Containers and virtual machines are very similar, and they want to occupy the same space in the data center. Surely that means they must be on some sort of collision course, and things can only get messy as a result, right?
That would seem to be the natural conclusion when you consider how much overlap there is between container and virtualization technology and functionality. But of course things aren't quite that simple.
So perhaps it was not so strange to see the announcement in early March that VMware is now supporting CoreOS on both its vSphere 6.0 and 5.5 server virtualization platforms and its vCloud Air public cloud platform.
But it is surprising. That's because CoreOS is a lightweight Linux operating system with only the minimal functionality required for things like deploying applications inside software containers. VMware in other words has gone out of its way to make sure that containers can be accommodated nicely in its proprietary world of virtualization technology.
A Strategic Move That's Not Such a Surprise After All?
So just how surprising is it? It's worth remembering that VMware has been quite clear for some time that it doesn't regard containers as a threat to its virtualization technology business. Back in August of last year VMware vice president Kit Colbert has this to say:
"VMware sees tremendous value in containers. In fact, VMware has actually been a huge proponent of containers for many years now. You could even call us a pioneer of containers in the enterprise space, as we created a container system called Warden for CloudFoundry back in the fall of 2011.
"We did this exactly because we realized the need for simple application delivery into an isolated OS environment. Thus we're very excited to see Docker catalyzing the industry around containers, as they streamline application delivery and help to make customers even more successful.
"Second, we [VMware] see containers and virtual machines as technologies that function better together. …It's not just the basic runtime that containers enable, it's about providing mature, enterprise-proven infrastructure services to make customers successful running and operating containerized applications in production. By combining containers and virtual machines, customers can improve their ability to deliver applications without compromising their enterprise IT standards."
VMware and Containers Better Together than Apart
The key point here is the idea that VMware and containers are better together — and that comes from adding all the management capabilities that VMware offers to a fleet of Docker containers. And you only get that when CoreOS is fully supported, with full integration with VMware's management APIs.
What's happened now is now that CoreOS is available with open-vm-tools, the open source implementation of VMware Tools, and this enables management of CoreOS VMs running in all VMware environments, including the latest vSphere 6.0 and vCloud Air.
"By offering enterprises a common platform for running virtual machines and containers, developers gain agility and speed while offering IT teams the control they need," says Mark Lohmeyer, another VMware vice president. "Enterprises running containers within virtual machines can also benefit from high performance, security isolation, dynamic virtual networking, software-defined storage, and the extensive ecosystem of third-party solutions developed for virtual machines."
So what's really going on? Is this a case of VMware keeping its friends close, but its enemies closer? Possibly. After all, containers aren't going away, so by bringing them into the VMware fold it can keep container users as customers.
Or does VMware really believe the "better together" mantra? Other container management systems exist — like Google's Kubernetes — but none are as comprehensive as VMware's.
Maybe it's a case of both being true. As long as customers continue to use – and pay for – its infrastructure, VMware probably doesn't care what you do with it.
Paul Rubens is a technology journalist and contributor to ServerWatch, EnterpriseNetworkingPlanet and EnterpriseMobileToday. He has also covered technology for international newspapers and magazines including The Economist and The Financial Times since 1991.