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Lightweight Kubernetes. Easy to install, half the memory, all in a binary of less than 100 MB.

Great for:

  • Edge
  • IoT
  • CI
  • Development
  • ARM
  • Embedding K8s
  • Situations where a PhD in K8s clusterology is infeasible

What is K3s?

K3s is a fully compliant Kubernetes distribution with the following enhancements:

  • Packaged as a single binary.
  • Lightweight storage backend based on sqlite3 as the default storage mechanism. etcd3, MySQL, Postgres are also available.
  • Wrapped in simple launcher that handles a lot of the complexity of TLS and options.
  • Secure by default with reasonable defaults for lightweight environments.
  • Simple but powerful "batteries-included" features have been added, such as:
    • local storage provider
    • service load balancer
    • Helm controller
    • Traefik ingress controller.
  • Operation of all Kubernetes control plane components is encapsulated in a single binary and process. This allows K3s to automate and manage complex cluster operations like distributing certificates.
  • External dependencies have been minimized (just a modern kernel and cgroup mounts needed). K3s packages the required dependencies, including:
    • containerd
    • Flannel (CNI)
    • CoreDNS
    • Traefik (Ingress)
    • Klipper-lb (Service LB)
    • Embedded network policy controller
    • Embedded local-path-provisioner
    • Host utilities (iptables, socat, etc)

What's with the name?

We wanted an installation of Kubernetes that was half the size in terms of memory footprint. Kubernetes is a 10-letter word stylized as K8s. So something half as big as Kubernetes would be a 5-letter word stylized as K3s. There is no long form of K3s and no official pronunciation.