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 also still 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: a local storage provider, a service load balancer, a Helm controller, and the 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 required dependencies, including:
  • containerd
  • Flannel
  • CoreDNS
  • CNI
  • Host utilities (iptables, socat, etc)
  • Ingress controller (traefik)
  • Embedded service loadbalancer
  • Embedded network policy controller

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.