Specs Target Container Portability
Application containers are getting more portable across different implementations thanks to a two-year effort to forge "vendor neutral" specifications released this week by an industry group.
The Open Container Initiative (OCI) unveiled version 1.0 specifications addressing a container runtime along with an image format. Together, the specs aim to "lay the foundation for container portability across different implementations to make it easier for customers to support portable container solutions," the group said on Wednesday (July 19).
Along with the container image format, the stable runtime spec defines the life cycle of ephemeral containers. These guidelines will be combined with an OCI certification program to be launched later in the year that would demonstrate conformance with the container specs.
"By creating these open, accessible specifications, along with early deployments, we are bringing the industry closer to portability and standardization," Chris Aniszczyk, OCI executive director, noted in a statement.
Backers of the container standardization effort emphasize a maturing ecosystem they assert will pave the way for broader commercial adoption. Several recent industry surveys have found steady growth in container deployments. The latest released this week projected 12 billion downloads of Docker container components over the next several years, a 100 percent increase.
The portability features would allow the runtime and image format to be used across Linux, Windows or mainframes as well as on-premise or across multiple clouds.
Members also stressed interoperability with emerging cloud-native application platforms. For example, the Cloud Foundry Foundation said it has already adopted OCI's runC as its primary container runtime library for Linux nodes and is folding the OCI image format spec into the Cloud Foundry platform.
OCI was formed in 2015 to forge open container standards ostensibly designed to avoid vendor lock-in. Among its more than 40 members are key container stakeholders CoreOS and Docker along with Kubernetes developer Google (NASDAQ: GOOGL). The group also includes cloud vendors such as IBM (NYSE: IBM) and Microsoft (NASDAQ: MSFT).
Container rivals CoreOS and Docker also weighed in on the release of the runtime and image format specs. "It has been our goal to provide low-level standards as building blocks for the community, customers and the broader industry," Patrick Chanezon, Docker's chief developer advocate, noted in a blog post.
The stable specs "will help ensure users can create container images, using any number of OCI conforming tools, and be assured they will run on any number of container orchestration environments that can execute OCI conforming images," added Brandon Philips, CTO at CoreOS and chair of OCI's technical oversight panel.
"This will ensure teams can choose the build and runtime tools that best meets their needs and with this 1.0 release users can be confident that any images and tooling built against this release will receive wide support well into the future," Philips added in a separate post.
As container technology enters production, the rivals compete head-on in the container orchestration market. San Francisco-based CoreOS is a key backer of the Kubernetes container orchestration platform that competes with Docker's Swarm tool.
Market watcher 451 Research recently noted that container management and orchestration remains a "mixed-use market," with Kubernetes leading the way but not yet a "de facto standard."
Observers note that each approach has its advantages and disadvantages. Both Kubernetes and Swarm are open source tools, but Swarm is tied to Docker while several vendors including CoreOS contribute to the Google-developed orchestrator.
Meanwhile, OCI members noted that work is underway on other technical specifications such as a common networking interface for containers. That work is proceeding in conjunction with the Cloud Native Computing Foundation.