We can use framework.ExpectError() for checking the expected error
happens. However Expect(err).To(HaveOccurred()) can be used instead
and that makes the e2e test code unreadable.
This adds the check to use framework.ExpectError() for readable code.
The framework/ssh.go code was heavily used throughout the framework
and could be useful elsewhere but reusing those methods requires
importing all of the framework.
Extracting these methods to their own package for reuse.
Only a few methods had to be copied into this package from the
rest of the framework to avoid an import cycle.
This is part of the transition to using framework/log instead
of the Logf inside the framework package. This will help with
import size/cycles when importing the framework or subpackages.
Use the same pattern everywhere in the e2e test
harness, use busybox (from dockerhub) instead
of using the one from k8s.gcr.io registry.
Change-Id: I57c3b867408c1f9478a8909c26744ea0368ff003
Kenichi Omichi