stream.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

# System modules
import json
from time import sleep
import subprocess

# Third-party modules
from astropy.time import Time
from flask import Response, Blueprint

# Custom modules
from utils.url_stuff import api_base_url
from web.server.scheduler import scheduler

web = Blueprint('stream', __name__)

########
# STREAM
########

@web.route('/logfile')
def stream_logfile():
    def inner(today):

        proc = subprocess.Popen(
            [f"tail -f -n30 ./data/log/OARPAF.{today}.log"],
            shell=True,
            stdout=subprocess.PIPE
        )

        try:

            for line in iter(proc.stdout.readline, ''):
                line = line.rstrip().decode()

                if not line:
                    sleep(0.05)
                    yield "event: logfile\ndata: \n\n"
                    continue

                sleep(0.05)
                yield f"event: logfile\ndata: {line}\n\n"

        except GeneratorExit:
            print("qui")
            print("Stop streaming log")
            print("Closing subprocess")
            proc.terminate()
            proc.wait()
            print("Subprocess closed")

    print("Streaming template log...")
    today = Time.now().iso.split()[0]
    return Response(inner(today), mimetype="text/event-stream")