Batch: arraySize and child jobs

[rafcio19]

Closes #6512

[rafcio19]

Technically it does satisfy requirements from #6512 but doing it on the response, rather than in the model, feels doesn't feel quite right. I originally tried with a deepcopy of the Job object but that didn't play nicely with threading.
@bblommers can you give this a once over?

[bblommers]

@rafcio19 If I understand the docs correctly, we should actually execute the same job x times. So the logic is quite different - it's not just the response format that needs to change.

As a potential solution:
Can we create a new ArrayJob class, that in the run-method creates x regular Jobs that execute the actual script?

Note that I haven't looked at the implementation in a while, so I don't know how feasible it is. But that's probably the most similar to how AWS behaves.

[bblommers]

BTW, I would be happy to have a go at the implementation, I just don't know when/if I have time in the coming days.

[rafcio19]

Thanks for the tips, leave it with me for another while.

[oliver-helix]

Hey @rafcio19 @bblommers
Thanks so much for your hard work here. Any update since July?

[rafcio19]

Hey chaps, I haven't had much time to devote to moto since the summer. If someone else wants to have a go then please do; or you could 🤞 and give me a few weeks.

[bblommers]

Hey @rafcio19, I just had a crack at it. Instead of an ArrayJob, I realized it was easier to just create additional regular jobs in the submit_job-method. The parent-job itself will not be executed, but has a list of child-jobs.
When describing a job that happens to have any child-jobs, we can check immediately check the status of those child-jobs - so they are no longer hardcoded to 'SUCCEEDED'.

Based on my testing, this is all in-line with how AWS behaves

[rafcio19]

Go nuts @bblommers, I've had it long enough. Will try to pick up more moto issues in the near future

[codecov]

Codecov Report

Merging #6541 (301d385) into master (9767f02) will increase coverage by 0.00%.
Report is 22 commits behind head on master.
The diff coverage is 100.00%.

@@           Coverage Diff            @@
##           master    #6541    +/-   ##
========================================
  Coverage   95.81%   95.82%            
========================================
  Files         821      826     +5     
  Lines       80624    81042   +418     
========================================
+ Hits        77249    77655   +406     
- Misses       3375     3387    +12     

Flag	Coverage Δ
servertests	36.73% <17.77%> (-0.10%)	⬇️
unittests	95.76% <100.00%> (+0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
moto/batch/models.py	90.98% <100.00%> (+0.20%)	⬆️
moto/batch/responses.py	100.00% <100.00%> (ø)
moto/batch_simple/models.py	96.29% <100.00%> (+1.05%)	⬆️

... and 27 files with indirect coverage changes

[github-actions]

This is now part of moto >= 4.2.6.dev30