Kubernetes 1.21 deprecates Pod Security and adds dual networking, cronjobs and more

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The latest release unloads pod security, adds dual IPv4/IPv6 networking, among other things.

The Kubernetes Release Team has given the green light to version 1.21 of the open-source container orchestration system. This new version marks the first Kubernetes release of 2021. The version offers many different enhancements.

The Release Team announced the new version in a blog post on April 8. “This release consists of 51 enhancements, they said. The team said that 13 enhancements are graduating to stable, 16 enhancements are moving to beta, 20 enhancements are entering alpha. The team also deprecated 2 features.

“This release cycle, we saw a major shift in ownership of processes around the release team. We moved from a synchronous mode of communication, where we periodically asked the community for inputs, to a mode where the community opts-in to contribute features and/or blogs to the release. These changes have resulted in an increase in collaboration and teamwork across the community.”

Here are the key changes

One of the more important enhancements is CronJobs, which has now graduated to a stable feature. CronJobs enables the scheduling of regular actions such as backups and generation of reports, typically once a day or week. Users can select a point in time within that interval when the job should start.

Another major change is that the Team have deprecated PodSecurityPolicy . This will no doubt dismay many Kubernetes users, since this feature is useful for restricting the scope of what deployments can do, such as limiting execution to a list of users, or access to resources like the network or volumes.

However, PodSecurityPolicy will continue to be available for several more releases. This is in line with the deprecation process. The final removal is going to be with Kubernetes 1.25.

Graceful Node shutdown also graduated to beta with this release (and will now be available to a much larger group of users)! The Team explains that this is a beneficial feature that allows the kubelet to be aware of node shutdown. It then gracefully terminates pods assigned to that node.