docker-pycron

This is a generic python docker used to run custom scripts and what not. Docker Hub URL

Usage

Please note that this docker uses Python 3.7 and has the following packages installed:

cron
ffmpeg
imagemagick
gifsicle
logrotate

Additional packages can be installed in the docker using apt-get install, or you can request they be added to the docker image.

Volume Maps

Map the /work directory to wherever you want your scripts stored and the /share directory to wherever you want saved data to go (not needed, but can be useful).

First time setup

The first time you install the container, a config.yaml and example.py file will be placed in your mapped work volume. These just show the syntax for using the container. Once you're ready to set everything up, you can delete or modify those files. The next time the container is installed or restarted, it will look for the existance of config.yaml and will only create a new example version if one does not already exist.

Scheduling Scripts

In your /work directory, create a file called config.yaml. This config file will define all of your scripts and when they should be scheduled. Currently minutes, hours, and days are supported.

For exampe, if you have a script in your /work directory called my_script.py, and you wanted this to run every two hours, your config.yaml would look like the following:

my_script:
  schedule:
    hours: 2

If you had a second script called fast_script.py that you wanted to schedule to run eevry five minutes, you would modify your config.yaml to look like the following:

my_script:
  schedule:
    hours: 2

fast_script:
  schedule:
    minutes: 5

Note that any time you edit your config.yaml file you will need to restart the container. Script edits can be done on-the-fly without restarts.

Logging scripts

You can add print messages to your scripts which are then printed to /var/log/syslog (useful for running on unraid so you can view your script outputs in the log window). To do this, simply add the following to the top of your script(s):

from pycron import LOGGER

You can then create log statements by using the LOGGER.[LEVEL] syntax where [LEVEL] can be debug, info, warning, or error. So to write an error message to the log, you would use the following syntax (instead of using print()):

LOGGER.error("Oh no, something went wrong!")

Custom Python Packages

If you want to install custom python packages without needing to perform a pip install on every docker restart, you can add a file called my_requirements.txt to your /work directory. You may add packages here with a version number. For example, If you want to install a specific version of the sqlalchemy but just want a minimum version of requests, your my_requirements.txt file would look like the following:

sqlalchemy==1.2.12
requests>=2.0.0

Each line represents a package and you can add as many as you'd like!

By default, the following python packages are installed:

python-crontab
ruamel.yaml