Using the default Pod network with container-native virtualization - Container-native virtualization <strong>user</strong>'s guide | Container-native virtualization

Configuring masquerade mode from the command line
Selecting binding method
- Networking fields
Virtual machine configuration examples for the default network
- Template: virtual machine configuration file
- Template: Windows virtual machine instance configuration file

You can use the default Pod network with container-native virtualization. To do so, you must use the masquerade binding method. It is the only recommended binding method for use with the default Pod network. Do not use masquerade mode with non-default networks.

For secondary networks, use the bridge binding method.

Configuring masquerade mode from the command line

You can use masquerade mode to hide a virtual machine’s outgoing traffic behind the Pod IP address. Masquerade mode uses Network Address Translation (NAT) to connect virtual machines to the Pod network backend through a Linux bridge.

Enable masquerade mode and allow traffic to enter the virtual machine by editing your virtual machine configuration file.

Prerequisites

The virtual machine must be configured to use DHCP to acquire IPv4 addresses. The examples below are configured to use DHCP.

Procedure

Edit the interfaces spec of your virtual machine configuration file:

kind: VirtualMachine
spec:
  domain:
    devices:
      interfaces:
        - name: red
          masquerade: {} (1)
          ports:
            - port: 80 (2)
  networks:
  - name: red
    pod: {}

1	Connect using masquerade mode
2	Allow incoming traffic on port 80

Create the virtual machine:
```
$ oc create -f <vm-name>.yaml
```

Selecting binding method

If you create a virtual machine from the container-native virtualization web console wizard, select the required binding method from the Networking screen.

Networking fields

Name Description

Name	Description
Create NIC	Create a new NIC for the virtual machine.
NIC NAME	Name for the NIC.
MAC ADDRESS	MAC address for the network interface. If a MAC address is not specified, an ephemeral address is generated for the session.
NETWORK CONFIGURATION	List of available NetworkAttachmentDefinition objects.
BINDING METHOD	List of available binding methods. For the default Pod network, `masquerade` is the only recommended binding method. For secondary networks, use the `bridge` binding method. The `masquerade` method is not supported for non-default networks.
PXE NIC	List of PXE-capable networks. Only visible if `PXE` has been selected as the `Provision Source`.

Create NIC

Create a new NIC for the virtual machine.

NIC NAME

Name for the NIC.

MAC ADDRESS

MAC address for the network interface. If a MAC address is not specified, an ephemeral address is generated for the session.

NETWORK CONFIGURATION

List of available NetworkAttachmentDefinition objects.

BINDING METHOD

List of available binding methods. For the default Pod network, masquerade is the only recommended binding method. For secondary networks, use the bridge binding method. The masquerade method is not supported for non-default networks.

PXE NIC

List of PXE-capable networks. Only visible if PXE has been selected as the Provision Source.

Virtual machine configuration examples for the default network

Template: virtual machine configuration file

apiVersion: kubevirt.io/v1alpha3
kind: VirtualMachine
metadata:
  name: example-vm
  namespace: default
spec:
  running: false
  template:
    spec:
      domain:
        devices:
          disks:
            - name: containerdisk
              disk:
                bus: virtio
            - name: cloudinitdisk
              disk:
                bus: virtio
          interfaces:
          - masquerade: {}
            name: default
        resources:
          requests:
            memory: 1024M
      networks:
        - name: default
          pod: {}
      volumes:
        - name: containerdisk
          containerDisk:
            image: kubevirt/fedora-cloud-container-disk-demo
        - name: cloudinitdisk
          cloudInitNoCloud:
            userData: |
              #!/bin/bash
              echo "fedora" | passwd fedora --stdin

Template: Windows virtual machine instance configuration file

apiVersion: kubevirt.io/v1alpha3
kind: VirtualMachineInstance
metadata:
  labels:
    special: vmi-windows
  name: vmi-windows
spec:
  domain:
    clock:
      timer:
        hpet:
          present: false
        hyperv: {}
        pit:
          tickPolicy: delay
        rtc:
          tickPolicy: catchup
      utc: {}
    cpu:
      cores: 2
    devices:
      disks:
      - disk:
          bus: sata
        name: pvcdisk
      interfaces:
      - masquerade: {}
        model: e1000
        name: default
    features:
      acpi: {}
      apic: {}
      hyperv:
        relaxed: {}
        spinlocks:
          spinlocks: 8191
        vapic: {}
    firmware:
      uuid: 5d307ca9-b3ef-428c-8861-06e72d69f223
    machine:
      type: q35
    resources:
      requests:
        memory: 2Gi
  networks:
  - name: default
    pod: {}
  terminationGracePeriodSeconds: 0
  volumes:
  - name: pvcdisk
    persistentVolumeClaim:
      claimName: disk-windows

Using the default Pod network for virtual machines