“Just because you can start using containers doesn’t mean that you should,” said the lone woman on the OpenStack panel of experts. She is Caroline McCrory, vice president of business development for Cloudsoft, a cloud orchestration platform maker.

But McCrory isn't alone. She's just one among a growing chorus of OpenStack professionals who have doubts about the pervasive influence of Docker, the containerization technology whose disruptive affect has already metamorphosed some of the world’s major data centers.

Abstraction on Top of Abstraction

Wednesday morning at a panel session at the OpenStack Summit in Vancouver, McCrory and five others spoke amid the scenic backdrop of an oceanic tanker whose shipping containers were ablaze and engulfed in smoke.

At issue for these panelists was whether OpenStack — whose original purpose was to manage virtual machines in hybrid clouds — is being aided or threatened by Docker, which virtualizes workloads in a completely different manner.

“You’ve got so many layers of abstraction built on layers of abstraction that actually tracking down and resolving issues becomes very, very difficult,” said Jesse Proudman, the founder and CTO of Blue Box, an OpenStack private cloud provider.

Proudman was explaining a situation his own organization faces every day, with respect to debugging failure events. Already with OpenStack, tracking down the source of failure is difficult.

Pairing the virtual machines (VMs) managed by OpenStack’s tools with the containers managed with tools like Kubernetes and Mesos for Docker ends up making life more complicated for Blue Box.

This doesn’t exactly jive with the picture of Docker as a system of “radical simplification,” as many folks have called it, including me. In the past, I’ve also used that same phrase to characterize virtualization.

But Wait A Minute

Aren’t they the same thing, you may ask? In the sense that operating a 747 and operating an RC plane are both “piloting,” yes. As far as accomplishing the same goal in the same way, not really.

Virtualization makes application workloads portable across servers, and now across clouds. But virtual machines (VMs) were the first vehicles for running those workloads portably. They build environments around applications that make them “believe” they’re in an operating system at the lowest levels of the processor, when they’re really floating along the higher layers of the virtualization plane.

Vendors led by VMware built an industry around managing complex ecosystems around VMs, and making physical resources available to virtual systems. OpenStack blew the top off of vSphere’s best-laid plans, using a concept first tested at NASA to make virtual systems use huge pools of resources without all the complex mapping.

The Shoe Changes Feet

So should the old VMware generation of data center architecture make way for the new generation of OpenStack? At one point, even OpenStack’s co-creators at Rackspace concluded that the two architectures should co-exist, while OpenStack gets a chance to evolve.

But that was April 2014. Just since then, Docker has evolved from a curiosity into a top-of-mind topic in IT, kicking OpenStack into the seat held last year by vSphere: the older technology that either has to get with the program or face obsolescence.

Now, OpenStack’s proponents find themselves uttering generally the same arguments that vSphere’s proponents used last year: Since old applications won’t go away any time soon, architectures designed for virtualizing old applications must keep their seats at the table.

McCrory’s comment about whether one should use containers just because one can, contributed to her broader point on this topic: Not only are there use cases for which containers are best-suited, there are others for which Docker and other container technologies have yet to prove themselves.

“I personally am seeing a lot of people wanting to use containers as if they would just replace their VMs,” she said, “and get away from VMware licensing ... There are applications that have specific behaviors that you cannot just throw into a container. It will be awhile before containers are mature enough to deal with some of those workloads.”

Boris Renski, co-founder and chief marketing officer of OpenStack distributor Mirantis, added:

In reality, there is an element of truth that there are a number of use cases where containers are better than VMs, and there’s also a lot of truth around the fact that OpenStack has historically been very VM-centric. A lot of architectural decisions in OpenStack have been made around solving the problem of how to manage your VM. So there is an element of threat, which I think is good for everybody to go ahead and openly discuss."

Renski took credit for the idea for the panel: “Are Containers a Threat to OpenStack?” He told one questioner that he’s a marketing guy, and any headline with “containers” and “OpenStack” in the headline should attract attention. (I should try that sometime.)

But Renski’s words were especially prophetic in the light of history, which takes place these days in ever-shorter intervals. In September 2012 for the Mirantis corporate blog, Renski penned an article declaring the OpenStack Foundation’s acceptance of VMware as a member a “mistake.”

In that article, the CMO said he feared OpenStack had allowed itself to be “subdued” by VMware, whose only interests in his belief were to keep OpenStack at bay while it continues to push vSphere as an “end-to-end solution.”

Orchestrating the Endgame

Since then, VMware has contributed not only support and expertise but actual code toward one of OpenStack’s two leading Platform-as-a-Service (PaaS) platforms, Cloud Foundry — a VMware creation that was later stewarded by VMware spin-off company Pivotal. Cloud Foundry is arguably one of the jewels in the OpenStack crown.

“There has been a lot of hype around Docker, and its value primarily as a packager,” said Mirantis’ Renski at Wednesday’s panel. “But the long-term view, I think, on containers is that... its key value is in container orchestration. This is where everybody’s going now. Container orchestration is really nothing more than Platform-as-a-Service.”

Panelists went on to discuss whether Docker may be evolving into a PaaS that could, in future years (or months), threaten OpenStack’s position as a platform for supporting Cloud Foundry and Red Hat’s OpenShift PaaS. This while Red Hat lines up its OpenStack portfolio, including OpenShift, in an effort to consolidate OpenStack’s position as an “end-to-end solution.”

“The question shouldn’t be, ‘Are containers a threat to OpenStack?’” said Blue Box’s Proudman. “It should be, ‘Are containers creating a new type of PaaS?’”

It’s always intriguing to watch corporations, over the course of history, swap the roles they play with one another — the villain with the victim, the conqueror versus the challenger, the innovator against the manufacturer. But it’s even more fascinating, with respect to information technology, to watch it all happen in time lapse.

Creative Commons Creative Commons Attribution 2.0 Generic License Title image by Rakesh Rocky.