text: #
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  # 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
  # specific language governing permissions and limitations
  # under the License.
  
  """
  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.
  """
  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
  
  ENV_ID = os.environ.get("SYSTEM_TESTS_ENV_ID")
  DAG_ID = 'docker_sample_copy_data'
  
  with models.DAG(
      DAG_ID,
      schedule_interval="@once",
      start_date=datetime(2021, 1, 1),
      catchup=False,
      tags=["example", "docker"],
  ) as dag:
  
      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)
  test_run = get_test_run(dag)
  