Add script to validate remote object store paths

[irenedea]

What does this PR do?

Adds a script that validates remote object store paths using composer utility functions.

This is helpful for debugging especially on remote runs.

What issue(s) does this change relate to?

Before submitting

• Have you read the contributor guidelines?
• Is this change a documentation change or typo fix? If so, skip the rest of this checklist.
• Was this change discussed/approved in a GitHub issue first? It is much more likely to be merged if so.
• Did you update any related docs and document your change?
• Did you update any related tests and add any new tests related to your change? (see testing)
• Did you run the tests locally to make sure they pass?
• Did you run pre-commit on your change? (see the pre-commit section of prerequisites)

[j316chuck]

qq: Is this script supposed to be used locally in interactive session since there already exists an mcli yaml?

[irenedea]

@j316chuck the mcli yaml that i was using only supports s3, so i figured this would be an easy way to check all backends easily and through composer as well. Though, if this script fails, it doesn't necessarily rule out composer issues. I'll write an mcli yaml for this as well.

[dakinggg]

Can we make this part of the library instead of a script? similar to composer_collect_env

[irenedea]

@dakinggg good suggestion! so it would both in the library as well as a script, yeah?

[dakinggg]

Yeah, exact same as composer_collect_env setup

[irenedea]

@dakinggg I think the best move would be to create a list_remote_objects (that does exactly what the script does now, but returns a list of objects if objects are found). This would probably belong in file_helpers.py. If we add this function to file_helpers.py, do you have any thoughts on where to put the script?

[dakinggg]

Can you define console_scripts that don't use main? It kinda looks like you can, but I've never tried it. If so, can just define a function in file_helpers.py that prints out what you want, and define the console_scripts command to point to that function

[irenedea]

@dakinggg Tried it, but it won't work--it needs to a be a function that takes no arguments. So we could (1) keep a tiny script in scripts/validate_remote_path.py and have it call the list_remote_objects function in file_helpers.py (2) create a small function that takes no args in file_helpers.py that calls list_remote_objects and use that for the console script. wdyt?

[dakinggg]

I think Its possible to set it up with args parsed by argparse. because the composer launcher is set up the same way. See the main function in there that parses args