Procedures

What are procedures?

A procedure should run in an infinite loop to perform some function of the system - e.g., sampling from a sensor, controlling an actuator, making some decision based on the result of other procedures, etc.

The function of the mainloop is to make sure that all procedures run at all times - starting them on program start, restarting them if they crash, sending a graceful teardown notice before the program is shut down.

All procedures are located inside src/procedures/. You can use src/procedures/dummy_procedure.py as an example of how to write a procedure.

How to define a procedure?

Create a new file in src/procedures/new_procedure.py:

import src
 
def run(config: src.types.Config, name: str) -> None:
    """..."""
 
    logger = src.utils.Logger(config, origin=name)
    messaging_agent = src.utils.MessagingAgent()
    ...

Inside src/main.py, add a LifecycleManager for the new procedure to the list of lifecycle managers:

lifecycle_managers: list[src.utils.LifecycleManager] = [
    # existing lifecycle managers
    ...
    src.utils.LifecycleManager(
        config=config,
        entrypoint=src.procedures.new_procedure.run,
        name="new-procedure",
        variant="procedure",
    ),
]

Look at the src/procedures/dummy_procedure.py for an example of what a procedure can look like.

Exponential Backoff

The usage of the ExponentialBackoff class is documented here.

Over-the-Air Updates Configuration