Cluster coordinator Kubernetes claims crisp care clip

Kubernetes, the popular open-source software for managing containerized applications, is scheduled for a feature infusion on Thursday, in accordance with its bump to version 1.8.

Backed by the likes of Google, IBM, Microsoft, Oracle, and Red Hat, Kubernetes provides more than half of the Fortune 100 companies with a way to create a coherent code development and deployment scheme that spans on-premises and hybrid cloud systems.

"The Kubernetes project has become incredibly popular as a target platform for containerizing workloads," said Caleb Miles, technical program manager at CoreOS, and Kubernetes 1.8 features 2nd release lead, in a phone interview with The Register.

Kubernetes 1.8 is the project's third release this year and focuses more on embellishing existing features than introducing new ones.

Jaice Singer DuMars, Kubernetes ambassador for Microsoft, DevOps servant leader, and Kubernetes 1.8 release team lead, said the Kubernetes team has been trying to focus on stability for even-numbered releases.

"We're not patching huge holes in functionality or missing pieces in Kubernetes core," he said. "It's about how do we broaden and harden these Kubernetes primitives."

Access controls

As described in a draft blog post by Aparna Sinha – group product manager for Kubernetes at Google – and Ihor Dvoretskyi – developer advocate for the Cloud Native Computing Foundation – the code's security capabilities have been improved with role-based access controls and a new privilege escalation restriction capability, both now designated as stable features. There's also kubelet client certificate rotation, to fetch new certs for those about to expire, and expanded network policy options.

The update also attempts to bring more simplicity to the software, because users appreciate such niceties. According to Sinha and Dvoretskyi, "This release expands the capabilities of kubeadm, which is both a user-facing tool to manage clusters and a building block for higher-level provisioning systems."

There's now an upgrade command for Kubeadm, and the ability to self-host the cluster control plane is available as an alpha preview.

Attention has also been paid to stability improvements. "Cluster autoscaler has improved performance and provides more usable error output to help understand scalability," said Sinha and Dvoretskyi.

"Users now have more control over storage: with features like the ability to set requests and limits on ephemeral storage, the ability to specify mount options, more metrics, and improvements to Flex driver deployments."

What's more, Kubernetes CronJobs, which allow tasks to be run periodically, have made it to beta status, and Spark has been validated to run on Kubernetes.

The update also brings the deprecation of a beta feature called Third Party Resource in favor of Custom Resource Definitions, the newly blessed mechanism for extending the Kubernetes API.

Despite the supposed focus on enhancement over new features, several new capabilities have been added in alpha status. These include:

• A means of prioritizing pods in a cluster
• A way to prevent pods from scheduling to a node
• A method for creating volume snapshots
• Support for IPVS mode in Kube-proxy

Kubernetes has been successful for a number of reasons. Beyond the proven utility of the software, Google's success in avoiding the perception that this is a partisan technology, broad industry desire for a way around AWS lockin, and a well-run community – the project's vitality can be attributed to a focus on both development and management.

DuMars explained that there's a lot of work happening around the management of the project.

"You're really seeing an emerging concern for the long-term arc of Kubernetes," said DuMars. "For me personally as a director, I want to know that the project is solid and sustainable."

The project's sustainability is also a concern among enterprises adopting the technology, because there's a large operational cost for strategic commitments.

"Kubernetes is not a flash in the pan," said DuMars. "We're seeing the establishment of a new technical standard that will lift and elevate the community." ®