If the node authorizer is active, RBAC rules are not needed. But if it's
disabled, kubelet needs to get permission through RBAC. In contrast to the
authorizer code which is a bit more flexible and isn't directly tied to the
current kubelet implementation (i.e. it allows list+delete instead of just
deletecollection), the RBAC entry is just for what the current kubelet does
because it's a bit easier to change.
In reality, the kubelet plugin of a DRA driver is meant to be deployed as a
daemonset with a service account that limits its
permissions. https://kubernetes.io/docs/reference/access-authn-authz/service-accounts-admin/#additional-metadata-in-pod-bound-tokens
ensures that the node name is bound to the pod, which then can be used
in a validating admission policy (VAP) to ensure that the operations are
limited to the node.
In E2E testing, we emulate that via impersonation. This ensures that the plugin
does not accidentally depend on additional permissions.
When a resource gets deleted during migration, the SVM SSA patch
calls are interpreted as a logical create request. Since the object
from storage is nil, the merged result is just a type meta object,
which lacks a name in the body. This fails when the API server
checks that the name from the request URL and the body are the same.
Note that a create request is something that SVM controller should
never do.
Once the UID is set on the patch, the API server will fail the
request at a slightly earlier point with an "uid mismatch" conflict
error, which the SVM controller can handle gracefully.
Setting UID by itself is not sufficient. When a resource gets
deleted and recreated, if RV is not set but UID is set, we would get
an immutable field validation error for attempting to update the
UID. To address this, we set the resource version on the SSA patch
as well. This will cause that update request to also fail with a
conflict error.
Added the create verb on all resources for SVM controller RBAC as
otherwise the API server will reject the request before it fails
with a conflict error.
The change addresses a host of other issues with the SVM controller:
1. Include failure message in SVM resource
2. Do not block forever on unsynced GC monitor
3. Do not immediately fail on GC monitor being missing, allow for
a grace period since discovery may be out of sync
4. Set higher QPS and burst to handle large migrations
Test changes:
1. Clean up CRD webhook convertor logs
2. Allow SVM tests to be run multiple times to make finding flakes easier
3. Create and delete CRs during CRD test to force out any flakes
4. Add a stress test with multiple parallel migrations
5. Enable RBAC on KAS
6. Run KCM directly to exercise wiring and RBAC
7. Better logs during CRD migration
8. Scan audit logs to confirm SVM controller never creates
Signed-off-by: Monis Khan <mok@microsoft.com>
