schedulers,cli: persist newline breaks in log_iter

[d4l3k]

This resolves #424

This makes it so the torchx scheduler log_iter method keeps the line breaks so downstream log streams can handle them gracefully. The current solution strips all \n characters and always adds them so it makes it impossible to do streaming visualizations of progress bars which use \r without a new line break.

WARNING: This is a change in the log_iter interface and all schedulers/downstream consumers will need to be updated.

If someone is logging from multiple workers this gets dangerous since the progress bar \r lines can clobber each other.

Test plan:

(torchx-3.10.2) tristanr@tristanr-arch2 ~/D/torchx-proj> torchx run --scheduler local_docker --wait --log utils.python --script test_tqdm.py
torchx 2022-03-15 14:26:42 INFO     loaded configs from /home/tristanr/Developer/torchx-proj/.torchxconfig
torchx 2022-03-15 14:26:42 INFO     Building workspace: file:///home/tristanr/Developer/torchx-proj for role[0]: python, image: ghcr.io/pytorch/torchx:0.1.2
dev0
torchx 2022-03-15 14:26:43 INFO     Done building workspace
torchx 2022-03-15 14:26:43 INFO     New image: sha256:9cfaf70f7143b4caef383b46c23635eaf001cbd3d9ff55335aa1ff8c5e236388 built from workspace
local_docker://torchx/torchx_utils_python-bprr9rb4k764nd
torchx 2022-03-15 14:26:44 INFO     Waiting for the app to finish...
python/0 100%|██████████| 100/100 [00:03<00:00, 32.95it/s]
torchx 2022-03-15 14:26:48 INFO     Job finished: SUCCEEDED
(torchx-3.10.2) tristanr@tristanr-arch2 ~/D/torchx-proj> torchx run --scheduler local_cwd --wait --log utils.python --script test_tqdm.py
torchx 2022-03-15 14:26:52 INFO     loaded configs from /home/tristanr/Developer/torchx-proj/.torchxconfig
torchx 2022-03-15 14:26:52 INFO     Log files located in: /tmp/torchx_0nqvqm1d/torchx/torchx_utils_python-x217jjqhbkkrgd/python/0
local_cwd://torchx/torchx_utils_python-x217jjqhbkkrgd
torchx 2022-03-15 14:26:52 INFO     Waiting for the app to finish...
python/0 100%|██████████| 100/100 [00:03<00:00, 32.95it/s]
torchx 2022-03-15 14:26:56 INFO     Job finished: SUCCEEDED

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[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (main@74560bb). Click here to learn what that means.
The diff coverage is 95.65%.

@@           Coverage Diff           @@
##             main     #425   +/-   ##
=======================================
  Coverage        ?   94.52%           
=======================================
  Files           ?       64           
  Lines           ?     3782           
  Branches        ?        0           
=======================================
  Hits            ?     3575           
  Misses          ?      207           
  Partials        ?        0           

Impacted Files	Coverage Δ
torchx/runner/api.py	96.57% <ø> (ø)
torchx/cli/cmd_log.py	94.50% <87.50%> (ø)
torchx/schedulers/api.py	94.04% <100.00%> (ø)
torchx/schedulers/aws_batch_scheduler.py	87.62% <100.00%> (ø)
torchx/schedulers/docker_scheduler.py	95.69% <100.00%> (ø)
torchx/schedulers/kubernetes_scheduler.py	92.68% <100.00%> (ø)
torchx/schedulers/local_scheduler.py	92.93% <100.00%> (ø)
torchx/schedulers/ray_scheduler.py	96.21% <100.00%> (ø)

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[facebook-github-bot]

This pull request was exported from Phabricator. Differential Revision: D34907682

[facebook-github-bot]

This pull request was exported from Phabricator. Differential Revision: D34907682

[facebook-github-bot]

This pull request was exported from Phabricator. Differential Revision: D34907682