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Remember when virtualization was the hot new thing? Twenty years ago, I was racking and deploying physical servers at a small hosting company when I had my first experience of virtualization.

Watching vMotion live-migrate workloads between physical hosts was an aha moment for me, and I knew virtualization would change the entire ecosystem.

Perhaps then its not a surprise that I became an architect at VMware for many years.

I had a similar aha moment a decade later with containers and Docker, seeing the breakthrough it represented for my dev colleagues. And in the years after it was clear that Kubernetes presented a natural extension of this paradigm shift.

Im sure many of you reading this will have been through similar awakenings.

Despite 20 years of innovation, reality has a way of bringing us back down to earth. Out in the enterprise, the fact is we have not completely transitioned to cloud native applications or cloud native infrastructure.

While containerized apps are gaining popularity, there are still millions of VM-based applications out there across the enterprise. A new technology wave doesnt always wipe out its predecessor.

It may be decades before every enterprise workload is refactored into containerized microservices. Some never will be: for example, if their code is too complex or too old.

So we have a very real question: How do we make virtualization and containers coexist within the enterprise?

We have a few options:

And indeed there is a solution to make this third option possible: KubeVirt.

KubeVirt is a Cloud Native Computing Foundation (CNCF) incubating project that, coincidentally, just hit version 1.0 last week.

Leveraging the fact that the kernel-based virtual machine (KVM) hypervisor is itself a Linux process that can be containerized, KubeVirt enables KVM-based virtual machine workloads to be managed as pods in Kubernetes.

This means that you can bring your VMs into a modern Kubernetes-based cloud native environment rather than doing an immediate refactoring of your applications.

KubeVirt brings K8s-style APIs and manifests to drive both the provisioning and management of virtual machines using simple resources, and provides standard VM operations (VM life cycle, power operations, clone, snapshot, etc.).

Users requiring virtualization services are speaking to the virtualization API (see the diagram below), which in turn is speaking to the Kubernetes cluster to schedule the requested virtual machine instances (VMIs).

Scheduling, networking and storage are all delegated to Kubernetes, while KubeVirt provides the virtualization functionality.

KubeVirt delivers three things to provide virtual machine management capabilities:

Because virtual machines run as pods in Kubernetes, they benefit from:

KubeVirt sounds amazing, doesnt it? You can treat your VMs like just another container.

Well, thats the end goal: getting there is another matter.

KubeVirt is open source, so you can download and install it today.

But the manual installation process can be time-consuming, and you may face challenges with integrating and ensuring compatibility with all the necessary components.

To start, you need a running Kubernetes cluster, on which you:

You need to do this for each cluster. While a basic installation allows you to create simple virtual machines, advanced features such as live migration, cloning or snapshots require you to deploy and configure additional components (snapshot controller, Containerized Data Importer, etc).

We mentioned above about the inefficiency of nested infrastructures. Although its technically possible to run KubeVirt nested on top of other VMs or public cloud instances, it requires software emulation, which has a performance impact on your workloads.

Instead, it makes a lot of sense to run KubeVirt on bare metal Kubernetes and that, traditionally, has not been easy. Standing up a bare metal server, deploying the operating system and managing it, deploying Kubernetes on top the process can be convoluted, especially at scale.

When it comes to Day 2 operations, KubeVirt leaves the user with a lot of manual heavy lifting. Lets look at a couple of examples:

First, KubeVirt doesnt come with a UI by default: its all command line interface (CLI) or API. This may be perfectly fine for cluster admins that are used to operating Kubernetes and containers, but it may be a challenging gap for virtualization admins that are used to operating from a graphical user interface (GUI).

Even an operation as simple as starting or stopping a virtual machine requires patching the VM manifest or using the virtctl command line.

Another example is live migration: To live migrate a VM to a different node, you have to create a VirtualMachineInstanceMigration resource that tells KubeVirt what to do.

apiVersion: kubevirt.io/v1kind: VirtualMachineInstanceMigrationmetadata: name: live-migrate-webapp01 namespace: defaultspec: vmiName: webapp01

apiVersion: kubevirt.io/v1

kind: VirtualMachineInstanceMigration

metadata:

name: live-migrate-webapp01

namespace: default

spec:

vmiName: webapp01

If youre running at scale, performing many such operations each day across multiple clusters, the effort can be considerable. Building out scripting or automation can solve that, but itself increases the learning curve and adds to the setup cost.

We saw an opportunity to take all the goodness that KubeVirt offers, address all these issues, and create a truly enterprise-grade solution for running VMs on Kubernetes.

And today weve announced just that: Meet Virtual Machine Orchestrator (VMO), new in version 4.0 of our Palette Kubernetes management platform.

VMO is a free capability that leverages KubeVirt and makes it easy to manage virtual machines (VMs) and Kubernetes containers together, from a single unified platform.

Here are the highlights.

If youre not familiar with Palette, one of the things that makes it unique is the concept of Cluster Profiles, preconfigured and repeatable blueprints that document every layer of the cluster stack, from the underlying OS to the apps on top, which you can deploy to a cluster with a few clicks.

Weve built an add-on pack for VMO that contains all the KubeVirt components we talked about earlier, and much much more, including:

Palette can not only build a cluster for you, but deploy the VM management capability preconfigured into that cluster thanks to the Cluster Profile. The result is much less manual configuration effort.

Whats more, Palettes multicluster decentralized architecture makes it easy to deliver the VMO capability easily to multiple clusters instead of having to enable it manually per cluster.

We talked about the importance of running KubeVirt on bare metal, and how hard it is to provision and manage bare metal servers for Kubernetes.

Well, Palette was built to simplify the way you deploy Kubernetes clusters in all kinds of environments, and bare metal is no exception.

There are many ways of orchestrating bare-metal servers, but one of the most popular ones is Canonical MAAS, which allows you to manage the provisioning and the life cycle of physical machines like a private cloud.

Were big fans of MAAS, and weve included Canonical MAAS and our MAAS Provider for Cluster API in our VMO pack to automate the deployment of the OS and Kubernetes on bare metal hardware. It makes deploying a new Kubernetes bare metal cluster as easy as cloud.

Of course, you can use your own bare metal provider if you dont want to use MAAS.

Once everything is up and running, Palettes always-on declarative management keeps the entire state of your cluster as designed, with automated reconciliation loops to eliminate configuration drift. This covers your VM workloads too.

While DIY KubeVirt leaves you on your own when it comes to some of the more powerful features youve come to expect in the world of virtualization, Palette provides a long list of capabilities out of the box.

These include VM live migration, dynamic resource rebalancing and maintenance mode for repairing or replacing host machines, and the ability to declare a new VLAN from the UI. You also get out-of-the-box monitoring of clusters, nodes and virtual machines using Prometheus and Grafana.

And while with DIY KubeVirt the platform operator (thats you) must select, install and configure one of the open source solutions to get a UI, Palette already looks like this:

As you can tell, were pretty excited about the launch of Palette 4.0 and the Virtual Machine Orchestrator feature.

Weve built on the open source foundations of KubeVirt, and delivered a simpler and more powerful experience for enterprises.

The result? Organizations that have committed to Kubernetes on their application modernization journey, and have already invested in Kubernetes skills and tools, will benefit from a single platform to manage both containers and VMs.

And thats not just as a temporary stepping stone for the applications that will be refactored, but also for hybrid deployments (applications that share VMs and containers) and for workloads that will always be hosted in VMs. Even after nearly 25 years of virtualization, VMs are certainly not dead yet.

To find out more about Palettes VMO feature, check out our website or our docs site. Wed love to get your feedback.

Originally posted here:
The Future of VMs on Kubernetes: Building on KubeVirt - The New Stack