[COST-5793] remove croniter dependency

[maskarb]

Jira Ticket

COST-5793

Description

Remove croniter.

• check the length of the cron string. If it is not 5 places, let's call it not valid
• pass the string to the celery.schedule.crontab and let that do the validation. If it fails, fallback to the default.

Testing

>>> from celery.schedules import crontab
>>> from celery.schedules import ParseException
>>> def validate_cron_expression(expression, default="0 * * * *"):
...     if len(expression.split(" ", 5)) != 5:
...         print(f"Invalid cron expression: {expression}. Falling back to default {default}")
...         expression = default
...     try:
...         crontab(*expression.split(" ", 5))
...     except (ValueError, ParseException) as e:
...         print(f"Invalid cron expression: {expression}. Falling back to default {default}, Error: {e}")
...         expression = default
...     return expression
... 
>>> validate_cron_expression('hello')
Invalid cron expression: hello. Falling back to default 0 * * * *
'0 * * * *'
>>> validate_cron_expression('0 */-')
Invalid cron expression: 0 */-. Falling back to default 0 * * * *
'0 * * * *'
>>> validate_cron_expression('0 */- * * *')
Invalid cron expression: 0 */- * * *. Falling back to default 0 * * * *, Error: empty filter
'0 * * * *'
>>> validate_cron_expression('0 */ * * *')
Invalid cron expression: 0 */ * * *. Falling back to default 0 * * * *, Error: empty filter
'0 * * * *'
>>> validate_cron_expression('0 * * * *')
'0 * * * *'
>>> validate_cron_expression('0 /* * * *')
Invalid cron expression: 0 /* * * *. Falling back to default 0 * * * *, Error: Invalid weekday literal '/*'.
'0 * * * *'
>>> validate_cron_expression('0 15/ * * *')
Invalid cron expression: 0 15/ * * *. Falling back to default 0 * * * *, Error: Invalid weekday literal '15/'.
'0 * * * *'
>>> validate_cron_expression('0 15 * * *')
'0 15 * * *'
>>> 

Release Notes

• proposed release note

* [COST-5793] remove croniter dependency

[maskarb]

/retest

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.2%. Comparing base (cc07aa2) to head (8a919f4).
Report is 1 commits behind head on main.

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #5435   +/-   ##
=====================================
  Coverage   94.2%   94.2%           
=====================================
  Files        371     371           
  Lines      31542   31542           
  Branches    3378    3378           
=====================================
+ Hits       29699   29700    +1     
+ Misses      1198    1196    -2     
- Partials     645     646    +1