OVN-Kubernetes network plugin

Procedure

1. Create a JSON file with the following content:

   {
     "type": "sdnToOvn"
   }

   Copy to Clipboard Toggle word wrap

   • Optional: Within the JSON file, you can configure internal subnets using any or all of the options join, masquerade, and transit, along with a single CIDR per option, as shown in the following example:

     {
       "type": "sdnToOvn",
       "sdn_to_ovn": {
         "transit_ipv4": "192.168.255.0/24",
         "join_ipv4": "192.168.255.0/24",
         "masquerade_ipv4": "192.168.255.0/24"
       }
     }

     Copy to Clipboard Toggle word wrap
     Note

     OVN-Kubernetes reserves the following IP address ranges:

     100.64.0.0/16. This IP address range is used for the internalJoinSubnet parameter of OVN-Kubernetes by default.

     100.88.0.0/16. This IP address range is used for the internalTransSwitchSubnet parameter of OVN-Kubernetes by default.

     If these IP addresses have been used by OpenShift SDN or any external networks that might communicate with this cluster, you must patch them to use a different IP address range before initiating the limited live migration. For more information, see Patching OVN-Kubernetes address ranges in the Additional resources section.

2. To initiate the migration, run the following post request in a terminal window:

   $ ocm post /api/clusters_mgmt/v1/clusters/{cluster_id}/migrations 

   1

   
     --body=myjsonfile.json 

   2

   Copy to Clipboard Toggle word wrap

   1

   Replace {cluster_id} with the ID of the cluster you want to migrate to the OVN-Kubernetes network plugin.

   2

   Replace myjsonfile.json with the name of the JSON file you created in the previous step.

   Example output

   {
     "kind": "ClusterMigration",
     "href": "/api/clusters_mgmt/v1/clusters/2gnts65ra30sclb114p8qdc26g5c8o3e/migrations/2gois8j244rs0qrfu9ti2o790jssgh9i",
     "id": "7sois8j244rs0qrhu9ti2o790jssgh9i",
     "cluster_id": "2gnts65ra30sclb114p8qdc26g5c8o3e",
     "type": "sdnToOvn",
     "state": {
       "value": "scheduled",
       "description": ""
     },
     "sdn_to_ovn": {
       "transit_ipv4": "100.65.0.0/16",
       "join_ipv4": "100.66.0.0/16"
     },
     "creation_timestamp": "2025-02-05T14:56:34.878467542Z",
     "updated_timestamp": "2025-02-05T14:56:34.878467542Z"
   }

   Copy to Clipboard Toggle word wrap

Procedure

1. Navigate to OpenShift Cluster Manager and select your cluster.
2. Under the Virtual Private Cloud (VPC) section on the Networking page, click Edit cluster-wide proxy.

3. On the Edit cluster-wide proxy page, provide your proxy configuration details:

   1. Enter a value in at least one of the following fields:

      • Specify a valid HTTP proxy URL.
      • Specify a valid HTTPS proxy URL.

      • In the Additional trust bundle field, provide a PEM encoded X.509 certificate bundle.

        If you are replacing an existing trust bundle file, select Replace file to view the field. The bundle is added to the trusted certificate store for the cluster nodes. An additional trust bundle file is required if you use a TLS-inspecting proxy unless the identity certificate for the proxy is signed by an authority from the Red Hat Enterprise Linux CoreOS (RHCOS) trust bundle. This requirement applies regardless of whether the proxy is transparent or requires explicit configuration using the http-proxy and https-proxy arguments.

   2. Click Confirm.

1. Change your current project to the project that you enabled multicast for. Replace <project> with the project name.

   $ oc project <project>

   Copy to Clipboard Toggle word wrap

2. Create a pod to act as a multicast receiver:

   $ cat <<EOF| oc create -f -
   apiVersion: v1
   kind: Pod
   metadata:
     name: mlistener
     labels:
       app: multicast-verify
   spec:
     containers:
       - name: mlistener
         image: registry.access.redhat.com/ubi9
         command: ["/bin/sh", "-c"]
         args:
           ["dnf -y install socat hostname && sleep inf"]
         ports:
           - containerPort: 30102
             name: mlistener
             protocol: UDP
   EOF

   Copy to Clipboard Toggle word wrap

3. Create a pod to act as a multicast sender:

   $ cat <<EOF| oc create -f -
   apiVersion: v1
   kind: Pod
   metadata:
     name: msender
     labels:
       app: multicast-verify
   spec:
     containers:
       - name: msender
         image: registry.access.redhat.com/ubi9
         command: ["/bin/sh", "-c"]
         args:
           ["dnf -y install socat && sleep inf"]
   EOF

   Copy to Clipboard Toggle word wrap

4. In a new terminal window or tab, start the multicast listener.

   1. Get the IP address for the Pod:

      $ POD_IP=$(oc get pods mlistener -o jsonpath='{.status.podIP}')

      Copy to Clipboard Toggle word wrap

   2. Start the multicast listener by entering the following command:

      $ oc exec mlistener -i -t -- \
          socat UDP4-RECVFROM:30102,ip-add-membership=224.1.0.1:$POD_IP,fork EXEC:hostname

      Copy to Clipboard Toggle word wrap

5. Start the multicast transmitter.

   1. Get the pod network IP address range:

      $ CIDR=$(oc get Network.config.openshift.io cluster \
          -o jsonpath='{.status.clusterNetwork[0].cidr}')

      Copy to Clipboard Toggle word wrap

   2. To send a multicast message, enter the following command:

      $ oc exec msender -i -t -- \
          /bin/bash -c "echo | socat STDIO UDP4-DATAGRAM:224.1.0.1:30102,range=$CIDR,ip-multicast-ttl=64"

      Copy to Clipboard Toggle word wrap

      If multicast is working, the previous command returns the following output:

      mlistener

      Copy to Clipboard Toggle word wrap