primary UDN interface on VMs example (Passt binding pluging)

configure-primary-udn-dev-preview.txt

# Overview
The following depict example manifests of two scenarios of communication between VMs connected via primay-UDN:
1. VMs under the same namespace
2. VMs under different namespaces

## Prerequisits
- CNV 4.17 cluster.
- oc tool

# Configuring priamry-UDN on a CNV cluster
1. Enable the OCP FGs needed in order to turn on the TechPreviewNoUpgrade flag.
```
oc patch FeatureGate cluster --type=json -p '[{"op": "add", "path": "/spec/featureSet", "value": "TechPreviewNoUpgrade"}]'
```

2. Set the HCO FGs needed in order to deploy the primary-UDN components by CNV.
```bash
oc patch hco -n openshift-cnv kubevirt-hyperconverged --type=json -p='[{"op":"replace","path":"/spec/featureGates/primaryUserDefinedNetworkBinding","value":true},{"op":"replace","path":"/spec/featureGates/deployKubevirtIpamController","value":true}]'
```

  2.1. check HCO FGs enabled
```
oc get hco kubevirt-hyperconverged -n openshift-cnv -ojson | jq .spec.featureGates
```
  2.2. check kubevirt CR has the correct binding FG
```
oc get kv kubevirt-kubevirt-hyperconverged -n openshift-cnv -ojson | jq .spec.configuration.developerConfiguration.featureGates | grep NetworkBindingPlugins
```
  2.3 check passt network-binding correctly intalled on kubevirt CR
```
oc get kv kubevirt-kubevirt-hyperconverged -n openshift-cnv -ojson | jq .spec.configuration.network.binding
```
  2.4 check primary-udn net-attach-def:
```
 oc get net-attach-def primary-udn-kubevirt-binding -n default -oyaml
```

demo-scenario-1

# demo scenario #1: 2 VMs on same namespace

1. Create a new namespace where the VMs will reside
```bash
oc create ns blue-ns
```

apply the user NAD to allow OVN-K to plumb the pods in the selected namespace
```bash
cat <<EOF | oc apply -f -
apiVersion: k8s.cni.cncf.io/v1
kind: NetworkAttachmentDefinition
metadata:
  name: access-tenant-blue
  namespace: blue-ns
spec:
  config: |2

    {
            "cniVersion": "0.3.0",
            "name": "tenantblue",
            "type": "ovn-k8s-cni-overlay",
            "topology":"layer2",
            "subnets": "10.100.0.0/16",
            "mtu": 1400,
            "netAttachDefName": "blue-ns/access-tenant-blue",
            "role": "primary"
    }
EOF
```

3. Create two VMs on the selected namespace
```bash
cat <<EOF | oc apply -f -
apiVersion: kubevirt.io/v1
kind: VirtualMachine
metadata:
  name: vm-a
  namespace: blue-ns
spec:
  running: true
  template:
    spec:
      domain:
        devices:
          disks:
          - disk:
              bus: virtio
            name: containerdisk
          - disk:
              bus: virtio
            name: cloudinitdisk
          interfaces:
          - name: passtnet
            binding:
              name: passt
          rng: {}
        resources:
          requests:
            memory: 2048M
      networks:
      - name: passtnet
        pod: {}
      terminationGracePeriodSeconds: 0
      volumes:
      - containerDisk:
          image: quay.io/kubevirt/fedora-with-test-tooling-container-disk:v1.1.0
        name: containerdisk
      - cloudInitNoCloud:
          networkData: |
            version: 2
            ethernets:
              eth0:
                dhcp4: true
        name: cloudinitdisk
---
apiVersion: kubevirt.io/v1
kind: VirtualMachine
metadata:
  name: vm-b
  namespace: blue-ns
spec:
  running: true
  template:
    spec:
      domain:
        devices:
          disks:
          - disk:
              bus: virtio
            name: containerdisk
          - disk:
              bus: virtio
            name: cloudinitdisk
          interfaces:
          - name: passtnet
            binding:
              name: passt
          rng: {}
        resources:
          requests:
            memory: 2048M
      networks:
      - name: passtnet
        pod: {}
      terminationGracePeriodSeconds: 0
      volumes:
      - containerDisk:
          image: quay.io/kubevirt/fedora-with-test-tooling-container-disk:v1.1.0
        name: containerdisk
      - cloudInitNoCloud:
          networkData: |
            version: 2
            ethernets:
              eth0:
                dhcp4: true
        name: cloudinitdisk
EOF
```

4. Ping opposite VM from guest.
```
virtctl console <vm-a>
<login>
...
(ip -o -4 addr list eth0 | awk '{print $4}' | cut -d/ -f1 #vma-ip

virtctl console <vm-b>
<login>
...
(ip -o -4 addr list eth0 | awk '{print $4}' | cut -d/ -f1 #vmb-ip

virtctl console <vm-a>
ping <vmb-ip>
```

demo-scenario-2

# demo scenario #2: 2 VMs on different namespaces

1. Create a new namespace where the VMs will reside
```bash
oc create ns red-ns
oc create ns yellow-ns
```

apply the user NAD to allow OVN-K to plumb the pods in the selected namespace
```bash
cat <<EOF | oc apply -f -
apiVersion: k8s.cni.cncf.io/v1
kind: NetworkAttachmentDefinition
metadata:
  name: access-tenant-red
  namespace: red-ns
spec:
  config: |2

    {
            "cniVersion": "0.3.0",
            "name": "orange-network",
            "type": "ovn-k8s-cni-overlay",
            "topology":"layer2",
            "subnets": "10.101.0.0/16",
            "mtu": 1400,
            "netAttachDefName": "red-ns/access-tenant-red",
            "role": "primary"
    }
---
apiVersion: k8s.cni.cncf.io/v1
kind: NetworkAttachmentDefinition
metadata:
  name: access-tenant-yellow
  namespace: yellow-ns
spec:
  config: |2

    {
            "cniVersion": "0.3.0",
            "name": "orange-network",
            "type": "ovn-k8s-cni-overlay",
            "topology":"layer2",
            "subnets": "10.101.0.0/16",
            "mtu": 1400,
            "netAttachDefName": "yellow-ns/access-tenant-yellow",
            "role": "primary"
    }
EOF
```

3. Create two VMs on the selected namespace
```bash
cat <<EOF | oc apply -f -
apiVersion: kubevirt.io/v1
kind: VirtualMachine
metadata:
  name: vm-a
  namespace: red-ns
spec:
  running: true
  template:
    spec:
      domain:
        devices:
          disks:
          - disk:
              bus: virtio
            name: containerdisk
          - disk:
              bus: virtio
            name: cloudinitdisk
          interfaces:
          - name: passtnet
            binding:
              name: passt
          rng: {}
        resources:
          requests:
            memory: 2048M
      networks:
      - name: passtnet
        pod: {}
      terminationGracePeriodSeconds: 0
      volumes:
      - containerDisk:
          image: quay.io/kubevirt/fedora-with-test-tooling-container-disk:v1.1.0
        name: containerdisk
      - cloudInitNoCloud:
          networkData: |
            version: 2
            ethernets:
              eth0:
                dhcp4: true
        name: cloudinitdisk
---
apiVersion: kubevirt.io/v1
kind: VirtualMachine
metadata:
  name: vm-b
  namespace: yellow-ns
spec:
  running: true
  template:
    spec:
      domain:
        devices:
          disks:
          - disk:
              bus: virtio
            name: containerdisk
          - disk:
              bus: virtio
            name: cloudinitdisk
          interfaces:
          - name: passtnet
            binding:
              name: passt
          rng: {}
        resources:
          requests:
            memory: 2048M
      networks:
      - name: passtnet
        pod: {}
      terminationGracePeriodSeconds: 0
      volumes:
      - containerDisk:
          image: quay.io/kubevirt/fedora-with-test-tooling-container-disk:v1.1.0
        name: containerdisk
      - cloudInitNoCloud:
          networkData: |
            version: 2
            ethernets:
              eth0:
                dhcp4: true
        name: cloudinitdisk
EOF
```

4. Ping opposite VM from guest.
```
virtctl console <vm-a> -n red-ns
<login>
...
(ip -o -4 addr list eth0 | awk '{print $4}' | cut -d/ -f1 #vma-ip

virtctl console <vm-b> -n yellow-ns
<login>
...
(ip -o -4 addr list eth0 | awk '{print $4}' | cut -d/ -f1 #vmb-ip

virtctl console <vm-a> -n red-ns
ping <vmb-ip>
```

Maybe we should have one that use UserDefinedNetwork because different teams might look on this gist
and UserDefinedNetwork is more formal

For passt since it was removed from OVN

cat <<EOF | run_kubectl apply -f -
apiVersion: "k8s.cni.cncf.io/v1"
kind: NetworkAttachmentDefinition
metadata:
  name: primary-udn-kubevirt-binding
  namespace: default
spec:
  config: '{
  "cniVersion": "1.0.0",
  "name": "primary-udn-kubevirt-binding",
  "plugins": [
    {
      "type": "kubevirt-passt-binding"
    }
  ]
}'
EOF

need

  labels:
    k8s.ovn.org/primary-user-defined-network: ""

on ns where the primary nad is created (blue-ns etc)