KubeVirt FQDN connectivity

README.md

KubeVirt FQDN connectivity

This example sets up two KubeVirt VMs connected to the cluster network via masquerade. These VMs can use their FQDN to access themselves locally and get from one to another over the cluster network.

Apply VMs and Services

kubectl apply -f vms.yaml

Wait for VMs to be running

kubectl wait vmi vm1 vm2 --for condition=Available

Connect to one of the VMs

virtctl console vm1  # login with fedora:fedora

Verify that FQDN of the VM can be resolved locally

sudo dnf install -y traceroute
traceroute vm1.default.svc.cluster.local

traceroute to vm1.default.svc.cluster.local (127.0.0.1), 30 hops max, 60 byte packets
 1  localhost (127.0.0.1)  0.542 ms  0.400 ms  0.375 ms

Verify that it is possible to reach out to the second VM using the service name

ssh fedora@vm2.default.svc.cluster.local

The authenticity of host 'vm2.default.svc.cluster.local (10.96.130.9)' can't be established.
ECDSA key fingerprint is SHA256:nyj164Cw67561g1d7kO9TthUZtMfVyfWwFzuHn0LNjM.
ECDSA key fingerprint is MD5:d3:10:16:ff:1a:79:48:73:13:e2:61:d3:18:ee:a1:df.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'vm2.default.svc.cluster.local,10.96.130.9' (ECDSA) to the list of known host
s.                                                                                                     
fedora@vm2.default.svc.cluster.local's password: 
[fedora@vm2 ~]$ 

vms.yaml

---
apiVersion: kubevirt.io/v1alpha3
kind: VirtualMachine
metadata:
  name: vm1
  labels:
    kubevirt.io/vm: vm1
spec:
  running: true
  template:
    metadata:
      labels:
        kubevirt.io/vm: vm1
    spec:
      domain:
        devices:
          interfaces:
          - name: default
            masquerade: {}
          disks:
          - disk:
              bus: virtio
            name: registryvolume
          - disk:
              bus: virtio
            name: cloudinitvolume
        resources:
          requests:
            memory: 512M
      networks:
      - name: default
        pod: {}
      volumes:
      - name: registryvolume
        containerDisk:
          image: kubevirt/fedora-cloud-registry-disk-demo:latest
      - cloudInitNoCloud:
          userData: |-
            #cloud-config
            password: fedora
            chpasswd: { expire: False }
            hostname: vm1
            fqdn: vm1.default.svc.cluster.local
            bootcmd:
            - echo 127.0.0.1 vm1.default.svc.cluster.local >> /etc/hosts
        name: cloudinitvolume
---
apiVersion: v1
kind: Service
metadata:
  name: vm1
spec:
  ports:
  - port: 22
    protocol: TCP
  selector:
    kubevirt.io/vm: vm1
  type: ClusterIP
---
apiVersion: kubevirt.io/v1alpha3
kind: VirtualMachine
metadata:
  name: vm2
spec:
  running: true
  template:
    metadata:
      labels:
        kubevirt.io/vm: vm2
    spec:
      domain:
        devices:
          interfaces:
          - name: default
            masquerade: {}
          disks:
          - disk:
              bus: virtio
            name: registryvolume
          - disk:
              bus: virtio
            name: cloudinitvolume
        resources:
          requests:
            memory: 512M
      networks:
      - name: default
        pod: {}
      volumes:
      - name: registryvolume
        containerDisk:
          image: kubevirt/fedora-cloud-registry-disk-demo:latest
      - cloudInitNoCloud:
          userData: |-
            #cloud-config
            password: fedora
            chpasswd: { expire: False }
            hostname: vm2
            fqdn: vm2.default.svc.cluster.local
            bootcmd:
            - echo 127.0.0.1 vm2.default.svc.cluster.local >> /etc/hosts
        name: cloudinitvolume
---
apiVersion: v1
kind: Service
metadata:
  name: vm2
spec:
  ports:
  - port: 22
    protocol: TCP
  selector:
    kubevirt.io/vm: vm2
  type: ClusterIP