mix between classic operator/sensor and XComArg tasks:
.. code-block:: python
cross_downstream(from_tasks=[t1, x2(), t3], to_tasks=[x1(), t2, x3()])
is equivalent to::
t1 ---> x1
\ /
x2 -X -> t2
/ \
t3 ---> x3
.. code-block:: python
x1 = x1()
x2 = x2()
x3 = x3()
t1.set_downstream(x1)
t1.set_downstream(t2)
t1.set_downstream(x3)
x2.set_downstream(x1)
x2.set_downstream(t2)
x2.set_downstream(x3)
t3.set_downstream(x1)
t3.set_downstream(t2)
t3.set_downstream(x3)
:param from_tasks: List of tasks or XComArgs to start from.
:param to_tasks: List of tasks or XComArgs to set as downstream dependencies.
"""
for task in from_tasks:
task.set_downstream(to_tasks)
[docs]def chain_linear(*elements: DependencyMixin | Sequence[DependencyMixin]):
"""
Simplify task dependency definition.
E.g.: suppose you want precedence like so::
╭─op2─╮ ╭─op4─╮
op1─┤ ├─├─op5─┤─op7
╰-op3─╯ ╰-op6─╯
Then you can accomplish like so::
chain_linear(op1, [op2, op3], [op4, op5, op6], op7)
:param elements: a list of operators / lists of operators
"""
if not elements:
raise ValueError("No tasks provided; nothing to do.")
prev_elem = None
deps_set = False
for curr_elem in elements:
if isinstance(curr_elem, EdgeModifier):
raise ValueError("Labels are not supported by chain_linear")
if prev_elem is not None:
for task in prev_elem:
task >> curr_elem
if not deps_set:
deps_set = True
prev_elem = [curr_elem] if isinstance(curr_elem, DependencyMixin) else curr_elem
if not deps_set:
raise ValueError("No dependencies were set. Did you forget to expand with `*`?")
def __getattr__(name):
"""
PEP-562: Lazy loaded attributes on python modules.
:meta private:
"""
path = __deprecated_imports.get(name)
if not path:
raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
from airflow.utils.module_loading import import_string
warnings.warn(
f"Import `{__name__}.{name}` is deprecated. Please use `{path}.{name}`.",
RemovedInAirflow3Warning,
stacklevel=2,
)
val = import_string(f"{path}.{name}")
# Store for next time
globals()[name] = val
return val
__deprecated_imports = {
"BaseOperatorLink": "airflow.models.baseoperatorlink",
}