kwctl does not fail in case it can not read the docker config.json

[Martin-Weiss]

Is there an existing issue for this?

• [X] I have searched the existing issues

Current Behavior

During troubleshooting kwctl image pull from authenticated registry I had to specify the parameter --docker-config-json-path and had the false understanding that this does not only take the path to a config.json but I can also specify the json i.e. via --docker-config-json-path /root/oci/reg-auth.json

Unfortunately the putput of kwctl did not give any info that the file could not be read and just in the strace I could find out that it tried to read /root/oci/reg-auth.json/config.json

Expected Behavior

In case the config.json specified can not be read / does not exist - kwctl should thrown an error message for the user.

Steps To Reproduce

Use kwctl and specify a non existing or non readable --docker-config-json-path

Environment

- OS: Linux
- Architecture: x86_64

Anything else?

No response