Clusternet

Clusternet is a free, open-source add-on for managing Kubernetes clusters across public and private clouds, hybrid environments, on-premises systems, and edge locations. Operators manage member clusters from a parent cluster and can access them as though they were local. Clusternet deploys Kubernetes resources, custom resource definitions, and Helm charts, including OCI-based charts, with configuration for individual clusters. Scheduling can replicate applications, distribute them by cluster weight, or allocate them according to cluster capacity. The project lists support for clusters from AWS, Google Cloud, Tencent Cloud, and Alibaba Cloud, along with on-premises systems, k3s and edge clusters. It can discover and register clusters created by Cluster API, and configure network tunnels for clusters in VPCs, at the edge, or behind firewalls. Dynamic RBAC rules govern access to managed clusters. Integrations include Submariner for connecting workloads across clusters and private Helm chart registries. Installation guides cover Helm, manual setup, and k3s. A kubectl plugin is available through Krew or as a downloadable binary.

Clusternet provides centralized management and several deployment strategies for Kubernetes environments spanning different locations. Check the version compatibility guidance and setup notes when planning a deployment.

Clusternet suits teams that need to manage and deploy applications across multiple Kubernetes clusters. It is aimed at operators working across cloud, on-premises, hybrid, and edge environments.

Overview

Clusternet is an open-source add-on for centrally managing Kubernetes clusters across cloud, on-premises, hybrid, and edge environments. It is best suited to teams already running Kubernetes that need to coordinate applications across multiple clusters. Its appeal is a capable multi-cluster control point with no software charge; its fit depends on release compatibility and a team prepared to manage the installation.

Key features

Operators manage member clusters from a parent cluster and can access them as though they were local. That gives teams a central way to work across a distributed fleet, while keeping day-to-day use tied to Kubernetes operations and the parent-cluster model.

Clusternet deploys Kubernetes resources, CRDs, and Helm charts, including charts from OCI registries, with configuration tailored to each cluster. It can also discover and register clusters created through Cluster API. This suits teams that need repeatable application delivery across a fleet without treating every cluster as identical.

Scheduling supports replication, static distribution by cluster weight, and dynamic distribution by cluster capacity. The range gives operators control over whether applications should be copied broadly, placed according to set weights, or distributed in response to capacity.

For connectivity, Clusternet can configure network tunnels for clusters in VPCs, at the edge, or behind firewalls, and documents integration with Submariner for securely connecting workloads between member clusters. Access is governed through dynamic RBAC rules. Where child-cluster security is a concern, administrators can disable the AppPusher feature gate on an agent.

The project provides a kubectl plugin installable through Krew or as a binary, plus a client-go wrapper for integrations. Helm and manual installation paths are documented, including guidance for k3s. The quick-start notes that kind environments with several clusters and many pods can run into inotify limits, which may prevent pods from starting; teams using that setup should account for the host resource constraint.

Pricing

Clusternet (open source): free. The project is open source, with no paid plans or usage limits stated. The control plane is customer-managed, so teams take responsibility for operating it. This makes Clusternet a strong fit when software cost and control matter more than a hosted management service.

There are no paid tiers with different feature sets or seat quotas. The practical trade-off is that teams need to plan their own deployment and support: help is available through the project mailing list, CNCF Slack, Google Group, or a GitHub issue.

Platforms

Clusternet supports Linux builds for amd64, arm64, ppc64le, s390x, 386, and arm, and is offered as an API-based, self-hosted tool. It targets public and private cloud, hybrid, on-premises, and edge environments. The project says it manages Kubernetes versions above v1.17.x and documents compatibility by Clusternet release. Versions below v0.13.0 have no guaranteed support for Kubernetes versions above v1.24.0, so teams should check the release-specific guidance before upgrading or deploying.

Who it's for

Clusternet fits Kubernetes platform teams responsible for several clusters across providers or locations, especially when they want centralized access, cluster-aware application delivery, and control over where workloads are placed. Its customer-managed model and installation paths also suit organizations that prefer to run their own management plane.

It is a weaker fit for teams seeking a managed service or a tool that removes the need for Kubernetes operational expertise. Teams with older Clusternet releases should also treat Kubernetes compatibility as a deployment constraint, not an afterthought.

Pros and cons

• Pros: Central management across cloud, on-premises, and edge clusters gives operators one parent-cluster access model for a varied fleet.
• Pros: Replication and weight- or capacity-based scheduling let teams choose how applications are distributed.
• Pros: Open-source pricing has no stated usage caps, and the project supports common Kubernetes resources, CRDs, Helm charts, and OCI charts.
• Cons: Customer-managed control plane and documented Helm or manual setup put deployment and operations on the adopting team.
• Cons: Compatibility varies by release; older versions do not guarantee support for Kubernetes above v1.24.0.
• Cons: Busy, multi-cluster kind setups may hit inotify limits and fail to start pods.

Alternatives

For teams focused on provisioning Kubernetes clusters through provider components, Cluster API is also free and open source, though infrastructure and provider costs depend on the selected providers.

Kubermatic Kubernetes Platform offers an open-source Community Edition and a consumption-based Enterprise Edition, making it an option for teams comparing community software with an enterprise offering.

openCenter has a free Community plan for builders and proofs of concept, with self-support.

Portainer offers a free Business Edition tier for up to three nodes with full features and no time limit; teams within that cap may prefer its stated node limit and feature access.

vCluster Platform has a free tier with unlimited virtual clusters up to 64 CPUs or 32 GPUs and a maximum of one HA vCluster, which may suit teams looking for virtual-cluster capacity within those limits.

Kamaji is a free Apache 2.0 open-source option.

Karmada is another free, open-source Kubernetes management system.

kOps is a free option for Linux, macOS, and Windows.

Browse Kubernetes Management Platforms for more options.

Verdict

Choose Clusternet if your team already operates Kubernetes and needs a free, self-managed way to coordinate access, deployments, and scheduling across a geographically or technologically varied cluster fleet. Its deployment breadth and flexible placement strategies make it compelling for platform teams. Look elsewhere if you need a managed control plane or want to avoid release-by-release compatibility checks and setup ownership.