- It is a contact between the container runtime and other plugins, and it doesn't have any of its own net configuration, it calls other plugins like flannel/calico to do the real net conf job.
- Multus reuses the concept of invoking the delegates in flannel, it groups the multi plugins into delegates and invoke each other in sequential order, according to the JSON scheme in the cni configuration.
Make sure that the multus, [sriov](https://github.com/Intel-Corp/sriov-cni), [flannel](https://github.com/containernetworking/cni/blob/master/Documentation/flannel.md), and [ptp](https://github.com/containernetworking/cni/blob/master/Documentation/ptp.md) binaries are in the `/opt/cni/bin` directories and follow the steps as mention in the [CNI](https://github.com/containernetworking/cni/#running-a-docker-container-with-network-namespace-set-up-by-cni-plugins)
## Testing the Multus CNI with Kubernetes
Refer the Kubernetes User Guide and network plugin
Kubelet must be configured to run with the CNI `--network-plugin`, with the following configuration information.
Edit `/etc/default/kubelet` file and add `KUBELET_OPTS`:
```
KUBELET_OPTS="...
--network-plugin-dir=/etc/cni/net.d
--network-plugin=cni
"
```
Restart the kubelet
```
# systemctl restart kubelet.service
```
### Launching workloads in Kubernetes
Launch the workload using yaml file in the kubernetes master, with above configuration in the multus CNI, each pod should have multiple interfaces.
> Note: To verify whether Multus CNI plugin is working fine create a pod containing one “busybox” container and execute “ip link” command to check if interfaces management follows configuration.
1. Create “multus-test.yaml” file containing below configuration. Created pod will consist of one “busybox” container running “top” command.
```
apiVersion: v1
kind: Pod
metadata:
name: multus-test
spec: # specification of the pod's contents
restartPolicy: Never
containers:
- name: test1
image: "busybox"
command: ["top"]
stdin: true
tty: true
```
2. Create pod using command:
```
# kubectl create -f multus-test.yaml
pod "multus-test" created
```
3. Run “ip link” command inside the container:
```
# 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1
