Clusternet vs Karmada

Clusternet is a free, open-source add-on for managing Kubernetes clusters across public and private cloud, hybrid, on-premises, and edge environments. It lets operators manage member clusters from a parent cluster and access them as though they were local. It deploys Kubernetes resources, custom resource definitions, and Helm charts, with configuration tailored to individual clusters. Application scheduling can replicate workloads or distribute them by cluster weight or available capacity. Clusternet supports 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 VPC networks, at the edge, or behind a firewall. Dynamic RBAC rules control access to managed clusters, and Submariner integration can connect workloads across clusters. Installation options include Helm and manual setup. A kubectl plugin is available through Krew or as a binary. Linux builds are listed for several architectures. Clusternet is a CNCF Sandbox project.

Karmada manages cloud-native applications across multiple Kubernetes clusters and clouds without requiring changes to the applications. It supports public and private cloud, on-premises, edge, and self-built environments that meet Kubernetes specifications. Cluster connections can use Push mode through a Kubernetes API server or Pull mode through an in-cluster agent. Scheduling policies cover cluster affinity, taints and tolerations, topology spread, and replicated or divided placement. OverridePolicy allows per-cluster changes to images, arguments, commands, and plain-text configuration. Karmada can move replicas after a cluster failure, including migration that avoids service replicas dropping to zero. Through karmada-apiserver, teams can create, update, delete, and query resources across member clusters. Its components export Prometheus metrics; integrations described include Submariner networking and ErieCanal service governance. Installation options include CLI tools, Helm, an operator, binaries, or source. The CLI initialization requires escalated privileges to store shared configuration under /etc/karmada by default. Karmada is open source and free, with customer-managed control plane; it manages clusters but does not provision them.