$ oc annotate namespace <namespace> \
k8s.ovn.org/multicast-enabled=true
With IP multicast, data is broadcast to many IP addresses simultaneously.
|
Multicast traffic between Red Hat OpenShift Service on AWS pods is disabled by default. If you are using the OVN-Kubernetes network plugin, you can enable multicast on a per-project basis.
You can enable multicast between pods for your project.
Install the OpenShift CLI (oc
).
You must log in to the cluster with a user that has the cluster-admin
or the dedicated-admin
role.
Run the following command to enable multicast for a project. Replace <namespace>
with the namespace for the project you want to enable multicast for.
$ oc annotate namespace <namespace> \
k8s.ovn.org/multicast-enabled=true
You can alternatively apply the following YAML to add the annotation:
|
To verify that multicast is enabled for a project, complete the following procedure:
Change your current project to the project that you enabled multicast for. Replace <project>
with the project name.
$ oc project <project>
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
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
In a new terminal window or tab, start the multicast listener.
Get the IP address for the Pod:
$ POD_IP=$(oc get pods mlistener -o jsonpath='{.status.podIP}')
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
Start the multicast transmitter.
Get the pod network IP address range:
$ CIDR=$(oc get Network.config.openshift.io cluster \
-o jsonpath='{.status.clusterNetwork[0].cidr}')
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"
If multicast is working, the previous command returns the following output:
mlistener