Spec Spat: Red Hat Warns of Container ‘Fragmentation’
With parts of the emerging application container infrastructure moving ahead on separate tracks, a key player is reiterating its support for a set of open standards for packaging, orchestration and distribution of application containers.
The goal of the container open standards push, Red Hat said in a blog post, is avoiding fragmentation, which the company called a "community killer."
The blog post on Wednesday (May 6) was prompted in part by an announcement earlier in the week that Red Hat would contribute to a container distribution standard called Application Container Spec, or appc. The spec is being pushed by CoreOS, which also announced this week at a company event that it has implemented the spec in a container runtime called rkt.
Along with Red Hat, Google, Twitter and VMware also endorsed appc.
Red Hat moved after the announcement to qualify its support for appc: "As it is today, appc only covers a very small part of what needs to be sorted out for a container-based, application-centric model," it stressed.
The open source vendor noted that it "engages in many upstream communities" working on Linux container technologies, and would "actively contribute" to the CoreOS-backed spec. "However," Red Hat added, "this engagement should not imply full support, or that we consider appc or rkt ready for enterprise IT, or that the specification will ever be considered 'enterprise-ready'."
In an attempt to avoid the fragmentation of container technology, Red Hat reiterated its support for Docker as a standard container format. The company added that its "involvement [in the appc spec] does not diminish our existing commitment to container standards, nor does it imply that our involvement in other community projects mean that we are embracing or supporting them in our products."
At issue are differing visions of how the application container infrastructure should evolve. While Red Hat and many others are backing the Docker format, upstart CoreOS is actively promoting a container alternative called Rocket it claims is closer to the original vision of a simple, compatible container environment for Linux platforms.
The Linux OS vendor's announcement earlier this week that Google was backing appc created ripples across the container community. CoreOS said the backing includes integration of rkt as a configurable container runtime in Kubernetes clusters.
One thing CoreOS and Red Hat agree on is that the Kubernetes framework ought to be the standard for orchestration of multi-container applications. Google released Kubernetes to the open source community in July 2014.
Red Hat, which claims to be the second largest contributor to Kubernetes after Google, said the framework can "provide a consistent orchestration standard across many different environments, from on-premise to public clouds, while at the same time be able to optimize for each of these environments."
Given the thus far slow adoption of Docker containers in production environments, Red Hat also stressed that these attributes made Kubernetes "a good choice for enterprise IT looking to combine modernizing legacy with the push for innovation in a consistent manner."
While CoreOS insists that Docker should be viewed as a "platform" rather than simply a container technology, Red Hat countered that upstarts like CoreOS risk fragmenting the emerging container ecosystem. Hence, it stressed that the "core tenets of container infrastructure are the primitives for creating, distributing, running and managing containers, and we work towards avoiding fragmentation at this level."