Intel’s Clear Containers project adds support for Docker Swarm and Kubernetes


Intel Corp.’s Clear Containers software, which is a part of its larger Clear Linux project, has just received a major update that adds compatibility with the Docker Swarm and Kubernetes orchestration tools.

Intel’s Clear Containers bears the hallmarks of virtualization giant VMware Inc.’s approach to containers, which asserts they work best in production alongside a hardened hypervisor that enforces data isolation in hardware. Containers aren’t able to do this, but they can be launched and deployed much faster than hypervisors, and they also provide greater flexibility due to their portability across machines, shared repositories and maintenance.

Version 2.1.1 of Clear Containers, introduced Monday, represents Intel’s effort to enjoy the best of both worlds. In a 2015 blog post introducing the software, Intel engineer Arjan van de Ven said the aim was to “build a container system where one can use the isolation of virtual-machine technology along with the deployment benefits of containers.”

Clear Containers uses the KVM hypervisor, but tweaks from Intel that include leveraging system and a few kernel-level memory-organization tricks mean that memory consumption is minimized while performance is maximized. The software is compatible with the Open Container Initiative too, which means it can integrated with Docker 1.12 via the OCI’s runtime method.

Besides adding support for Docker Swarm and Kubernetes, Clear Containers 2.1.1 offers improvements including enhanced host-guest communication, support for Docker exec and Docker run, additional workload isolation with namespaces, and support for Kubernetes pod semantics, which means its now possible to start Clear Containers with the Container Runtime Interface.

Intel still has lots of work to do, however. As Intel’s Linux kernel developer Damien Lespiau points out on GitHub, installing Clear Containers on Red Hat Enterprise Linux still demands 71 individual commands, something the company will be looking to reduce in future updates.

Image: Krunja Photography /