Workflow of the Python Pipeline in a nutshell¶

This is a short explanation what happens, if you click on "Run script" inside SeaTable.

SeaTable Server¶

To initialize the Python Pipeline, SeaTable-Server makes a POST request to the API-endpoint /run-script/ of the scheduler. This call is authenticated by the shared secret, defined in dtable_web_settings.py. Every two seconds (and for max. 15 minutes), the SeaTable Server checks the status of the script execution by calling /run-script/<script_id> from the scheduler.

SeaTable Scheduler¶

The scheduler creates a new task in the mariadb database. The scheduler calls the API-endpoint /function/run-python of the starter. Now the scheduler waits for the starter's POST request to /script-result/, which indicates that the run has finished. The scheduler then writes the duration and the output to the database.

SeaTable Starter¶

The starter downloads the python script directly from SeaTable Server and saves the script to a temporary folder on the hard drive of the host. The starter now starts a python-runner container and mounts the script as input. After completion the runner container is deleted and the result data is sent to the scheduler by making a POST request to /script-result/.

SeaTable Runner¶

SeaTable runner executes the python script and writes the output to the same temporary folder on the host. After that the container stops.

Important points¶

• dtable-web only queries the result as long as the browser is open (manual execution).
• if an automation starts a python script, SeaTable Server waits max. 15 minutes for the run to finish.
• starter and runner communicate via the exchange directory. this must be available as a volume to both containers
• starter and scheduler communicate via api calls.
• the python runner is stopped after 15 minutes at the latest
• the scheduler has a cleanup process to invalidate work orders in the database that run for longer than 15 minutes.
• the task is stored in the database for some days (30 days by default)