from datetime import timedelta, datetime
import os

from airflow import DAG
from airflow.operators.dummy_operator import DummyOperator
from airflow.operators.python_operator import PythonOperator

# import pyping

# Default args for DAG.
default_args = {
    'description': 'Determines whether or not an IP address is active',
    'depends_on_past': False,
    'start_date': datetime(2020, 4, 21),
    'catchup': False,
    'email': ['email@email.com'],
    'email_on_failure': True,
    'email_on_retry': False,
    'retry_delay': timedelta(minutes=5),
}

# DAG schedule interval, defined by CRON.
schedule_interval = '0 0 * * *'  # Once a day

# Python def for the ping_ip_task.
def ping_ip():
    ip_address = "000.000.000.00.00"  # My laptop IP
    response = os.system("ping -c 1 " + ip_address)

    if response == 0:
        pingstatus = "Network Active."
    else:
        pingstatus = "Network Error."

    print("\n *** Network status for IP Address=%s is : ***" % ip_address)
    print(pingstatus)

    return pingstatus, response


# Open DAG, give it an ID, schedule, default_args.
with DAG(dag_id='ip_ping', schedule_interval=schedule_interval, default_args=default_args) as dag:
    # Define a Dummy task that does nothing.
    dummy_task = DummyOperator(task_id='dummy_task', retries=3)

    # Define a task that returns the network status of an IP Address.
    ping_ip_task = PythonOperator(task_id='ping_ip', python_callable=ping_ip, retries=1)

    # Declare order of task execution.
    dummy_task >> ping_ip_task