Source code for airflow.executors.executor_loader

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"""All executors."""
import logging
from contextlib import suppress
from enum import Enum, unique
from typing import TYPE_CHECKING, Optional, Tuple, Type

from airflow.exceptions import AirflowConfigException
from airflow.executors.executor_constants import (
from airflow.utils.module_loading import import_string

[docs]log = logging.getLogger(__name__)
if TYPE_CHECKING: from airflow.executors.base_executor import BaseExecutor @unique
[docs]class ConnectorSource(Enum): """Enum of supported executor import sources."""
[docs] CORE = "core"
[docs] PLUGIN = "plugin"
[docs] CUSTOM_PATH = "custom path"
[docs]class ExecutorLoader: """Keeps constants for all the currently available executors.""" _default_executor: Optional["BaseExecutor"] = None
[docs] executors = { LOCAL_EXECUTOR: 'airflow.executors.local_executor.LocalExecutor', LOCAL_KUBERNETES_EXECUTOR: 'airflow.executors.local_kubernetes_executor.LocalKubernetesExecutor', SEQUENTIAL_EXECUTOR: 'airflow.executors.sequential_executor.SequentialExecutor', CELERY_EXECUTOR: 'airflow.executors.celery_executor.CeleryExecutor', CELERY_KUBERNETES_EXECUTOR: 'airflow.executors.celery_kubernetes_executor.CeleryKubernetesExecutor', DASK_EXECUTOR: 'airflow.executors.dask_executor.DaskExecutor', KUBERNETES_EXECUTOR: 'airflow.executors.kubernetes_executor.KubernetesExecutor', DEBUG_EXECUTOR: 'airflow.executors.debug_executor.DebugExecutor',
} @classmethod
[docs] def get_default_executor(cls) -> "BaseExecutor": """Creates a new instance of the configured executor if none exists and returns it""" if cls._default_executor is not None: return cls._default_executor from airflow.configuration import conf executor_name = conf.get('core', 'EXECUTOR') cls._default_executor = cls.load_executor(executor_name) return cls._default_executor
[docs] def load_executor(cls, executor_name: str) -> "BaseExecutor": """ Loads the executor. This supports the following formats: * by executor name for core executor * by ``{plugin_name}.{class_name}`` for executor from plugins * by import path. :return: an instance of executor class via executor_name """ if executor_name == CELERY_KUBERNETES_EXECUTOR: return cls.__load_celery_kubernetes_executor() elif executor_name == LOCAL_KUBERNETES_EXECUTOR: return cls.__load_local_kubernetes_executor() try: executor_cls, import_source = cls.import_executor_cls(executor_name) log.debug("Loading executor %s from %s", executor_name, import_source.value) except ImportError as e: log.error(e) raise AirflowConfigException( f'The module/attribute could not be loaded. Please check "executor" key in "core" section. ' f'Current value: "{executor_name}".' )"Loaded executor: %s", executor_name) return executor_cls()
[docs] def import_executor_cls(cls, executor_name: str) -> Tuple[Type["BaseExecutor"], ConnectorSource]: """ Imports the executor class. Supports the same formats as ExecutorLoader.load_executor. :return: executor class via executor_name and executor import source """ if executor_name in cls.executors: return import_string(cls.executors[executor_name]), ConnectorSource.CORE if executor_name.count(".") == 1: log.debug( "The executor name looks like the plugin path (executor_name=%s). Trying to import a " "executor from a plugin", executor_name, ) with suppress(ImportError, AttributeError): # Load plugins here for executors as at that time the plugins might not have been # initialized yet from airflow import plugins_manager plugins_manager.integrate_executor_plugins() return import_string(f"airflow.executors.{executor_name}"), ConnectorSource.PLUGIN return import_string(executor_name), ConnectorSource.CUSTOM_PATH
@classmethod def __load_celery_kubernetes_executor(cls) -> "BaseExecutor": """:return: an instance of CeleryKubernetesExecutor""" celery_executor = import_string(cls.executors[CELERY_EXECUTOR])() kubernetes_executor = import_string(cls.executors[KUBERNETES_EXECUTOR])() celery_kubernetes_executor_cls = import_string(cls.executors[CELERY_KUBERNETES_EXECUTOR]) return celery_kubernetes_executor_cls(celery_executor, kubernetes_executor) @classmethod def __load_local_kubernetes_executor(cls) -> "BaseExecutor": """:return: an instance of LocalKubernetesExecutor""" local_executor = import_string(cls.executors[LOCAL_EXECUTOR])() kubernetes_executor = import_string(cls.executors[KUBERNETES_EXECUTOR])() local_kubernetes_executor_cls = import_string(cls.executors[LOCAL_KUBERNETES_EXECUTOR]) return local_kubernetes_executor_cls(local_executor, kubernetes_executor)

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