By Tim Clark
July 5, 2017
Over the years, one rap against container orchestration software Kubernetes has been that it didn’t handle certain functions—relational databases or persistent storage for example—as well as other options such open-source Mesos.
If that slander was ever true, the Kubernetes community is now addressing it. Version 1.7 was launched June 29. Kubernetes 1.7, termed a “milestone” release, in a blog post, hardens security, addresses stateful applications, and pursues extensibility—all aimed tightly at the most demanding enterprise environments, exactly where Mesos has made its mark.
If 1.7 is more enterprise-friendly, that’s not good news for everyone. A whole ecosystem has built up around containers to address shortcomings in Kubernetes and Docker by extending functionality. V1.7 and the general direction of Kubernetes (to add more enterprise appeal) threatens to undermine some ecosystem Docker companies. Think Robin Systems, which was built to run database software in a container infrastructure. Or Rancher Labs, which created a container infrastructure to manage storage and other elements.
“Database users want to use local storage,” said Dawn Chen, tech Lead for Kubernetes at Google and Kubernetes 1.7 release team lead. That feature is in alpha with the 1.7 release.
For scale-out databases on Kubernetes, this release adds automated updates to StatefulSets and enhances updates for DaemonSets. The Kubernetes team also announced alpha support for local storage and a burst mode for scaling StatefulSets faster.
Security enhancements in this release include encrypted secrets, network policy for pod-to-pod communication, node authorizer to limit kubelet access, and client/server TLS certificate rotation.
An API aggregation feature in 1.7 allows power users to add Kubernetes-style pre-built, third-party or user-created APIs. StatefulSet Updates is a new beta feature in 1.7, allowing automated updates of stateful applications such as Kafka, Zookeeper and etcd, using a range of update strategies including rolling updates. A new StorageOS Volume plugin provides highly-available cluster-wide persistent volumes from local or attached node storage.
Kubernetes 1.7 is available for download on GitHub. The Linux Foundation announced users of Kubernetes 1.7 including Box, GolfNow, Wink, Buffer, Ticketmaster, Ancestry.com, BlaBlaCar, Amadeus, eBay, BlackRock, Haufe-Lexware, and Huawei.