Unveiling vSphere with Tanzu: The Architecture That Powers Enterprise Kubernetes

For years, VMware vSphere has been the go-to solution for virtualization, helping businesses cut costs, boost resource efficiency, and simplify server management with features like HA, vMotion, and DRS.

However, as containers and Kubernetes reshape enterprise IT, organizations need to integrate modern cloud-native apps with their existing virtualized workloads. Enter vSphere with Tanzu, VMware’s solution for running VMs and Kubernetes side by side on a unified platform. In this first article of the series, I’ll break down the core architecture of vSphere with Tanzu and how it powers Kubernetes in the enterprise.

1. The Big Picture: What is vSphere with Tanzu?

vSphere with Tanzu is an extension of VMware vSphere, enabling native Kubernetes functionality on the hypervisor layer. Traditionally, vSphere has been a go-to solution for managing VMs, but with Tanzu, it now becomes a powerful platform for running containerized applications alongside VMs directly on ESXi or to deploy upstream Kubernetes clusters within dedicated resource pools. This means enterprises can modernize their applications without the need for separate infrastructures, leading to simplified operations and cost efficiency.

2. Key Components of vSphere with Tanzu

2.1 Supervisor Cluster

When vSphere clusters are enabled as Supervisors, a Kubernetes control plane is created within the hypervisor layer, enabling the execution of Kubernetes workloads within ESXi. The Supervisor architecture includes:

• SDDC layer: Consists of ESXi for compute, NSX/VDS for networking, and vSAN/shared storage for persistent volumes.
• vSphere Namespaces: These act as logical boundaries within a Supervisor Cluster for managing and organizing Kubernetes workloads and resources.
• High Availability: Can be deployed across three vSphere zones (cluster-level HA) or a single cluster (host-level HA).

Key Components:

• Supervisor control plane VMs: Three VMs are deployed across zones/hosts for load balancing and high availability.
• TKG and Cluster API: Manages provisioning and operation of Tanzu Kubernetes clusters.
• VM Service: Handles deployment of VMs, including those in TKG clusters.
• Spherelet: A kubelet native to ESXi, allowing ESXi hosts to join Kubernetes clusters.
• CRX (Container Runtime Executive): A paravirtualized Linux kernel allowing vSphere Pods to boot quickly, with strong VM-like isolation.

2.2 vSphere Pods

vSphere with Tanzu offers vSphere Pods. These are lightweight VMs that run one or more Linux containers, similar to Kubernetes pods. These pods are resource-efficient, with explicit allocations for CPU, memory, and storage, and are supported only in Supervisor Clusters using NSX-T Data Center for networking. Key features include:

• Strong isolation, with each pod having its own unique Linux kernel.
• Resource management via vSphere DRS for optimized placement.
• High performance, providing isolation similar to VMs while maintaining container agility.
• Diagnostics tools from vSphere are available for monitoring workloads.

It can run containers with any OS as vSphere Pods are Open Container Initiative (OCI) compatible.

2.3 Tanzu Kubernetes Grid (TKG)

A Tanzu Kubernetes Cluster is a full distribution of open-source Kubernetes, built and supported by VMware, designed to run natively on vSphere infrastructure through the Tanzu Kubernetes Grid Service (TKGS). It runs on a Supervisor Cluster, which is a vSphere cluster that is enabled with Tanzu to manage Kubernetes workloads directly.

Key Characteristics:

• Opinionated Kubernetes Installation: Streamlined and optimized installation of Kubernetes with well-defined defaults.
• vSphere Integration: Tanzu Kubernetes clusters are deeply integrated with the vSphere SDDC stack.
• Production-Ready: Production ready clusters with features like rolling upgrades, HA, and the ability to run different Kubernetes versions in separate clusters.
• Fully Supported by VMware: VMware provides end-to-end support with issue resolution.
• Kubernetes Management: Familiar Kubernetes tools (e.g., kubectl).

2.4 Comparison: vSphere Pods vs. Tanzu Kubernetes Clusters

vSphere Pods:

• VMware-specific lightweight VMs running containers.
• Provide strong resource isolation and fast deployment.
• Ideal for administrators or engineers who want containerized applications without managing full Kubernetes clusters.
• Best for simple, containerized workloads with minimal configuration.

Tanzu Kubernetes Clusters:

• Offer full control over Kubernetes clusters, including access to the control plane and worker nodes.
• Allow customization with Operators, custom resource definitions (CRDs), and helm charts.
• Provide flexibility for DevOps and developers who need:

o   CI/CD pipelines.

o   Cluster-level access control.

o   Consistent updates to Kubernetes versions.

o   Complex cluster and workload management.

 3. How vSphere with Tanzu Integrates VMs and Kubernetes

The ability of vSphere with Tanzu to natively integrate Kubernetes workloads into vSphere via the supervisors is one of its key advantages. This integration is facilitated by a combination of components such as the vSphere Distributed Switch, NSX-T for networking, and vSAN or traditional storage solutions. This architecture allows both VMs and containers to coexist and share the same resources, making the infrastructure more efficient and flexible. The admins can manage both traditional VM workloads and Kubernetes applications from a single interface using VMware vCenter.

4. The Benefits of vSphere with Tanzu for Enterprises

The key advantage of vSphere with Tanzu lies in its ability to bridge the gap between traditional and cloud-native applications. Here’s how it benefits enterprises:

• Unified Platform: One platform to manage both virtual machines and containers
• Scalability: Ability to scale Kubernetes workloads rapidly across multiple clusters.
• Security and Isolation: With vSphere Pods, containers get isolated at the VM level.
• Developer Agility: Developers get self-service access to Kubernetes environments.

 5. Conclusion

Tanzu combined with vSphere is a game-changer for businesses trying to update their IT infrastructure. Because of its architecture, businesses may use Kubernetes without giving up on their investments on the current infrastructure. Through Tanzu's unified platform for managing virtual machines and containers, vSphere boosts scalability, improves security, and streamlines operations.