What's new in Kubernetes 1.21?
An incredible number of 51 enhancements and 2 deprecations in the new release to address many enterprise issues
The Kubernetes community expressed pleasure when announcing the release of Kubernetes 1.21 on April 8, 2021. This release focuses on correcting a field of operational and security problems making the platform easier to manage and monitor.
These 51 enhancements are categorically into the stable, beta, and alpha stages
The stable stage has been enhanced with the addition of significant capabilities. One of these is the graduated schedule function, CronJobs.
The Graceful Node Shutdown capability and IPv4/Ipv6 dual-stack support grace the beta stage.
In terms of the Alpha stage’s major capabilities, there is the introduction of a Persistent Volume Health Monitor.
Kubernetes’ Technical Oversight Committee recently gave the green light to release a version 1.21 update that poaches service mesh welfare. Proceedings verify that there are several Application Programming Interfaces (APIs) that the committee has decided to, once again, throw under the bus. The PodSecurity Policy falls inside this list. It was previously available in the beta stage but has now been substituted for a currently unnamed system that limits privileges that will be easier to employ.
The Kubernetes 1.21 release team leader and VMware open source engineer Nabarun Palclaimed that these disapprovals are crucial for the Kubernetes platform, emphasizing the importance of awareness so teams can keep track of deprecation changes over time. Many organizations, of course, delegate these tasks to vendors who typically implement capabilities in tracking stable stage changes.
This release cycle generated major shifts in process ownerships around the release team. The company periodically communicated with the community to contribute in anticipation of the release. The results increased collaboration and teamwork across the community, birthing a project endowed with contemporary features in Kubernetes 1.21.
CronJobs, previously known as ScheduledJobs, has been around (in beta) since Kubernetes version 1.8. It has now been graduated to stable and was designed for regular scheduling such as report generation, backups, and more. These tasks should be wired based on preferences like daily intervals or weekly or monthly.
Immutable Secrets and ConfigMaps provide new options to those resource types rejecting changes to those objects if set. Changes consumption by pods will be enhanced by the default mutable nature of Secrets and ConfigMaps. Mutating Secrets and ConfigMaps are exposed to problems provided whenever there is a wrong configuration for relevant pods. Users can be sure of unchangeable application configuration by making Secrets and ConfigMaps immutable. Immutable resources enjoy scaling benefits, and this comes down to controllers not needed to poll the API server to monitor changes.
IP addresses signify consumable resources that cluster operators and administrators have to manage. With the abundance of IPv6 and scarcity of IPv4, the dual-stack support enables pods and services to be routed natively to IPv6 while still allowing cluster communication with the IPv4 when necessary. Dual-stack networking in Kubernetes 1.21 has graduated from alpha to beta.
This new release graduated the Graceful Node Shutdown from the alpha stage and is now available to more users. This feature prompts the Kubelet after a node shutdown, “gracefully shutting down” pods relevant to the node.
Persistent Volumes (PV) widely known for local, file-based repositories. They are very flexible and help users with application migration without the need for storage rewrite.
PodSecurityPolicy is being deprecated in Kubernetes 1.21, along with TopologyKeys.
Capabilities like EndPoint Slice and PodDisruptionBudgets also graduated to stable.