Add a cron job using apscheduler in Flask (flask factory)

Question

G'day mates. I'm trying to add a cron job to call my cron_job_notes_recall function periodically but Flask gives an error:

No application found. Either work inside a view function or push an application context. See http://flask-sqlalchemy.pocoo.org/contexts/.

Ok, I followed the Flask Factory approach and everything is being initialized in init.py hence I decided to start my job here. I am pretty sure that the function works properly because I put it into a function as a route and call it. I suppose the problem might be caused by my database (?). The function simply makes a query to DB which is initialized above afterward send an e-mail if the query returned something. Do You have any idea where my cron job should be initialized ?

init.py

# Globally accessible libraries
db = SQLAlchemy()
login_manager = LoginManager()

sched = BlockingScheduler()


def create_app(test_config=False):
    """Initialize the core application."""
    logging.basicConfig(format='%(asctime)s - %(message)s', level=logging.INFO)

    app = Flask(__name__, instance_relative_config=False)
    if not test_config:
        app.config.from_object('config.Config')
        pprint(app.__dict__)
    else:
        app.config.from_object('config.TestConfig')
        app.config.update(
            BCRYPT_LOG_ROUNDS=4,
            HASH_ROUNDS=1,
            LOGIN_DISABLED=True,
            WTF_CSRF_ENABLED=False,
            SECRET_KEY=os.urandom(25),
            TESTING=True
        )

    db.init_app(app)
    login_manager.init_app(app)

    with app.app_context():

        # Include our Routes
        from flask_bootstrap import Bootstrap
        from . import routes
        from . import auth

        # Register Blueprints
        app.register_blueprint(auth.auth_bp)
        Bootstrap(app)
        db.create_all()


        # HERE IS MY CRON JOB
        sched.add_job(cron_job_notes_recall, 'interval', seconds=1)
        sched.start()

        try:
            return app, logging
        except:

in module routes.py which is imported a few lines earlier- "from . import routes" — Szymo n, Jun 03 '20 at 21:40

score 0 · Answer 1 · answered Jun 07 '20 at 17:21

0

I'm also googling for the question answer. Got no solution yet, some ideas only: the problem root is 'This happens because the data are lost when the context (with app.app_context()) ends' One of possible solution to use Redis as an external context storage

answered Jun 07 '20 at 17:21

Vladimir Kovalev

31
1
5

I solved the problem by creating a new service that is responsible for handling my cron jobs. I think that's the easiest solution. – Szymo n Jun 26 '20 at 16:34

Add a cron job using apscheduler in Flask (flask factory)

1 Answers1