Native Ambient Mesh Support with vCluster v0.25

Kubernetes multi-cluster architectures have become essential for organizations pursuing high availability, geographic distribution, and workload isolation. However, these deployments introduce complex challenges in service discovery, identity management, and resource optimization. While Istio's service mesh architecture comprehensively addresses these problems through its advanced traffic management, zero-trust security model, and observability capabilities, deploying Istio across multiple clusters presents its own set of operational complexities.

vCluster's recently introduced Istio integration in the v0.25 release represents a breakthrough solution that addresses longstanding challenges in multi-cluster service mesh deployments while leveraging the cost-effective benefits of ambient mode and virtual clusters. This post explores how organizations can significantly reduce costs and operational complexity through the strategic combination of multitenancy and ambient mode architecture.

Multi-Cluster Operational Complexity

Many teams gravitate toward multi-cluster architectures as their preferred approach to multitenancy, seeking to reduce complexity while enabling cluster sharing within teams and managing Custom Resource Definitions (CRDs) for different organizational units.

The apparent simplicity of creating clusters on demand often masks critical Day 2 operational challenges, including the escalating costs of multiple control planes, redundant platform layers, complex inter-cluster connectivity requirements, and ongoing maintenance overhead.

Istio: A powerful Service Mesh

Istio, a CNCF graduated project, serves as a robust networking layer that addresses many of the challenges associated with securing and managing inter-service communication in distributed systems. It provides a unified service identity, centralized observability, and global load balancing all critical capabilities for modern cloud-native environments.

While Istio addresses many challenges, its deployment in a multi-cluster environment introduces operational complexities, including ambiguous service discovery patterns, mismatched authentication trust boundaries, and network latency variability. These issues can complicate identity resolution and lead to inconsistent policy enforcement across clusters.

Finding a solution that combines the benefits of Istio with the maintenance of multi-cluster deployment throughout teams remains a critical challenge for DevOps teams worldwide.

Diving Deep into Platform Layer with vCluster

A smart approach to platform architecture involves centralizing key infrastructure components such as Istio and other tooling like Ingress Controllers into a single shared configuration and share them between isolated tenants. Instead of duplicating these services across environments, organizations can streamline operations and reduce maintenance overhead by leveraging a unified setup.

To create isolated environments, vCluster has positioned itself as a popular OSS solution.

vCluster provides isolated environments that behave like independent clusters while sharing underlying host cluster resources, offering significant cost savings and operational simplification.

This virtual Kubernetes model provides strong tenant isolation while enabling platform administrators to optimize cost efficiency by sharing the platform layer and centralizing governance. Additionally, it facilitates the enforcement of consistent operational and security standards across all your isolated environments i.e., virtual clusters, thereby reducing complexity and variability at scale.

vCluster v0.25 Release: Istio Integration

With the release of vCluster v0.25, we have introduced a streamlined integration with Istio’s Ambient Mesh that significantly simplifies these processes by syncing DestinationRules, Gateways, and VirtualServices with more coming in future releases.

This feature allows organizations to run multiple virtual clusters that share a single Istio installation on the host cluster using the leading Ambient Mesh. With the mesh, you streamline your infrastructure and don’t worry about:

1. Resource overhead: Traditional Istio deployments use a sidecar proxy for each pod, meaning a cluster with 1,000 pods would require 1,000 sidecars each consuming CPU and memory. This results in significant resource consumption and scalability challenges. Ambient mode introduces a split architecture that breaks the sidecar into two distinct components saving compute and memory both.

2. Operational Complexity: Managing and upgrading thousands of sidecars adds considerable deployment and maintenance overhead, as every application pod must be restarted to update the sidecar version. Ambient mode solves these.

The best part? To enable it, just modify your vcluster.yaml to add the enabled:true flag, and vCluster does all the heavy lifting.

integrations:
  istio:
    enabled: true

The Benefits

With the v0.25 release, setting up multi-tenant environments with a powerful service mesh networking is as easy as it gets. Here’s what you get:

Shared Istio infrastructure

vCluster enables multiple virtual clusters to share a single Istio control plane on the host cluster, eliminating redundant installations. For example, in the diagram below, you can see the Istio system has been configured and used by N virtual clusters:

Operational Simplification

With a centralized Istio configuration across all of your tenants, you provide your tenants the option to configure L7 loadbalancing whenever they want it. vCluster automatically handles label propagation (istio.io/dataplane-mode), and DNS resolution.

There’s no need for per-cluster CRD synchronization or Istio Configuration.

Gateway Access Wake

In this release, you’ll also find Gateway Access Wake, a cost-saving feature that works in tandem with vCluster Sleep Mode. When vCluster is asleep, incoming traffic routed to a Service in the vCluster is tracked as activity. This activity triggers the vCluster to wake up automatically, ensuring seamless access.

Additionally, vCluster continuously synchronizes Gateway and VirtualService resources to the host cluster whenever there is traffic, keeping the vCluster awake for as long as needed. Read more about this feature in the official docs.

Scalability Advantages

Each virtual cluster has a dedicated API server that isolates Custom Resource Definition (CRD) management and Role-Based Access Control (RBAC) requests from the host cluster. This setup prevents conflicts related to Istio CRDs.

The best part is that you can configure L7 capabilities on a per-virtual cluster basis, rather than being restricted by an all-or-nothing approach. This not only saves costs but also maintains strict isolation between teams and business units while allowing them to share critical platform services like Istio.

Final Thoughts

By combining the power of vCluster and Istio, organizations can unlock new levels of networking flexibility, security, and efficiency in their multi-tenant environments. With simplified setup, centralized management, and robust scalability, vCluster v0.25 is designed to help teams modernize their infrastructure while reducing costs and operational complexity and ensuring your platform can grow alongside their business needs.

We’re excited to see how you’ll leverage these new capabilities in your projects. Whether you’re just getting started or looking to optimize your existing setup, we’re here to support you every step of the way.

For more details and a walkthrough example, explore the official vCluster Istio documentation. Have questions or want to connect with peers? Join our Slack channel and become part of a growing community of innovators.