manually configure ipv6 addresses and route on ipv4 OCP cluster to create a dualstack cluster, newly created pods will stay in 'ContainerCreating' status

4.12

1. enable ipv6 in network.
# more patch_dual.yaml 
- op: add
  path: /spec/clusterNetwork/-
  value:
    cidr: fd01::/48
    hostPrefix: 64
- op: add
  path: /spec/serviceNetwork/-
  value: fd02::/112
# oc patch network.config.openshift.io cluster --type='json' --patch-file patch_dual.yaml
 
2. Configure ipv6 addresses and routes

PODS=$(oc get pods -n openshift-cluster-node-tuning-operator -l openshift-app=tuned --field-selector=status.phase=Running --no-headers -o name)
i=10
for pod in $PODS; do
  oc exec -n openshift-cluster-node-tuning-operator $pod -- ip -6 addr add fd00:172:22::${i}/64 dev br-ex
  oc exec -n openshift-cluster-node-tuning-operator $pod -- ip -6 route add default via fd00:172:22::1 dev br-ex
  ((i=i+1))
done 

3. create pods and they will stay in ContainerCreating status.

4. if remove the ipv6 configuration in network, newly created pods can be ready.

Pod can not be running

Pod should be ready with both ipv4 and ipv6 address.

version:
# oc version
Client Version: 4.12.0-0.nightly-2022-11-30-182550
Kustomize Version: v4.5.7
Server Version: 4.12.0-0.nightly-2022-11-30-182550
Kubernetes Version: v1.25.2+5533733

Describe pods:
# oc describe pod iperf-rc-normal-qg6zd 
Name:             iperf-rc-normal-qg6zd
Namespace:        offload-testing
Priority:         0
Service Account:  default
Node:             openshift-qe-025.lab.eng.rdu2.redhat.com/192.168.111.54
Start Time:       Thu, 01 Dec 2022 21:35:28 -0500
Labels:           name=iperf-pods-normal
Annotations:      k8s.ovn.org/pod-networks:
                    {"default":{"ip_addresses":["10.129.2.7/23","fd01:0:0:6::3/64"],"mac_address":"0a:58:0a:81:02:07","gateway_ips":["10.129.2.1","fd01:0:0:6:...
                  openshift.io/scc: restricted-v2
                  seccomp.security.alpha.kubernetes.io/pod: runtime/default
Status:           Pending
IP:               
IPs:              <none>
Controlled By:    ReplicationController/iperf-rc-normal
Containers:
  iperf:
    Container ID:   
    Image:          quay.io/openshifttest/iperf3@sha256:440c59251338e9fcf0a00d822878862038d3b2e2403c67c940c7781297953614
    Image ID:       
    Port:           <none>
    Host Port:      <none>
    State:          Waiting
      Reason:       ContainerCreating
    Ready:          False
    Restart Count:  0
    Limits:
      memory:  340Mi
    Requests:
      memory:     340Mi
    Environment:  <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-4266b (ro)
Conditions:
  Type              Status
  Initialized       True 
  Ready             False 
  ContainersReady   False 
  PodScheduled      True 
Volumes:
  kube-api-access-4266b:
    Type:                    Projected (a volume that contains injected data from multiple sources)
    TokenExpirationSeconds:  3607
    ConfigMapName:           kube-root-ca.crt
    ConfigMapOptional:       <nil>
    DownwardAPI:             true
    ConfigMapName:           openshift-service-ca.crt
    ConfigMapOptional:       <nil>
QoS Class:                   Burstable
Node-Selectors:              <none>
Tolerations:                 node.kubernetes.io/memory-pressure:NoSchedule op=Exists
                             node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
                             node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
  Type     Reason                  Age                     From     Message
  ----     ------                  ----                    ----     -------
  Warning  FailedCreatePodSandBox  3m4s (x173 over 5h50m)  kubelet  (combined from similar events): Failed to create pod sandbox: rpc error: code = Unknown desc = failed to create pod network sandbox k8s_iperf-rc-normal-qg6zd_offload-testing_18673f13-37b4-40ea-aa5d-85654dfa5c85_0(4899f7150492fa4cd895c62d0ec25ac5c1507016037c31b6019849083b42cdb5): error adding pod offload-testing_iperf-rc-normal-qg6zd to CNI network "multus-cni-network": plugin type="multus" name="multus-cni-network" failed (add): [offload-testing/iperf-rc-normal-qg6zd/18673f13-37b4-40ea-aa5d-85654dfa5c85:ovn-kubernetes]: error adding container to network "ovn-kubernetes": CNI request failed with status 400: '[offload-testing/iperf-rc-normal-qg6zd 4899f7150492fa4cd895c62d0ec25ac5c1507016037c31b6019849083b42cdb5] [offload-testing/iperf-rc-normal-qg6zd 4899f7150492fa4cd895c62d0ec25ac5c1507016037c31b6019849083b42cdb5] failed to configure pod interface: timed out waiting for OVS port binding (ovn-installed) for 0a:58:0a:81:02:07 [10.129.2.7/23 fd01:0:0:6::3/64]
'