Flag --export has been deprecated and is now removed in oc 4.6

[michaelsauter]

See e.g. https://www.reddit.com/r/openshift/comments/fyms4k/flag_export_has_been_deprecated/ and kubernetes/website#14432.

The flag has been removed in openshift-clients-4.6.0-202006250705, even though I can't really find how that change was introduced, probably by a bump of k8s. There is no mention whatsoever in any release notes I can find. OpenShift 4.6 has been released three days ago: https://www.openshift.com/blog/red-hat-openshift-4.6-is-now-available.

Looks like we need to use plain get and implement the --export functionality ourselves. I think we already do this partially, but there could be some nasty details.

[michaelsauter]

Update no.1: I ran make test without --export against an OpenShift 3.11 cluster and it passes. However, the E2E tests do not cover all supported resources right now so I would take it with a grain of salt.

[michaelsauter]

Update no.2: Looking at https://github.com/opendevstack/tailor/blob/master/pkg/openshift/item.go#L18-L39, it looks like we handle all fields that are outside /spec already that should be excluded. So we'd only need to clean up if --export removed some field under /spec that would now be shown.