[KubernetesExecutor] make the number of log lines to read from the worker pod configurable

[XD-DENG]

Now the KubernetesExecutor supports method get_task_log() (in main branch). However, the number of lines to read is hard-coded to be 100.

It can be imagined that in many cases people may need more logs. And it would be nice to make this number of log lines to read from worker pod configurable. So that users can adjust according to their certain environment.

---

^ Add meaningful description above

Read the Pull Request Guidelines for more information.
In case of fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
In case of a new dependency, check compliance with the ASF 3rd Party License Policy.
In case of backwards incompatible changes please leave a note in a newsfragment file, named {pr_number}.significant.rst or {issue_number}.significant.rst, in newsfragments.

[XD-DENG]

Hi @dstandish , mind helping take a look at this one? Thanks a lot!

[dstandish]

maybe running_pod_tail_lines?

because it seems pretty rare that you'd want to customize this, just to avoid another config param i'm tempted to suggest using a class constant that you could monkey patch in airflow local settings... but... i don't feel strongly about it.

[XD-DENG]

Thanks @dstandish . Renamed as suggested.

I fully understand the concern about adding another config param, but I still find this necessary. 100 lines seems reasonable for most cases, but when user want to have more flexibility, e.g. debugging their jobs, more log lines will be needed (this happens to me often in real works).

Comparing with different methods, like the one you shared above (class constant and monkey patch in local settings), I still find adding it as a config param is better.

Please let me know if these clarify, or should you have any other concern. Thanks a lot!

[github-actions]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed in 5 days if no further activity occurs. Thank you for your contributions.