Oke Multihome Deployer

OKE Multihome Deployer

Scope

Use this skill after an OKE node pool already has GVA secondary VNIC profiles attached. This skill deploys and verifies Multus-based pod multihoming; it does not create or update GVA node pools.

If the user needs to create or update the node pool secondary VNIC profiles, use oke-gva-deployer first, then return here.

Supporting references:

• validation-report-template.md — standard final validation report structure.

Core Workflow

1. Confirm target cluster/context and auth.
   • Prefer explicit OCI_CLI_PROFILE and OCI_CLI_AUTH; when using OCI security-token auth, pass --auth security_token or set OCI_CLI_AUTH=security_token.
   • If kubectl fails with exec: executable oci failed, ask the user to refresh the OCI session before applying anything.
2. Auto-discover cluster, node pool, and subnet data before generating YAML.
   • Use scripts/discover-oke-multihome.py.
   • Prefer --cluster-id when the user provides it; otherwise try --context, then --cluster-name with --compartment-id.
   • The discovery script queries OKE node pools and fetches all referenced placement and secondary VNIC subnets.
   • Use the discovered node names for --pod NAME=NODE_NAME entries.
3. Verify prerequisites from Kubernetes and node-side checks.
   • OKE CNI must be OCI_VCN_IP_NATIVE.
   • Worker nodes must expose secondary VNIC interfaces. Treat enp1s0 and enp2s0 as common defaults, then confirm the actual interface names from discovery or node-side evidence before applying manifests.
   • OCI CNI binaries should exist on nodes: oci-ipam, oci-ipvlan, oci-ptp.
   • The standard ipvlan CNI binary is needed when using a plain ipvlan secondary NAD.
4. Install Multus thick plugin if absent.
   • Upstream manifest used in this workflow: https://raw.githubusercontent.com/k8snetworkplumbingwg/multus-cni/master/deployments/multus-daemonset-thick.yml
   • TODO(live validation): pin this manifest to a tested Multus release tag after validating it against the target OKE Kubernetes version. Keep using the repo's current manifest reference until that live validation is complete.
5. Generate or edit the deployment manifest.
   • Use scripts/generate-multihome-manifest.py for repeatable YAML.
   • Default network NAD: kube-system/gva-default-network, using oci-ipvlan on the first secondary VNIC path.
   • Secondary NAD: workload namespace scoped, using ipvlan on the second secondary VNIC path with oci-ipam.
6. Apply and verify.
   • Use fully qualified images such as docker.io/nicolaka/netshoot:v0.13; CRI-O may reject short image names.
   • Check pod annotation k8s.v1.cni.cncf.io/network-status.
   • Exec ip -br addr in each pod and ping the peer net1 IP both directions.
   • Use validation-report-template.md for the final validation report, whether validation passed, failed, or remains incomplete.

Discovery

Run discovery before manifest generation:

OCI_CLI_PROFILE=<oci-profile> OCI_CLI_AUTH=<oci-auth-mode> \
python3 <skill>/scripts/discover-oke-multihome.py \
  --cluster-id <cluster_ocid> \
  --region <region> \
  --pretty > oke-multihome-discovery.json

If the current kubeconfig contains the cluster OCID in its exec user args, use:

OCI_CLI_PROFILE=<oci-profile> OCI_CLI_AUTH=<oci-auth-mode> \
python3 <skill>/scripts/discover-oke-multihome.py \
  --context <kubectl_context> \
  --region <region> \
  --pretty

Use the JSON output to pick:

• Node pool with GVA secondaryVnics.
• Primary placement subnet(s), for node placement context.
• Secondary VNIC subnet IDs/CIDRs, for deciding which interface path maps to each pod network.
• Up to two ready node names for pinned smoke-test pods.

Do not guess subnet CIDRs or node names when discovery can retrieve them.

Manifest Generation

Generate a two-pod test manifest:

python3 <skill>/scripts/generate-multihome-manifest.py \
  --namespace gva-multihome-test \
  --default-interface <confirmed-first-secondary-vnic-interface> \
  --secondary-interface <confirmed-second-secondary-vnic-interface> \
  --pod gva-multihome-a=<node-name-a> \
  --pod gva-multihome-b=<node-name-b> \
  > gva-multihome-pods.yaml

Use Kubernetes node names exactly as returned by kubectl get nodes. In OKE clusters configured like the handoff, node names may be node private IPs.

Verification Commands

Use these checks after applying manifests:

kubectl -n kube-system get pods -l name=multus -o wide
kubectl -n gva-multihome-test get pods -o wide
kubectl -n gva-multihome-test get pod gva-multihome-a gva-multihome-b \
  -o jsonpath='{range .items[*]}{.metadata.name}{" on "}{.spec.nodeName}{"\n"}{.metadata.annotations.k8s\.v1\.cni\.cncf\.io/network-status}{"\n\n"}{end}'
kubectl -n gva-multihome-test exec gva-multihome-a -- ip -br addr
kubectl -n gva-multihome-test exec gva-multihome-b -- ip -br addr

Then ping net1 IPs across pods:

kubectl -n gva-multihome-test exec gva-multihome-a -- ping -c 3 -W 2 <pod-b-net1-ip>
kubectl -n gva-multihome-test exec gva-multihome-b -- ping -c 3 -W 2 <pod-a-net1-ip>

Troubleshooting

Read references/oke-multihome-notes.md when:

• Multus pods are missing or failing.
• Pods are stuck creating sandbox/network.
• ipvlan is missing on the host.
• OCI IPAM capacity or allocation behavior is unclear.
• Floating IP/VIP behavior is being explored.

Read references/oke-dpdk-mlx5-notes.md when:

• The workload uses DPDK, SR-IOV device-plugin resources, Mellanox/NVIDIA VFs, mlx5, vfio-pci, hugepages, or /dev/infiniband.
• A pod requests Multus networks and device-plugin resources but network-status only shows eth0.
• You need to decide whether the issue is Multus/NAD attachment, resource allocation, driver binding, RDMA/verbs exposure, hugepages, or app PCI/interface mapping.

For node-side inspection, prefer a privileged diagnostic DaemonSet that mounts / at /host and runs commands with chroot /host, rather than SSHing to each worker.

Sources

• https://docs.oracle.com/en-us/iaas/Content/ContEng/Tasks/contengAttaching_Multiple_VNICs.htm
• https://docs.oracle.com/en-us/iaas/Content/ContEng/Concepts/contengpodnetworking_topic-OCI_CNI_plugin.htm
• https://github.com/k8snetworkplumbingwg/multus-cni
• https://github.com/k8snetworkplumbingwg/network-attachment-definition-client
• https://www.cni.dev/plugins/current/main/ipvlan/
• https://kubernetes.io/docs/tasks/debug/debug-cluster/kubectl-node-debug/