calicoctl has silent failure if passed in config file does not exist

[tmjd]

When attempting to pass in a config file to calicoctl node run I had misnamed the file and could not understand why the configuration in my file was being ignored. There is no indication that a passed in file does not exist.

Expected Behavior

If a file is passed with --config to calicoctl and the file does not exist then an error message will be printed. I think it would also be good to just exit in that case too but can understand not exiting to keep the current behavior.

Current Behavior

Passing in a non-existent file to calicoctl --config flag produces no message or error.

Possible Solution

If a non-default value is received from the --config option and the file does not exist then print an error message.

Steps to Reproduce (for bugs)

1. Use calicoctl where the non-default values do not access the datastore
2. Run `calicoctl get node --config non-existent-file.yaml
3. See no indication that file does not exist.

Context

See summary

Your Environment

• Calicoctl version v1.3.0

[bcreane]

Migrated a copy of this issue to projectcalico/calicoctl. See: 1678