Wolkenbruch

Checks the weather forecast for a configurable place and sends an e-mail reminder to pack your rain gear if precipitation is forecast.

Wolkenbruch makes use of the MET Norway API, and uses OpenStreetmap to find the location from place names.

Dependencies

Wolkenbruch is written in Python 3, and depends on the Python modules geocoder, requests and yaml.

Installation

• using pip or similar:

pip install wolkenbruch

Configuration

Copy the example configuration file wolkenbruch.yml.template to a suiteable location, depending on your operating system:

• on Linux systems:
  • system-wide configuration: /etc/wolkenbruch.yml
  • per-user configuration:
    • ~/.config/wolkenbruch.yml OR
    • ${XDG_CONFIG_HOME}/wolkenbruch.yml
• on MacOS systems:
  • per-user configuration:
    • ${XDG_CONFIG_HOME}/wolkenbruch.yml
• on Microsoft Windows systems:
  • per-user configuration: %APPDATA%\wolkenbruch.yml

Adapt the configuration:

• Change the place the forecast searches for. For bigger cities their name might be sufficient (Unicode is supported), e.g. “Helsinki”. When it comes to smaller places, or places that share their name with other places in different parts of the world, you might have to add a country, state or county name, e.g. ”Springfield, Fife”.
• Adapt the SMTP host and credentials (leave user and password empty if not authentication is required). Be careful: the credentials are (obviously) saved in plain-text. Protect access to the configuration file, e.g. on a GNU/Linux or MacOS system using chmod 0600 "~/.config/wolkenbruch.yml".
• Set the sender and receiver e-mail address (they can and often will be the same address)
• If you feel like it, change the subject line and message body of the e-mail. The message body can contain Python string formatting code for a float variables a and m (the average and maximum precipitation rates over the next 14 hours, in mm/h).
• Adjust the amount of rain you can stand: average_precipitation_rate_threshold is the average precipitation rate over the next 14 hours (in mm per hour) that has to be exceeded to send you a reminder, max_precipitation_rate_threshold the highest single hourly value that makes you want to not forget your rain gear.
• The verbose flag toggles whether wolkenbruch prints a status or operated silently.

# example configuration file
# (/etc/wolkenbruch.yml, ~/.config/wolkenbruch.yml,
#    %APPDATA%/wolkenbruch.yml, ${XDG_CONFIG_HOME}/wolkenbruch.yml)
place: Helsinki
average_precipitation_rate_threshold: 0.1
max_precipitation_rate_threshold: 0.5

email-to: myself@whereever.com
email-from: me@whereever.com
email-subject: Pack your rain gear!
email-message: The average forecast precipitation rate for today is {a:0.2f}, maximum {m:0.2f} mm/h.

smtp-host: localhost:587
smtp-user: foobar
smtp-password: BARFOO

user-agent: wolkenbruch

verbose: False

Usage

Run wolkenbruch to check the precipitation for the next 14 hours and send you an e-mail reminder. Ideally, set up a cron job or a systemd timer to run wolkenbruch e.g. every morning.

Systemd timer

Copy wolkenbruch.service and wolkenbruch.timer from extra/systemd/ to /etc/systemd/user/ or ~/.config/systemd/user/ and enable the timer to run wolkenbruch at 6:30 every morning:

systemctl --user daemon-reload
systemctl --user enable --now wolkenbruch.timer 

If you want the systemd timer to trigger when you’re not logged in, enable lingering for your user:

sudo loginctl enable-linger USERNAME