The previously existing e2e GMSA test really only tests a small part of the
whole GMSA set up process, namely that once the API has inlined the GMSA
contents in the pod's spec, and sent that to a worker's kubelet, then the
kubelet passes that down to the runtime.
This new test, in contrast, really tests the whole thing, i.e. deploying the
admission webhook, then deploying a GMSA custom resource, and using that
resource within a pod.
The downside of this test though, is that it does need to make a lot of
assumptions about the cluster it runs against, notably that it runs on a worker
node that's already been joined to a working Active Directory domain (there are
other assumptions, all documented at the beginning of the test file); for that
reason, it is only intended to ever be run against an AKS cluster with the
custom AKS extension from
https://github.com/kubernetes-sigs/windows-testing/pull/98.
Note that this test doesn't aim at testing every edge-case, such as
a pod trying to use a GMSA it doesn't have access to; the webhook has
its own tests for these. This test's goal is to ensure the happy path
doesn't break.
Signed-off-by: Jean Rouge <rougej+github@gmail.com>