CredsStore validation for RegistryAuthLocator

[zhenik]

Fixes

RegistryAuthLocator : Add additional validation for existing key credsStore but empty value

Purpose

Define behaviour for RegistryAuthLocator on empty values in config

Offer:

• fail on empty value
• ignore field with empty value & log -> return null;

Background Context

Currently experienced problems using testcontainers, I found existing issue for my problem and decided to help.
Potentially, put checks for all existing keys with empty strings

References

ref: #921

[zhenik]

Could you guys help with what behaviour should be implemented for empty values?

Options:

• fail on empty value (throw IllegalArgumentException)
• ignore field with empty value & log -> return null;
• ignore field with empty value & log -> return defaultValue;

FYI: I explicitly fail test until this behaviour will be defined and implemented

[rnorth]

Hi @NikitaZhevnitskiy
Thanks for offering to help!

When the credsStore string is blank, I think the right behaviour would be to return null from the authConfigUsingStore method. This effectively behaves as if the credsStore key is just not present at all.

I'd agree that it's a good idea to log, though - perhaps at WARN level?

Thanks!
Richard

[rnorth]

Just a couple of trivial comments from me but otherwise this is great, thank you!

[rnorth]

Great, thanks @NikitaZhevnitskiy
LGTM - will merge.

[rnorth]

Releasing this in 1.11.0 🎉