Sendmail from logger

As Flask is uses the standard logging library of Python, we an also use the logging.handlers.SMTPHandler andconfigure the logger to send an email every time there is an ERROR-level log message.

from flask import Flask
import logging
app = Flask(__name__)
from logging.handlers import SMTPHandler

mail_handler = SMTPHandler(
    mailhost='127.0.0.1',
    fromaddr='server-error@example.com',
    toaddrs=['gabor@localhost'],
    subject='Application Error'
)
mail_handler.setLevel(logging.ERROR)
mail_handler.setFormatter(logging.Formatter(
    '[%(asctime)s] %(levelname)s in %(module)s: %(message)s'
))
if not app.debug:
    app.logger.addHandler(mail_handler)

@app.route("/")
def main():
    app.logger.debug("Some debug message")
    app.logger.info("Some info message")
    app.logger.warning("Some warning message")
    app.logger.error("Some error message")

    return "Hello World"