Tanzu Kubernetes Releases and Custom Node Images

This topic outlines how Tanzu Kubernetes Grid uses Tanzu Kubernetes releases (TKrs) and VM images to deploy clusters that run nodes with specific Kubernetes versions and operating systems.

Tanzu Kubernetes Releases

To support running diverse applications efficiently and reliably, you can customize Tanzu Kubernetes Grid (TKG) clusters to run its worker nodes and other VMs on different Kubernetes versions, operating systems, and operating system (OS) versions. For supported Kubernetes versions, VMware publishes Tanzu Kubernetes releases (TKrs), which associate a specific patch version of Kubernetes with compatible versions of a base OS plus compatible versions of additional components required by cluster nodes.

Each TKr contains everything that a specific patch version of Kubernetes needs to run on various VM types on various cloud infrastructures, and the management cluster uses a TKr to create a workload cluster that runs the desired Kubernetes and OS version.

How TKrs are published, how TKG uses them, and which Kubernetes versions they support depend on the management cluster deployment option:

• TKG with Supervisor:

  • TKr format and location: OVA templates in Tanzu content library
    • Update list of available TKrs with kubectl get tanzukubernetesreleases
    • See Using Content Libraries
  • How TKrs work, in vSphere with Tanzu Installation and Configuration:
    • Conceptual overview: About Tanzu Kubernetes release Distributions
    • Practical how-to: Topics under Creating and Managing Content Libraries for Tanzu Kubernetes releases
  • Supported Kubernetes versions:
    • See Compatibility for VMware Tanzu Kubernetes releases in VMware Tanzu Kubernetes releases Release Notes

• TKG with standalone management cluster:

  • TKr format and location: Machine images in library on IaaS
    • Defined by BoM files installed with Tanzu CLI to local ~/.config/tanzu/tkr/bom directory
    • Update list of available TKrs with tanzu kubernetes-release get
  • How TKrs work, in Tanzu Kubernetes Grid v2.1 Documentation:
    • Conceptual overview: Tanzu Kubernetes Releases
    • Practical how-to: Multiple Kubernetes Versions
  • Supported Kubernetes versions:
    • See TKG with standalone management cluster: Supported Kubernetes Versions in Tanzu Kubernetes Grid v2.1 in VMware Tanzu Kubernetes Grid 2.1 Release Notes

Custom Node Images (Standalone Management Cluster)

For TKG with a standalone management cluster, TKrs distributed by VMware support a selection of OSes by default, as listed in the Target Operating Systems table below.

You can also create clusters based on additional OSes listed as Custom image in the table. To do this, you run Kubernetes Image Builder and create a custom TKr as described in Build Machine Images.

Target Operating Systems (Standalone Management Cluster)

The following table shows the operating systems for cluster nodes that Tanzu Kubernetes releases support:

	vSphere	AWS	Azure
Distributed with TKG	Ubuntu 20.04 Photon OS 3	Ubuntu 20.04 Amazon Linux 2	Ubuntu 20.04 Ubuntu 18.04
Custom Image (see Build Machine Images)	Ubuntu 20.04 Ubuntu 18.04 RHEL 8 Photon OS 3	Ubuntu 20.04 Ubuntu 18.04 Amazon Linux 2	Ubuntu 20.04 Ubuntu 18.04