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.