Backport of #3997 to `release-1.6`, kube-ovn-webhook half.
The namespaced CiliumNetworkPolicy/kube-ovn-webhook carried a
cluster-spanning fromEndpoints peer on the webhook's own endpoint, so
every namespace add or delete rewrote that endpoint's policy map -- the
coupling #3983 reported against fail-closed admission webhooks. It also
depended on nothing but that one end: while the map is being recomputed
or has overflowed, the deny is the thing being rebuilt.
What ships now is one cluster-scoped
CiliumClusterwideNetworkPolicy/kube-ovn-webhook-c2bdbc146112 carrying two
specs that fail in different directions. The source-side spec is an
egressDeny on every pod endpoint naming the webhook's backend port, so it
holds while the webhook endpoint's own policy is degraded, but it relies
on Cilium performing the service DNAT ahead of its egress hook. The
target-side spec keeps the pod deny and the world deny on the webhook
endpoint, evaluated after whatever DNAT already happened, so it holds
where Cilium is not the service load balancer. Neither subsumes the
other, so the churn writes stop being load-bearing rather than going
away -- the template says so rather than claiming the coupling is
removed.
`toServices` is deliberately not used to name the Service frontend, and
the template carries the reason: Cilium resolves it only in allow rules
(pkg/policy/k8s/service.go walks spec.Egress, never spec.EgressDeny), so
an egressDeny whose only destination is an unresolved toServices reaches
the datapath with an empty L3 selector that Cilium reads as a wildcard
when the rule carries toPorts -- a cluster-wide egress outage on that
port rather than a tighter deny.
The object changes kind and name, so anything keyed on the old namespaced
CiliumNetworkPolicy/kube-ovn-webhook goes quiet with no error. The
template now also renders only while
cilium.io/v2/CiliumClusterwideNetworkPolicy is discoverable, so
`enabled: true` is no longer a promise that a policy exists; set
`enabled: false` to record a deliberate opt-out.
Assisted-By: LLM
Signed-off-by: Myasnikov Daniil <myasnikovdaniil2001@gmail.com>
Myasnikov Daniil
2e4783bf8f