A year or so ago a schism surfaced in the container ecosystem as CoreOS, once one of the most important Docker ecosystem players, announced is own container standard. At the time, CoreOS's CEO Alex Polvi talked to the tensions within the ecosystem as the eponymously named commercial Docker entity tried to build a viable business and hence acted in ways which he suggested were not in the best interests of the broader community.
For this stated reason, CoreOS launched appc, an alternative container standard that was, in essence, in direct competition with Docker's own approach. In response, Solomon Hykes, Docker's founder and CTO, came out with a somewhat aggressive criticism of CoreOS' motivation for the move.
The split was seen as the first signs of tension within the broader Docker ecosystem and many suggested it was the first of many to come as the Docker commercial entity strives to find a way to justify its massive valuation.
At Dockercon yesterday, that schism was seen to have been repaired as Polvi and Hykes shook hands on stage and announced the launch of the Open Container Foundation. Hykes introduced a project aimed at producing a universal runtime for containers, enabling their creation to be accessible through a common language. The standard, entitled runC, includes, according to Hykes, "...basically all the code we ever wrote to manage OS containers, separated into a small, lightweight tool … It’s basically everything you need to run containers on a low-level system, and nothing else." runC is intended to make the code used by containers to access system services accessible to outside communication.
runC has some big contributors - Intel, IBM, Qualcomm, Microsoft and ARM are all involved. Docker has already contributed runC to the Linux Foundation, marking what many suggest is a resolution to the container specification war. And in defining the default, it's fair to say that Docker won this battle.
That's not to say that CoreOS lost. runC is, after all, a free and open standard that anyone can utilize. In its desire to build a more open base-standard for containers, CoreOS did some good work on behalf of the initiative with this. Polvi was positive about the move, writing in a blog post that:
Our experience developing App Container will play a critical role as we begin collaboration on the OCP specification. We anticipate that much of App Container will be directly integrated into the OCP specification, with tweaks being made to provide greater compatibility with the existing Docker ecosystem. The end goal is to converge on a single unified specification of a standard container format, and the success of OCP will mean the major goals of App Container are satisfied.
In terms of how the mechanics will play out, Polvi explained that the transition from appc to OCP will be smooth. CoreOS plans on being an important implementation of OCP. Beyond the technical details, this is a milestone occurrence for the young Docker initiative. That the two companies, Docker and CoreOS, could resolve their differences is an extremely positive sign that Docker is gaining a maturity beyond its age. It's also a breath of fresh air for those who were worried about concerning cracks in the broader Docker world.
