Expose flag to explicitly disable cloud-provider=external kubelet argument

[anmazzotti]

The coud-provider=external kubelet argument was hardcoded.

I did implement a flag to explicitly set it. Note that this will change the current behavior, as the default value for this new flag is false. If this is not visible, I can reverse the flag to keep the current behavior in place.

The same flag is also used to disable the embedded cloud controller (since the external one will be used)

[mkmik]

I'd prefer to not introduce a backward incompatible change. Can we define this setting with a polarity that would have natural default that preserves backward compatibility?

[richardcase]

I agree with @mkmik , we need to preserve the existing behaviour which is to set the cloud provider to external.

Should we allow the user to set a value for the cloud-provider to something else (e.g. aws)? Or is this just above having an option to remove this?

[anmazzotti]

Thank you @mkmik and @richardcase for the feedback.
I agree that is not that user friendly to change the behavior now.

I pushed one last commit to reverse the flag, so that cloud-provider=external will need to be explicitly disabled.

[richardcase]

LGTM 👍