创建自定义 @task 装饰器¶
从 Airflow 2.2 开始，可以从提供程序包中向 TaskFlow 接口添加自定义装饰器，并使这些装饰器作为 @task.____ 设计的一部分原生显示。
例如，假设您正在尝试创建一个更简单的机制来将 Python 函数作为“foo”任务运行。创建和注册 @task.foo 的步骤是
创建一个
FooDecoratedOperator在这种情况下，我们假设您有一个现有的
FooOperator，它将 Python 函数作为参数。通过创建一个继承自FooOperator和airflow.decorators.base.DecoratedOperator的FooDecoratedOperator，Airflow 将提供将新类视为 taskflow 原生类所需的大部分功能。您还应该覆盖
custom_operator_name属性以提供任务的自定义名称。例如，apache-airflow-providers-docker提供程序中的_DockerDecoratedOperator将其设置为@task.docker以指示其实现的装饰器名称。创建一个
foo_task函数拥有装饰类后，创建一个像这样的函数，将新的
FooDecoratedOperator转换为 TaskFlow 函数装饰器！from typing import TYPE_CHECKING from airflow.decorators.base import task_decorator_factory if TYPE_CHECKING: from airflow.decorators.base import TaskDecorator def foo_task( python_callable: Callable | None = None, multiple_outputs: bool | None = None, **kwargs, ) -> "TaskDecorator": return task_decorator_factory( python_callable=python_callable, multiple_outputs=multiple_outputs, decorated_operator_class=FooDecoratedOperator, **kwargs, )
在提供程序的 get_provider_info 中注册新的装饰器
最后，将键值对
task-decorators添加到从提供程序入口点返回的字典中，如 如何创建自己的提供程序 中所述。这应该是一个列表，其中每个项目都包含name和class-name键。当 Airflow 启动时，ProviderManager类将自动导入此值，并且task.foo将作为新的装饰器工作！def get_provider_info(): return { "package-name": "foo-provider-airflow", "name": "Foo", "task-decorators": [ { "name": "foo", # "Import path" and function name of the `foo_task` "class-name": "name.of.python.package.foo_task", } ], # ... }
请注意，
name必须是有效的 Python 标识符。
（可选）添加 IDE 自动补全支持¶
注意
本节主要适用于 apache-airflow 管理的提供程序。我们尚未决定是否允许第三方提供程序以这种方式注册自动补全。
不管好坏，Python IDE 都无法自动补全动态生成的方法（请参阅 JetBrain 关于此主题的文章）。
为了解决这个问题，提供了一个类型存根 airflow/decorators/__init__.pyi 来静态声明每个任务装饰器的类型签名。新添加的任务装饰器应像这样声明其签名存根
airflow/decorators/__init__.pyi
def docker(
self,
*,
multiple_outputs: bool | None = None,
use_dill: bool = False, # Added by _DockerDecoratedOperator.
python_command: str = "python3",
# 'command', 'retrieve_output', and 'retrieve_output_path' are filled by
# _DockerDecoratedOperator.
image: str,
api_version: str | None = None,
container_name: str | None = None,
cpus: float = 1.0,
docker_url: str | None = None,
environment: dict[str, str] | None = None,
private_environment: dict[str, str] | None = None,
env_file: str | None = None,
force_pull: bool = False,
mem_limit: float | str | None = None,
host_tmp_dir: str | None = None,
network_mode: str | None = None,
tls_ca_cert: str | None = None,
tls_client_cert: str | None = None,
tls_client_key: str | None = None,
tls_verify: bool = True,
tls_hostname: str | bool | None = None,
tls_ssl_version: str | None = None,
mount_tmp_dir: bool = True,
tmp_dir: str = "/tmp/airflow",
user: str | int | None = None,
mounts: list[str] | None = None,
entrypoint: str | list[str] | None = None,
working_dir: str | None = None,
xcom_all: bool = False,
docker_conn_id: str | None = None,
dns: list[str] | None = None,
dns_search: list[str] | None = None,
auto_remove: Literal["never", "success", "force"] = "never",
shm_size: int | None = None,
tty: bool = False,
hostname: str | None = None,
privileged: bool = False,
cap_add: str | None = None,
extra_hosts: dict[str, str] | None = None,
timeout: int = 60,
device_requests: list[dict] | None = None,
log_opts_max_size: str | None = None,
log_opts_max_file: str | None = None,
ipc_mode: str | None = None,
skip_on_exit_code: int | Container[int] | None = None,
port_bindings: dict | None = None,
ulimits: list[dict] | None = None,
**kwargs,
) -> TaskDecorator:
"""Create a decorator to convert the decorated callable to a Docker task.
:param multiple_outputs: If set, function return value will be unrolled to multiple XCom values.
Dict will unroll to XCom values with keys as XCom keys. Defaults to False.
:param use_dill: Whether to use dill or pickle for serialization
:param python_command: Python command for executing functions, Default: python3
:param image: Docker image from which to create the container.
If image tag is omitted, "latest" will be used.
:param api_version: Remote API version. Set to ``auto`` to automatically
detect the server's version.
:param container_name: Name of the container. Optional (templated)
:param cpus: Number of CPUs to assign to the container.
This value gets multiplied with 1024. See
https://docs.docker.net.cn/engine/reference/run/#cpu-share-constraint
:param docker_url: URL of the host running the docker daemon.
Default is the value of the ``DOCKER_HOST`` environment variable or unix://var/run/docker.sock
if it is unset.
:param environment: Environment variables to set in the container. (templated)
:param private_environment: Private environment variables to set in the container.
These are not templated, and hidden from the website.
:param env_file: Relative path to the ``.env`` file with environment variables to set in the container.
Overridden by variables in the environment parameter.
:param force_pull: Pull the docker image on every run. Default is False.
:param mem_limit: Maximum amount of memory the container can use.
Either a float value, which represents the limit in bytes,
or a string like ``128m`` or ``1g``.
:param host_tmp_dir: Specify the location of the temporary directory on the host which will
be mapped to tmp_dir. If not provided defaults to using the standard system temp directory.
:param network_mode: Network mode for the container. It can be one of the following:
- ``"bridge"``: Create new network stack for the container with default docker bridge network
- ``"none"``: No networking for this container
- ``"container:<name|id>"``: Use the network stack of another container specified via <name|id>
- ``"host"``: Use the host network stack. Incompatible with `port_bindings`
- ``"<network-name>|<network-id>"``: Connects the container to user created network
(using ``docker network create`` command)
:param tls_ca_cert: Path to a PEM-encoded certificate authority
to secure the docker connection.
:param tls_client_cert: Path to the PEM-encoded certificate
used to authenticate docker client.
:param tls_client_key: Path to the PEM-encoded key used to authenticate docker client.
:param tls_verify: Set ``True`` to verify the validity of the provided certificate.
:param tls_hostname: Hostname to match against
the docker server certificate or False to disable the check.
:param tls_ssl_version: Version of SSL to use when communicating with docker daemon.
:param mount_tmp_dir: Specify whether the temporary directory should be bind-mounted
from the host to the container. Defaults to True
:param tmp_dir: Mount point inside the container to
a temporary directory created on the host by the operator.
The path is also made available via the environment variable
``AIRFLOW_TMP_DIR`` inside the container.
:param user: Default user inside the docker container.
:param mounts: List of mounts to mount into the container, e.g.
``['/host/path:/container/path', '/host/path2:/container/path2:ro']``.
:param entrypoint: Overwrite the default ENTRYPOINT of the image
:param working_dir: Working directory to
set on the container (equivalent to the -w switch the docker client)
:param xcom_all: Push all the stdout or just the last line.
The default is False (last line).
:param docker_conn_id: The :ref:`Docker connection id <howto/connection:docker>`
:param dns: Docker custom DNS servers
:param dns_search: Docker custom DNS search domain
:param auto_remove: Enable removal of the container when the container's process exits. Possible values:
- ``never``: (default) do not remove container
- ``success``: remove on success
- ``force``: always remove container
:param shm_size: Size of ``/dev/shm`` in bytes. The size must be
greater than 0. If omitted uses system default.
:param tty: Allocate pseudo-TTY to the container
This needs to be set see logs of the Docker container.
:param hostname: Optional hostname for the container.
:param privileged: Give extended privileges to this container.
:param cap_add: Include container capabilities
:param extra_hosts: Additional hostnames to resolve inside the container,
as a mapping of hostname to IP address.
:param device_requests: Expose host resources such as GPUs to the container.
:param log_opts_max_size: The maximum size of the log before it is rolled.
A positive integer plus a modifier representing the unit of measure (k, m, or g).
Eg: 10m or 1g Defaults to -1 (unlimited).
:param log_opts_max_file: The maximum number of log files that can be present.
If rolling the logs creates excess files, the oldest file is removed.
Only effective when max-size is also set. A positive integer. Defaults to 1.
:param ipc_mode: Set the IPC mode for the container.
:param skip_on_exit_code: If task exits with this exit code, leave the task
in ``skipped`` state (default: None). If set to ``None``, any non-zero
exit code will be treated as a failure.
:param port_bindings: Publish a container's port(s) to the host. It is a
dictionary of value where the key indicates the port to open inside the container
and value indicates the host port that binds to the container port.
Incompatible with ``"host"`` in ``network_mode``.
:param ulimits: List of ulimit options to set for the container. Each item should
be a :py:class:`docker.types.Ulimit` instance.
"""
签名应该只允许关键字参数，包括默认自动提供的名为 multiple_outputs 的参数。所有其他参数都应直接从真实的 FooOperator 复制，我们建议添加注释以解释哪些参数由 FooDecoratedOperator 自动填充，因此不包括在内。
如果新装饰器可以在没有参数的情况下使用（例如 @task.python 而不是 @task.python()），则还应该在“真实”定义之后立即添加一个接受单个可调用对象的重载，以便 mypy 可以将该函数识别为“裸装饰器”
airflow/decorators/__init__.pyi
@overload
def python(self, python_callable: Callable[FParams, FReturn]) -> Task[FParams, FReturn]: ...
一旦更改被合并并且下一个 Airflow（次要或补丁）版本发布，用户将能够在 IDE 自动补全中看到您的装饰器。此自动补全将根据用户安装的提供程序版本而改变。
请注意，此步骤不是创建工作装饰器所必需的，但确实为提供程序的用户创造了更好的体验。