[miki3421]

Tenant action pods in a full 0.9.0 installation can reach shared, unauthenticated Kafka and ZooKeeper endpoints. This change restricts their ingress to the required control-plane and monitoring pods while retaining existing component versions, protocols and PVC contents.

Closes apache/openserverless#276.

Changes

• Add same-namespace NetworkPolicies with explicit client/port allowlists. Every allowed selector excludes pods carrying user-action-pod, regardless of its value.
• Apply policies before workloads and wait for StatefulSet rollout. A template revision rolls legacy messaging pods once to close existing connections.
• Automatically reconcile enabled ZooKeeper then Kafka during operator resume and Whisk updates; propagate errors and leave disabled/slim components untouched.
• Add 19 focused lifecycle/policy regression tests and MESSAGING_SECURITY.md.

Validation

• Re-ran the complete operator unittest suite before publication: 66/66 passed.
• Existing synthetic K3s lab validation: 16/16 tenant connections reachable before the patch and denied after automatic operator resume.
• Trusted clients, metrics, action-labelled spoofing and cross-namespace checks: 8/8 passed.
• Alpha/Beta: 15/15; Redis Lua: 84/84; Streamer: 24/24; scheduled actions and both frontends remained functional.
• Repeating operator resume preserved Kafka/ZooKeeper pod identities. Application source and deployed action definitions remained unchanged.

The lab used an unpublished local image and exercised image replacement/restart plus the actual Kopf resume handler. The exact ops update operator CLI command and a new full installation were not repeated in this follow-up. The first rollout temporarily interrupted messaging while consumers/invoker health recovered.

Deployment requirements and review notes

NetworkPolicy enforcement is required. Standard Kind networking without an enforcing policy provider does not establish this boundary. Administrator-added broad allow policies and compromised trusted control-plane pods remain outside the ordinary-tenant protection.

The targeted Daybreak diff review confirmed the automatic-upgrade correction and identified one remaining Medium teardown limitation: normal owner-backed Whisk deletion can bypass the explicit policy-last helper when saved process state is absent. Owner garbage collection does not guarantee policy deletion order. The contributor accepted this as non-blocking; this PR documents the limitation and does not fix it.

No release workflow, image pin, component upgrade, or application-code change is included. This branch is hosted on the contributor's personal fork.