Glossary & concepts

Concepts

Short explanations of concepts used across the test plans — networking, storage, secrets management, and more — for anyone who does not work with them every day.

macvtap (NOT supported) vs. OVN-K localnet (official path)

macvtap gives a VM its own MAC — but is NOT officially supported in OpenShift Virtualization. The correct approach is OVN-K localnet.

WaitForFirstConsumer (StorageClass binding mode)

A PVC stays deliberately 'Pending' until a pod/VM actually uses it — not an error!

NodeNetworkConfigurationPolicy (NNCP)

Declarative node network configuration via the Kubernetes API — instead of manual nmcli commands.

OVN-Kubernetes & br-ex

OpenShift's default network plugin uses an OVS bridge (br-ex) that takes over the physical NIC.

OVN-Kubernetes (OVN-K) is the default CNI plugin in OpenShift. It uses Open vSwitch (OVS) internally and attaches the node's primary NIC to a bridge named br-ex. The node IP then sits on br-ex, not directly on the physical NIC (e.g. eno2). That is why ip addr show eno2 may show no IP, while ip addr show br-ex does.

✓ ADVANTAGES

Fully integrated software-defined networking for the whole cluster
Supports NetworkPolicies, multi-tenancy, and service routing natively

⚠ LIMITATIONS

The physical NIC is blocked for other uses (e.g. a second Linux bridge)
Changes to br-ex are risky because OVN-K manages and may overwrite them

📍 WHY IT MATTERS HERE

Explains why eno2 cannot be used directly for VM bridges on this Hetzner SNO (PRE-02/PRE-03), and why OVN-K localnet is the officially supported path for physical LAN access instead (TC-NET-002).

HCP: does every hosted cluster need its own public IP?

No — only the API server (with the KubeVirt/on-prem provider) needs a dedicated IP or dedicated port. OAuthServer, Konnectivity, and Ignition already share the management cluster's existing Ingress route today.

Sealed vs unsealed — why pods stay 0/1 Ready

A sealed OpenBao holds only encrypted data and refuses almost every request — the pod runs but is not Ready. Unsealing reconstructs the barrier key.

KV v2 — versions, soft delete, and check-and-set (CAS)

KV v2 keeps a version history per secret and can require a version number on every write — a write is a whole new version, not a field update.

Kubernetes auth method — SA token in, OpenBao token out

Pods authenticate with their projected ServiceAccount JWT; OpenBao validates it against the kube-apiserver and returns a short-lived token carrying the role's policies.

OpenBao vs Vault — why /vault/ still appears everywhere

OpenBao is the Linux Foundation fork of HashiCorp Vault and keeps API and tooling compatibility — so UI routes, sidecar paths, and third-party integrations still say 'vault'.

Raft integrated storage — leader, quorum, snapshots

OpenBao stores data itself and replicates it with the Raft consensus protocol — no external database, but quorum rules apply.

📚 Glossary & concepts

Glossary & concepts