Task Docker Decorator¶

Python callable wrapped within the @task.docker decorator with args are executed within the docker container.

Parameters¶

The following parameters are supported in Docker Task decorator.

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.

use_dill

Whether to use dill or pickle for serialization

python_command

Python command for executing functions, Default python3

image

Docker image from which to create the container. If image tag is omitted, “latest” will be used.

api_version

Remote API version. Set to auto to automatically detect the server’s version.

container_name

Name of the container. Optional (templated)

cpus

Number of CPUs to assign to the container. This value gets multiplied with 1024.

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.

environment

Environment variables to set in the container. (templated)

private_environment

Private environment variables to set in the container. These are not templated, and hidden from the website.

env_file

Relative path to the .env file with environment variables to set in the container. Overridden by variables in the environment parameter.

force_pull

Pull the docker image on every run. Default is False.

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.

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.

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>" or "container:<id>": Use the network stack of another container specified via <name> or <id>
"host": Use the host network stack. Incompatible with port_bindings
"<network-name>" or "<network-id>": Connects the container to user created network (using docker network create command)

tls_ca_cert

Path to a PEM-encoded certificate authority to secure the docker connection.

tls_client_cert

Path to the PEM-encoded certificate used to authenticate docker client.

tls_client_key

Path to the PEM-encoded key used to authenticate docker client.

tls_verify

Set True to verify the validity of the provided certificate.

tls_hostname

Hostname to match against the docker server certificate or False to disable the check.

tls_ssl_version

Version of SSL to use when communicating with docker daemon.

mount_tmp_dir

Specify whether the temporary directory should be bind-mounted from the host to the container.

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.

user

Default user inside the docker container.

mounts

List of mounts to mount into the container, e.g. ['/host/path:/container/path', '/host/path2:/container/path2:ro'].

working_dir

Working directory to set on the container (equivalent to the -w switch the docker client)

entrypoint

Overwrite the default ENTRYPOINT of the image

xcom_all

Push all the stdout or just the last line. The default is False (last line).

docker_conn_id

ID of the Airflow connection to use

dns

Docker custom DNS servers

dns_search

Docker custom DNS search domain

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

shm_size

Size of /dev/shm in bytes. The size must be greater than 0. If omitted uses system default.

tty

Allocate pseudo-TTY to the container This needs to be set see logs of the Docker container.

hostname

Optional hostname for the container.

privileged

Give extended privileges to this container.

cap_add

Include container capabilities

extra_hosts

Additional hostnames to resolve inside the container, as a mapping of hostname to IP address.

timeout

Default timeout for API calls, in seconds.

device_requests

Expose host resources such as GPUs to the container.

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).

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.

ipc_mode

Set the IPC mode for the container.

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.

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.

ulimits

List of ulimit options to set for the container. Each item should be a docker.types.Ulimit instance.

Usage Example¶

tests/system/docker/example_taskflow_api_docker_virtualenv.py[source]

    @task.docker(image="python:3.9-slim-bookworm", multiple_outputs=True)
    def transform(order_data_dict: dict):
        """
        #### Transform task
        A simple Transform task which takes in the collection of order data and
        computes the total order value.
        """
        total_order_value = 0

        for value in order_data_dict.values():
            total_order_value += value

        return {"total_order_value": total_order_value}