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"""
This sample "listen to directory". move the new file and print it,
using docker-containers.
The following operators are being used: DockerOperator,
BashOperator & ShortCircuitOperator.
TODO: Review the workflow, change it accordingly to
your environment & enable the code.
"""
from __future__ import annotations
import os
from datetime import datetime
from docker.types import Mount
from airflow import models
from airflow.operators.bash import BashOperator
from airflow.operators.python import ShortCircuitOperator
from airflow.providers.docker.operators.docker import DockerOperator
[docs]ENV_ID = os.environ.get("SYSTEM_TESTS_ENV_ID")
[docs]DAG_ID = "docker_sample_copy_data"
with models.DAG(
DAG_ID,
schedule="@once",
start_date=datetime(2021, 1, 1),
catchup=False,
tags=["example", "docker"],
) as dag:
[docs] locate_file_cmd = """
sleep 10
find {{params.source_location}} -type f -printf "%f\n" | head -1
"""
t_view = BashOperator(
task_id="view_file",
bash_command=locate_file_cmd,
do_xcom_push=True,
params={"source_location": "/your/input_dir/path"},
dag=dag,
)
t_is_data_available = ShortCircuitOperator(
task_id="check_if_data_available",
python_callable=lambda task_output: not task_output == "",
op_kwargs=dict(task_output=t_view.output),
dag=dag,
)
t_move = DockerOperator(
api_version="1.19",
docker_url="tcp://localhost:2375", # replace it with swarm/docker endpoint
image="centos:latest",
network_mode="bridge",
mounts=[
Mount(source="/your/host/input_dir/path", target="/your/input_dir/path", type="bind"),
Mount(source="/your/host/output_dir/path", target="/your/output_dir/path", type="bind"),
],
command=[
"/bin/bash",
"-c",
"/bin/sleep 30; "
"/bin/mv {{ params.source_location }}/" + str(t_view.output) + " {{ params.target_location }};"
"/bin/echo '{{ params.target_location }}/" + f"{t_view.output}';",
],
task_id="move_data",
do_xcom_push=True,
params={"source_location": "/your/input_dir/path", "target_location": "/your/output_dir/path"},
dag=dag,
)
t_print = DockerOperator(
api_version="1.19",
docker_url="tcp://localhost:2375",
image="centos:latest",
mounts=[Mount(source="/your/host/output_dir/path", target="/your/output_dir/path", type="bind")],
command=f"cat {t_move.output}",
task_id="print",
dag=dag,
)
(
# TEST BODY
t_is_data_available
>> t_move
>> t_print
)
from tests.system.utils import get_test_run # noqa: E402
# Needed to run the example DAG with pytest (see: tests/system/README.md#run_via_pytest)
[docs]test_run = get_test_run(dag)
