2.4. Migrating a MicroShift cluster to IPv6 dual-stack networking

Procedure

1. If you have not done so, make a copy of the provided config.yaml.default file in the /etc/microshift/ directory, renaming it config.yaml.

2. Keep the new MicroShift config.yaml in the /etc/microshift/ directory. Your config.yaml file is read every time the MicroShift service starts.

   注意

   After you create it, the config.yaml file takes precedence over built-in settings.

3. Add IPv6 configurations to the network section of the MicroShift YAML with your valid values:

   警告

   You must keep the same first entry across restarts and migrations. This is true for any migration: single-to-dual stack, or dual-to-single stack. A complete wipe of the etcd database is required if a change to the first entry is needed. This might result in application data loss and is not supported.

   1. Add an IPv6 configuration for a second network in the network section of the MicroShift YAML with your valid values.

   2. Add network assignments to the network section of the MicroShift config.yaml to enable dual stack with IPv6 as secondary network.

      Example dual-stack IPv6 configuration with network assignments

      # ...
      apiServer:
        subjectAltNames:
        - 192.168.113.117
        - 2001:db9:ca7:ff::1db8 

      1

      
      network:
        clusterNetwork:
        - 10.42.0.0/16 

      2

      
        - fd01::/48 

      3

      
        serviceNetwork:
        - 10.43.0.0/16
        - fd02::/112 

      4

      
      node:
        nodeIP: 192.168.113.117 

      5

      
        nodeIPv6: 2001:db9:ca7:ff::1db8 

      6

      
      # ...

      1

      The IPv6 node address.

      2

      IPv4 network. Specify a clusterNetwork with a CIDR value that is less than 24.

      3

      IPv6 network. Specify a clusterNetwork with a CIDR value that is less than 64.

      4

      Specify an IPv6 CIDR with a prefix of 112. Kubernetes uses only the lowest 16 bits. For a prefix of 112, IP addresses are assigned from 112 to 128 bits.

      5

      Example node IP address. Maintain the previous IPv4 IP address.

      6

      Example node IP address. Must be an IPv6 address family.

4. Complete any other configurations you require, then restart MicroShift by running the following command:

   $ sudo systemctl restart microshift

5. Reset the IP family policy for application pods and services as needed, then restart those application pods and services to enable dual-stack networking. See "Resetting the IP family policy for application pods and services" for a simple example.

1. Retrieve the status of the pods by running the following command:

   $ oc get pod -A -o wide

   Example output

   NAMESPACE                  NAME                                      READY   STATUS    RESTARTS        AGE     IP                NODE           NOMINATED NODE   READINESS GATES
   kube-system                csi-snapshot-controller-bb7cb654b-7s5ql   1/1     Running   0               46m     10.42.0.6         microshift-9   <none>           <none>
   kube-system                csi-snapshot-webhook-95f475949-jrqv8      1/1     Running   0               46m     10.42.0.4         microshift-9   <none>           <none>
   openshift-dns              dns-default-zxkqn                         2/2     Running   0               46m     10.42.0.5         microshift-9   <none>           <none>
   openshift-dns              node-resolver-r2h5z                       1/1     Running   0               46m     192.168.113.117   microshift-9   <none>           <none>
   openshift-ingress          router-default-5b75594b4-228z7            1/1     Running   0               2m5s    10.42.0.3         microshift-9   <none>           <none>
   openshift-ovn-kubernetes   ovnkube-master-bltk7                      4/4     Running   2 (2m32s ago)   2m36s   192.168.113.117   microshift-9   <none>           <none>
   openshift-ovn-kubernetes   ovnkube-node-9ghgs                        1/1     Running   2 (2m32s ago)   46m     192.168.113.117   microshift-9   <none>           <none>
   openshift-service-ca       service-ca-5d7bd9db6-qgwgw                1/1     Running   0               46m     10.42.0.7         microshift-9   <none>           <none>
   openshift-storage          lvms-operator-656cd9b59b-8rpf4            1/1     Running   0               46m     10.42.0.8         microshift-9   <none>           <none>
   openshift-storage          vg-manager-wqmh4                          1/1     Running   2 (2m39s ago)   46m     10.42.0.10        microshift-9   <none>           <none>

2. Retrieve the networks defined by the OVN-K network plugin by running the following command:

   $ oc get pod -n openshift-ovn-kubernetes ovnkube-master-bltk7 -o jsonpath='{.status.podIPs}'

   Example output

   [{"ip":"192.168.113.117"},{"ip":"2001:db9:ca7:ff::1db8"}]

3. Retrieve the networks defined in the node resource by running the following command:

   $ oc get pod -n openshift-ingress router-default-5b75594b4-228z7 -o jsonpath='{.status.podIPs}'

   Example output

   [{"ip":"10.42.0.3"},{"ip":"fd01:0:0:1::3"}]