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FAQ

The FAQ is updated periodically and designed to answer the questions our users most frequently ask about K3s.

Is K3s a suitable replacement for Kubernetes?​

K3s is a CNCF-certified Kubernetes distribution, and can do everything required of a standard Kubernetes cluster. It is just a more lightweight version. See the main docs page for more details.

How can I use my own Ingress instead of Traefik?​

Simply start K3s server with --disable=traefik and deploy your ingress.

Does K3s support Windows?​

At this time K3s does not natively support Windows, however we are open to the idea in the future.

What exactly are Servers and Agents?​

For a breakdown on the components that make up a server and agent, see the Architecture page.

How can I build from source?​

Please reference the K3s BUILDING.md with instructions.

Where are the K3s logs?​

The location of K3s logs will vary depending on how you run K3s and the node's OS.

  • When run from the command line, logs are sent to stdout and stderr.
  • When running under openrc, logs will be created at /var/log/k3s.log.
  • When running under Systemd, logs will be sent to Journald and can be viewed using journalctl -u k3s.
  • Pod logs can be found at /var/log/pods.
  • Containerd logs can be found at /var/lib/rancher/k3s/agent/containerd/containerd.log.

You can generate more detailed logs by using the --debug flag when starting K3s (or debug: true in the configuration file).

Kubernetes uses a logging framework known as klog, which uses a single logging configuration for all components within a process. Since K3s runs all Kubernetes components within a single process, it is not possible to configure different log levels or destinations for individual Kubernetes components. Use of the -v=<level> or --vmodule=<module>=<level> component args will likely not have the desired effect.

See Additional Logging Sources for even more log options.

Can I run K3s in Docker?​

Yes, there are multiple ways to run K3s in Docker. See Advanced Options for more details.

What is the difference between K3s Server and Agent Tokens?​

For more information on managing K3s join tokens, see the k3s token command documentation.

How compatible are different versions of K3s?​

In general, the Kubernetes version skew policy applies.

In short, servers can be newer than agents, but agents cannot be newer than servers.

I'm having an issue, where can I get help?​

If you are having an issue with deploying K3s, you should:

  1. Check the Known Issues page.

  2. Check that you have resolved any Additional OS Preparation. Run k3s check-config and ensure that it passes.

  3. Search the K3s Issues and Discussions for one that matches your problem.

  1. Join the Rancher Slack K3s channel to get help.

  2. Submit a New Issue on the K3s Github describing your setup and the issue you are experiencing.