[AIRFLOW-4085] FileSensor - adding wildcard option

[zacharya19]

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Changing FileSensor to use glob in order to allow wildcard and more functionality in this sensor.

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[codecov-io]

Codecov Report

Merging #5358 into master will decrease coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #5358      +/-   ##
==========================================
- Coverage   79.03%   79.03%   -0.01%     
==========================================
  Files         481      481              
  Lines       30212    30210       -2     
==========================================
- Hits        23877    23875       -2     
  Misses       6335     6335

Impacted Files	Coverage Δ
airflow/contrib/sensors/file_sensor.py	100% <100%> (ø)	⬆️

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[ashb]

Suggested change

	dir_ = tempfile.mkdtemp()
	dir = tempfile.mkdtemp()

The diff is much easier to read and easier to review if you don't make changes like this. Please revert it.

[ashb]

This isn't an "option" for wildcard but support for them always. This is probably okay (as most people don't put * or ? etc in paths, but at the very least this should be mentioned in UPDATING.md

[zacharya19]

@ashb done.

[OmerJog]

@zacharya19 can you resolve the conflict?

[zacharya19]

@OmerJog Done.

[ashb]

Largely looking okay, but a few changes to make. please mention/ping me when you rebase as otherwise I might miss the update.

[zacharya19]

@ashb Fixed conflicts and answered your comments.

[ashb]

Code looks good.

Tests were failing, I've restarted the tests, hopefully it was just a transient failure.

[ashb]

Merged. Now I just need to decide if we merge this in for release with 1.10.6 or not. It is technically a breaking change, but it is just very unlikely to affect anyone. I think.

[NBardelot]

FYI this behaviour is inconsistent.

If anyone like me comes to this PR after looking at the glob() behaviour, this cannot work for hooks that make use of a remote FS (like SFTPHook for example). As the Python documentation states that glob() uses a mix of os.scandir() and fnmatch.fnmatch() which make the code proposed here only adapted to a local FS.

Thus, trying to use a path with a glob pattern and a hook to a remote FS will have a random effect: either you're lucky and the glob() will not find the equivalent path locally and just return that the path does not exist (the sensor will never trigger); or in a worse case scenario you might trigger the sensor for a file that exists locally but not on the remote FS as expected...