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!

Every StorageClass has a volumeBindingMode: either 'Immediate' (the volume is created as soon as the PVC is created) or 'WaitForFirstConsumer' (the volume is created only when a pod wants to mount the PVC). LVM Storage uses WaitForFirstConsumer by default so the volume is created on the node where it is needed — important on multi-node clusters, less relevant on SNO but still active.

✓ ADVANTAGES

Prevents volumes from landing on the wrong node (on multi-node clusters)
Saves storage when PVCs are created but never used

⚠ LIMITATIONS

PVC stays 'Pending' without a pod — looks like an error, but is normal
virtctl image-upload and DataVolume clones stall without a consumer pod
Sometimes requires an explicit consumer pod just to force binding

COMPARISON

WaitForFirstConsumer: Volume is created only when the first pod mounts the PVC. Default for local storage (LVM, hostpath).

Immediate: Volume is created as soon as the PVC is created, regardless of a consumer. Required for virtctl image-upload (hence lvms-vg1-immediate StorageClass in PRE-06 / TC-VM-002).

📍 WHY IT MATTERS HERE

Explains why test PVCs in PRE-06 and clone operations in TC-STG-001 initially show 'Pending', and why ISO uploads in TC-VM-002 need a dedicated StorageClass with Immediate binding.

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.

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