Booting a VM of an iSCSI LUN - inside a Kubernetes cluster

Create some entities in Kubernetes:

# Create the pod, services, persistent volumes, and claims
$ kubectl create -f iscsi-demo-target-tgtd.yaml
persistentvolumeclaim "disk-custom" created
persistentvolumeclaim "disk-alpine" created
persistentvolumeclaim "disk-cirros" created
persistentvolume "iscsi-disk-custom" created
persistentvolume "iscsi-disk-alpine" created
persistentvolume "iscsi-disk-cirros" created
service "iscsi-demo-target" created
pod "iscsi-demo-target-tgtd" created

Now use a pod to access the created target:

# Run a qemu instance to see if the target can be used
# Note: This is not testing the PV or PVC, just the service and     target
# Use ctrl-a c quit to quit
$ kubectl run --rm -it qemu-test --image=kubevirt/libvirtd -- \
  qemu-system-x86_64 \
    -snapshot \
    -drive file=iscsi://iscsi-demo-target/iqn.2017-01.io.kubevirt:sn.42/2 \
    -nographic

And enjoy the boot:

ISOLINUX 6.04 6.04-pre1  Copyright (C) 1994-2015 H. Peter Anvin et al
boot: 


OpenRC 0.21.7.818fc79999 is starting up Linux 4.4.45-0-virtgrsec (x86_64)
…
Welcome to Alpine Linux 3.5
Kernel 4.4.45-0-virtgrsec on an x86_64 (/dev/ttyS0)

localhost login:

Okay - It’s not all end-to-end yet - when looking at it from a KubeVirt perspective.

What you see is that a qemu instance is booting of an iSCSI target LUN, offered by an iSCSI portal running as an unprivileged pod on a Kubernetes cluster.

But that’s already nice, what was achieved so far:

iSCSI target pod with demo content
Service, volumes, claims to expose the content
qemu can boot from the LUN
VM object can be created to boot of the LUN (if you specify the LUN)

The remaining gap (which is being worked on) is to allow specifying a claim in the VM object (instead of the LUN as we did it above). And then we can use KubeVirt to boot a VM of a disk image - probably.

::: {#footer} [ February 28th, 2017 10:38pm ]{#timestamp} [kubernetes]{.tag} [kubevirt]{.tag} [qemu]{.tag} [libvirtd]{.tag} [fedora]{.tag} [iscsi]{.tag} :::