Using KubeVirt to bring virtual machine workloads to Kubernetes and what it means for OpenStack

1. KubeWHAT!?
Using KubeVirt to bring virtual machines to
Kubernetes and what it means for OpenStack
Stephen Gordon (@xsgordon)
October 19th, 2017

2. KUBEWHAT!? - OPENSTACK DAY CANADA 2017
DISCLAIMER
This is not a product pitch, this is R&D.
There be dragons!

3. KUBEWHAT!? - OPENSTACK DAY CANADA 2017
WHAT IS KUBEVIRT?
Add-on that extends Kubernetes to support scheduling of VM workloads
alongside container workloads.
https://github.com/kubevirt

4. KUBEWHAT!? - OPENSTACK DAY CANADA 2017
WHAT IS KUBEVIRT?
● Drops directly into existing Kubernetes Clusters
○ No additional host setup
○ Simple Install
○ Extends kubernetes so VMs can be scheduled alongside Containers
● Ties VMs into Pod Network
● Integrates with other Kubernetes concepts (like Persistent Volumes)
● Manage VMs like Pods

5. KUBEWHAT!? - OPENSTACK DAY CANADA 2017
KUBEVIRT IS NOT A CRI IMPLEMENTATION!
● Hypervisor CRI
○ Pod specification is the API
● KubeVirt:
○ Dedicated API
■ Virtual devices
■ Live migration
■ More VM specific needs in the future...
CRI = Container Runtime Interface

6. KUBEWHAT!? - OPENSTACK DAY CANADA 2017
KUBEVIRT IS NOT A CRI IMPLEMENTATION!

7. KUBEWHAT!? - OPENSTACK DAY CANADA 2017
WHY?
● Migration Path
○ People invested in VMs can migrate to containers and bring VMs with them
● VM Scheduler Convergence
○ OpenStack, oVirt, others, can potentially converge on a common scheduler
● Container Workload Isolation
○ Running untrusted container workloads in a hypervisor
● Infrastructure convergence
○ Moves towards unified infrastructure capable of scheduling all workloads

8. LET’S POKE IT

9. KUBEWHAT!? - OPENSTACK DAY CANADA 2017
DEMO
Pre-requisites:
● kubectl
● minikube
$ minikube start --vm-driver kvm --network-plugin cni
$ git clone https://github.com/kubevirt/demo.git
$ cd demo
$ ./run-demo.sh

10. KUBEWHAT!? - OPENSTACK DAY CANADA 2017
DEMO (cont.)
● Review what the demo script does.
● Dive into each pod’s contents with focus on:
○ Where our storage comes from.
○ Where the VMs run.
○ The VM pod!
● Consoles and SPICE
● Launch a second VM.

11. KUBEWHAT!? - OPENSTACK DAY CANADA 2017
TYPICAL WORKFLOW
kind: VirtualMachine
metadata:
name: testvm
spec:
domain:
devices:
graphics:
- type: spice
consoles:
- type: pty
In case of ERR_DEMO_NO_WORKIE
Typical Pod commands:
● kubectl create -f mypodspec.yaml
● kubectl delete mypod
● kubectl exec mypod -it /bin/bash
Typical VirtualMachine commands:
● kubectl create -f myvmspec.yaml
● kubectl delete testvm
● kubectl plugin virt console testvm
● kubectl plugin virt spice testvm

12. WHERE DOES OPENSTACK FIT?

13. KUBEWHAT!? - OPENSTACK DAY CANADA 2017
WHERE DOES OPENSTACK FIT?
● Infrastructure provisioning capabilities and back-end ecosystem:
○ Bare-metal
○ Networking
○ Storage
● Standardized APIs and management/operational ecosystem:
○ Clients
○ Orchestrators
○ Cloud Management Platforms

14. KUBEWHAT!? - OPENSTACK DAY CANADA 2017
WHAT IS DICOT?
Building a path towards using KubeVirt to manage virtual machines while
supporting existing user investments in OpenStack APIs.
https://dicot-project.github.io/about

15. KUBEWHAT!? - OPENSTACK DAY CANADA 2017
POTENTIAL APPROACHES
● Nova virt driver for KubeVirt
○ Simplest option evaluated.
○ Similar to approach of Nova vCenter driver, single Nova instance is in fact a cluster.
○ Limits convergence opportunities somewhat.
● OpenStack compatible API for KubeVirt
○ Fuller convergence model, esp. in terms of base requirements.
○ Potential long “string” of APIs required beyond core to run VMs.
○ Potential to still use full OpenStack services as backends where supported (e.g. volumes,
networks, etc.)
● Other approaches considered but discarded incl. via Cell, direct RPC.

16. KUBEWHAT!? - OPENSTACK DAY CANADA 2017
DIAGRAM: NOVA VIRT DRIVER FOR
KUBEVIRT

17. KUBEWHAT!? - OPENSTACK DAY CANADA 2017
DIAGRAM: OPENSTACK COMPATIBLE API

18. KUBEWHAT!? - OPENSTACK DAY CANADA 2017
INTERESTED IN COLLABORATING?
Join us in the Virtualized Workloads Saloon at KubeCon NA in Austin TX!
KubeVirt
● GitHub:
○ https://github.com/kubevirt/kubevirt
● Mailing List:
○ https://groups.google.com/forum/#!forum/kubevirt-dev
● IRC:
○ #kubevirt on irc.freenode.net
Dicot
● GitHub:
○ https://github.com/dicot-project/
Slides will be posted, look for a link from @xsgordon on Twitter.

19. THANK YOU
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facebook.com/redhatinc
twitter.com/RedHatNews