docs/doc/source/kube-virt/hello-world-kubevirt-vm-05503659173c.rst

Hello World KubeVirt VM

This section provides a 'hello world' example of creating, running and attaching to a with KubeVirt. The example uses

• A CirrOS image packaged as a Container Image and available from docker.io:kubevirt/cirros-container-disk-demo:latest
• A 'containerDisk' volume type
  • The containerDisk feature provides the ability to store and distribute disks in a container image registry.
  • containerDisks can be assigned to in the disks section of the VirtualMachine spec.
  • containerDisks are ephemeral storage devices; so can they only be used by applications that do NOT require persistent data.
• A cloudInitNoCloud volume type, which allows attaching cloudInitNoCloud data-sources to the . If the contains a proper cloud-init setup, it will pick up the disk as a user-data source.
• No additional network interfaces other than the default interface of the container running the .
• Connect with either the serial console interface via virtctl, or through a NodePort service on the Floating OAM IP Address.

Complete the procedure below to create the , start the and login into the via the console:

1. Create the yaml file defining the VirtualMachine instance.

   $ cat <<EOF > vm-cirros-containerdisk.yaml
   apiVersion: kubevirt.io/v1alpha3
   kind: VirtualMachine
   metadata:
   labels:
     kubevirt.io/vm: vm-cirros
   name: vm-cirros
   spec:
   running: false template:
   metadata:
     labels:
       kubevirt.io/vm: vm-cirros
   spec:
     running: false
     template:
       metadata:
         labels:
           kubevirt.io/vm: vm-cirros 
       spec:
         domain:
           devices:
             disks:
             - disk:
                 bus: virtio
                name: containerdisk
             - disk:
                 bus: virtio
                name: cloudinitdisk
         machine:
           type: ""
         resources:
           requests:
             memory: 64M
       terminationGracePeriodSeconds: 0
       volumes:
       - name: containerdisk
         containerDisk:
           image: kubevirt/cirros-container-disk-demo:latest
       - cloudInitNoCloud:
           userDataBase64: IyEvYmluL3NoCgplY2hvICdwcmludGVkIGZyb20gY2xvdWQtaW5pdCB1c2VyZGF0YScK
         name: cloudinitdisk
   EOF

2. Apply the yaml file to create the in a stopped state.

   $ kubectl apply -f cdi-uploadproxy-nodeport-service.yaml virtualmachine.kubevirt.io/vm-cirros created
   
   $ kubectl get vm
   NAME      AGE STATUS  READY
   vm-cirros 17s Stopped False
   
   $ kubectl get vmi
   No resources found in default namespace.

3. Start the with the virtctl tool.

   $ virtctl start vm-cirros
   VM vm-cirros was scheduled to start
   
   $ kubectl get vm
   NAME         AGE  STATUS   READY
   vm-cirro     87s  Running  True
   
   $ kubectl get vmi
   NAME         AGE PHASE   IP               NODENAME    READY
   vm-cirros    17s Running 172.16.225.72    compute-2   True

4. Connect to and login into the console using the virtctl tool.

   $ virtctl console vm-cirros
   Successfully connected to vm-cirros console. The escape sequence is ^]
   
   # login as 'cirros' user. default password: 'gocubsgo'. Use 'sudo' for root. 
   # vm-cirros login: cirros
   Password:
   
   $ hostname vm-cirros
   
   $ ls /
     bin       home           lib64          mnt         root        tmp 
     boot      init           linuxrc        old-root    run         usr 
     dev       initrd.img     lost+found     opt         sbin        var
     etc       lib            media          proc        sys         vmlinuz
   
   $ ip link
   1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
   2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000 link/ether a6:77:37:4c:ee:10 brd ff:ff:ff:ff:ff:ff
   
   # List Interfaces
   # Notice how the VM has a single eth0 interface, the default CNI interface.
   
   $ ip addr
   1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo
   valid_lft forever preferred_lft forever inet6 ::1/128 scope host
   
   valid_lft forever preferred_lft forever
   2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000 link/ether a6:77:37:4c:ee:10 brd ff:ff:ff:ff:ff:ff
   inet 172.16.225.72/32 brd 172.16.255.255 scope global eth0
   valid_lft forever preferred_lft forever inet6 fe80::a477:37ff:fe4c:ee10/64 scope link valid_lft forever preferred_lft forever
   # Exit/escape from the VM Console with ctrl+']'
   $ ^]

5. Expose the SSH port of vm-cirros via a NodePort.

   $ virtctl expose vmi vm-cirros --port=22 --name vm-cirros-ssh --type=NodePort
   Service vm-cirros-ssh successfully exposed for vmi vm-cirros
   
   $ kubectl get service
   NAME            TYPE      CLUSTER-IP     EXTERNAL-IP PORT(S)       AGE
   kuard-nodeport NodePort   10.96.155.165 <none>       80:31118/TCP 92d
   kubernetes      ClusterIP 10.96.0.1      <none>       443/TCP       188d
   nodeinfo        ClusterIP 10.96.189.47   <none>       1080/TCP      92d
   vm-cirros-ssh   NodePort  10.99.91.228   <none>       22:31562/TCP 9s

6. Connect from a remote workstation.

   $ ssh -p 31562 cirros@<Floating-OAM-IP-Address-of-> password:

   $ hostname vm-cirros

   # List Interfaces # Notice how the VM has a single eth0 interface, the default CNI interface.

   $ ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000 link/ether a6:77:37:4c:ee:10 brd ff:ff:ff:ff:ff:ff inet 172.16.225.72/32 brd 172.16.255.255 scope global eth0 valid_lft forever preferred_lft forever inet6 fe80::a477:37ff:fe4c:ee10/64 scope link valid_lft forever preferred_lft forever

   $ exit