Replace settings variable with function

[SimonBoothroyd]

Description

This PR replaces the 'dangerous' settings field exposed by the bespoke executor with a more reliable function that returns the most up-to-date values.

The object returned by current_settings() should not be modified as the changes will have no effect. Instead the apply_env context manager should be used e.g.

with Settings(
    BEFLOW_FRAGMENTER_WORKER_N_CORES=...,
    BEFLOW_FRAGMENTER_WORKER_MAX_MEM=...
).apply_env():

    settings = current_settings()

Possibly fixes #130

Status

• Ready to go

[jthorton]

The info in the redis_connection object seems to be the same as that in the settings class and this logic seems to be repeated for each app, would it make sense to have the configure_celery_app just call the current_settings function and get the relavent info?

[SimonBoothroyd]

Yeah I think either having configure celery return a tuple of both the app and redis connection, or adding a new configure_redis method that also checks for the executor key you mentioned in slack / any other validation would be a great shout!

I think I have a slight preference for the latter, but not by much 🙂

[SimonBoothroyd]

We should probably handle this in a new PR though so it doesn't get buried here! 😅

[jthorton]

@SimonBoothroyd thanks for the quick fix, can confirm this now works on linux as expected!