core.py

"""
Carline is designed to be a "pilot" program that will execute a monitor commands in a Docker container.

Workflow:
    1. establish database connection
    2. get meta data from task.json?
        2.1 dictionary -> meta DictField in object
    3. build and save object to database (locking)
    4. run task (wat does this mean? bash? python? how is it passed in?)
    5. clean up environment?
    6. update object in MongoDB
    7. add self to influx
"""

import argparse
import os
from config import MONGODB_DATABASE
from mongoengine import connect
import subprocess as sp
from models import Task
from logging_utils import send_to_influx


def main(c_id):
    MONGODB_IP, INFLUXDB_IP, pbs_job_id = get_env_vars()

    # MONGODB
    try:
        connect(MONGODB_DATABASE, host=MONGODB_IP)
    except Exception as e:
        print(e)
        return

    task_object = Task.objects(c_id=c_id).first()

    if task_object is None:
        print("cannot find c_id {0} in {1}".format(c_id, MONGODB_DATABASE))
        return

    task_object.pbs_job_id = pbs_job_id

    task_object.start()
    run_task(task_object)
    task_object.stop()
    # do something? retries and fault tolerance go here?

    if task_object.influx_measurement is not None:
        send_to_influx(task_object, INFLUXDB_IP, misc=task_object.misc)

    return


def run_task(task):
    try:
        if task.work_dir is not None:
            os.chdir(task.work_dir)
        with open(task.log_file, 'a+') as log_file_handle:

            for cmd in task.cmd_list:
                print(cmd, file=log_file_handle)
                task.set_status(cmd)
                sp.call(cmd, stderr=log_file_handle, stdout=log_file_handle, shell=True)

    except OSError as e:
        print(e)
        task.set_error(e)
        return False
    except Exception as e:
        print(e)
        task.set_error(e)
        return False

    return True


def get_env_vars():
    try:
        mongodb_ip = os.environ['MONGODB_IP']

    except KeyError:
        mongodb_ip = "localhost"

    try:
        influxdb_ip = os.environ['INFLUXDB_IP']
    except KeyError:
        influxdb_ip = "localhost"

    try:
        pbs_job_id = os.environ['PBS_JOBID']
    except KeyError:
        pbs_job_id = "0"

    return mongodb_ip, influxdb_ip, pbs_job_id


if __name__ == '__main__':
    # ARG PARSE
    parser = argparse.ArgumentParser(description="caaarroollline")
    # parser.add_argument('-c', '--task-path', type=str, default='./task.json', help="path to task.json file")
    parser.add_argument('c_id', type=str, help='a uuid to find in MongoDB')

    args = parser.parse_args()
    main(args.c_id)