🚀 (said 'ketchup')
k3sup is a light-weight utility to get from zero to KUBECONFIG with k3s on any local or remote VM. All you need is
ssh access and the
k3sup binary to get
kubectl access immediately.
The tool is written in Go and is cross-compiled for Linux, Windows, MacOS and even on Raspberry Pi.
How do you say it? Ketchup, as in tomato.
What's this for?
This tool uses
ssh to install
k3s to a remote Linux host. You can also use it to join existing Linux hosts into a k3s cluster as
k3s is installed using the utility script from Rancher, along with a flag for your host's public IP so that TLS works properly. The
kubeconfig file on the server is then fetched and updated so that you can connect from your laptop using
You may wonder why a tool like this needs to exist when you can do this sort of thing with bash.
k3sup was developed to automate what can be a very manual and confusing process for many developers, who are already short on time. Once you've provisioned a VM with your favourite tooling,
k3sup means you are only 60 seconds away from running
kubectl get pods on your own computer. If you are a local computer, you can bypass SSH with
k3sup install --local
- Bootstrap Kubernetes with k3s onto any VM with
k3sup install- either manually, during CI or through
- Get from zero to
k3son Raspberry Pi (RPi), VMs, AWS EC2, Packet bare-metal, DigitalOcean, Civo, Scaleway, and others
- Build a HA, multi-master (server) cluster
- Fetch the KUBECONFIG from an existing
- Join nodes into an existing
k3sup is distributed as a static Go binary. You can use the installer on MacOS and Linux, or visit the Releases page to download the executable for Windows.
curl -sLS https://get.k3sup.dev | sh sudo install k3sup /usr/local/bin/ k3sup --help
k3sup is made available free-of-charge, but you can support its ongoing development through GitHub Sponsors
A note for Windows users
Windows users can use
k3sup install and
k3sup join with a normal "Windows command prompt".
In the demo I install Kubernetes (
k3s) onto two separate machines and get my
kubeconfig downloaded to my laptop each time in around one minute.
- Ubuntu 18.04 VM created on DigitalOcean with ssh key copied automatically
- Raspberry Pi 4 with my ssh key copied over via
Watch the demo:
Who is the author?
If you've benefitted from his open source projects or blog posts in some way, then and join dozens of other developers today by buying an Insiders Subscription
- Buy an Insiders Subscription via GitHub today
k3sup tool is a client application which you can run on your own computer. It uses SSH to connect to remote servers and creates a local KUBECONFIG file on your disk. Binaries are provided for MacOS, Windows, and Linux (including ARM).
👑 Setup a Kubernetes server with
You can setup a server and stop here, or go on to use the
join command to add some "agents" aka
workers into the cluster to expand its compute capacity.
Provision a new VM running a compatible operating system such as Ubuntu, Debian, Raspbian, or something else. Make sure that you opt-in to copy your registered SSH keys over to the new VM or host automatically.
Note: You can copy ssh keys to a remote VM with
Imagine the IP was
192.168.0.1 and the username was
ubuntu, then you would run this:
export IP=192.168.0.1 k3sup install --ip $IP --user ubuntu
Other options for
--cluster- start this server in clustering mode, for use with dqlite (embedded HA)
--skip-install- if you already have k3s installed, you can just run this command to get the
--ssh-key- specify a specific path for the SSH key for remote login
--local-path- default is
./kubeconfig- set the file where you want to save your cluster's
kubeconfig. By default this file will be overwritten.
--merge- Merge config into existing file instead of overwriting (e.g. to add config to the default kubectl config, use
--local-path ~/.kube/config --merge).
--context- default is
default- set the name of the kubeconfig context.
--ssh-port- default is
22, but you can specify an alternative port i.e.
--k3s-extra-args- Optional extra arguments to pass to k3s installer, wrapped in quotes, i.e.
--k3s-extra-args '--no-deploy traefik'or
--k3s-extra-args '--docker'. For multiple args combine then within single quotes
--k3s-extra-args '--no-deploy traefik --docker'.
--k3s-version- set the specific version of k3s, i.e.
--ipsec- Enforces the optional extra argument for k3s:
See even more install options by running
k3sup install --help.
Now try the access:
export KUBECONFIG=`pwd`/kubeconfig kubectl get node
Note that you should always use
pwd/ so that a full path is set, and you can change directory if you wish.
Advanced KUBECONFIG options
You can also merge the remote config into your main KUBECONFIG file
$HOME/.kube/config, then use
kubectl config get-contexts or
kubectx to manage it.
The default "context" name for the remote k3s cluster is
default, however you can override this as below.
k3sup install \ --ip $IP \ --user $USER \ --merge \ --local-path $HOME/.kube/config \ --context my-k3s
Here we set a context of
my-k3s and also merge into our main local
KUBECONFIG file, so we could run
kubectl config set-context my-k3s or
😸 Join some agents to your Kubernetes server
Let's say that you have a server, and have already run the following:
export SERVER_IP=192.168.0.100 export USER=root k3sup install --ip $SERVER_IP --user $USER
Next join one or more
agents to the cluster:
export AGENT_IP=192.168.0.101 export SERVER_IP=192.168.0.100 export USER=root k3sup join --ip $AGENT_IP --server-ip $SERVER_IP --user $USER
That's all, so with the above command you can have a two-node cluster up and running, whether that's using VMs on-premises, using Raspberry Pis, 64-bit ARM or even cloud VMs on EC2.
Create a multi-master (HA) setup
As of k3s 1.0 a HA multi-master configuration is available through dqlite. A quorum of masters will be required, which means having at least three nodes.
- Initialize the cluster with the first server
export SERVER_IP=192.168.0.100 export USER=root k3sup install \ --ip $SERVER_IP \ --user $USER \ --cluster
- Join each additional server
Note the new
export USER=root export SERVER_IP=192.168.0.100 export NEXT_SERVER_IP=192.168.0.101 k3sup join \ --ip $NEXT_SERVER_IP \ --user $USER \ --server-user $USER \ --server-ip $SERVER_IP \ --server
kubectl get node:
kubectl get node NAME STATUS ROLES AGE VERSION paprika-gregory Ready master 8m27s v1.16.3-k3s.2 cave-sensor Ready master 27m v1.16.3-k3s.2
👨💻 Micro-tutorial for Raspberry Pi (2, 3, or 4) 🥧
In a few moments you will have Kubernetes up and running on your Raspberry Pi 2, 3 or 4. Stand by for the fastest possible install. At the end you will have a KUBECONFIG file on your local computer that you can use to access your cluster remotely.
Download etcher.io for your OS
Flash an SD card using Raspbian Lite
Enable SSH by creating an empty file named
sshin the boot partition
Generate an ssh-key if you don't already have one with
ssh-keygen(hit enter to all questions)
Find the RPi IP with
ping -c raspberrypi.local, then set
export SERVER_IP=""with the IP
Copy over your ssh key with:
k3sup install --ip $SERVER_IP --user pi
Point at the config file and get the status of the node:
export KUBECONFIG=`pwd`/kubeconfig kubectl get node -o wide
You now have
kubectl access from your laptop to your Raspberry Pi running k3s.
If you want to join some nodes, run
export IP="" for each additional RPi, followed by:
k3sup join --ip $IP --server-ip $SERVER_IP --user pi
Remember all these commands are run from your computer, not the RPi.
Now where next? I would recommend my detailed tutorial where I spend time looking at how to flash the SD card, deploy k3s, deploy OpenFaaS (for some useful microservices), and then get incoming HTTP traffic.
Try it now: Will it cluster? K3s on Raspbian
Caveats on security
If you are using public cloud, then make sure you see the notes from the Rancher team on setting up a Firewall or Security Group.
k3s docs: k3s configuration / open ports
If your ssh-key is password-protected
If the ssh-key is encrypted the first step is to try to connect to the ssh-agent. If this works, it will be used to connect to the server. If the ssh-agent is not running, the user will be prompted for the password of the ssh-key.
On most Linux systems and MacOS, ssh-agent is automatically configured and executed at login. No additional actions are required to use it.
To start the ssh-agent manually and add your key run the following commands:
eval `ssh-agent` ssh-add ~/.ssh/id_rsa
You can now just run k3sup as usual. No special parameters are necessary.
k3sup --ip $IP --user user
Buy an Insiders Subscription today via GitHub.
Blog posts & tweets
Blogs posts, tutorials, and Tweets about k3sup (
#k3sup) are appreciated. Please send a PR to the README.md file to add yours.
Contributing via GitHub
Both Issues and PRs have their own templates. Please fill out the whole template.
All commits must be signed-off as part of the Developer Certificate of Origin (DCO)
📢 What are people saying about
Five years of Raspberry Pi clusters - raspberrypi.org
Multi-master HA Kubernetes in < 5 minutes by Alex Ellis
Multi-node Kubernetes on Civo in 5 minutes flat with k3sup! - Civo Learn guide
Zero to k3s Kubeconfig in seconds on AWS EC2 with k3sup by Saiyam Pathak
k3sup mentioned on Kubernetes Podcast episode 67 by Craig Box & Adam Glick
- Also checkout the live demo
Blog post by Ruan Bekker:
Provision k3s to all the places with a awesome utility called "k3sup" by @alexellisuk. Definitely worth checking it out, its epic!
Alex - Thanks so much for all the effort you put into your tools and tutorials. My rpi homelab has been a valuable learning playground for CNCF tech thanks to you!
Trying tiny k3s on Google Cloud with k3sup by Stark & Wayne
Run Kubernetes On Your Machine with k3sup by Luc Juggery
Trying out k3sup by Geert Baeke
Creating your first Kubernetes cluster with k3sup by Daniel Persson
My 2019 In Review - Hello Open Source by Alistair Hey
Kubernetes 104: Create a 2-node k3s cluster with k3sup by Ahmed Abelsamad
My home Kubernetes cluster driven by GitOps and k3sup - by Devin Buhl
Raspberry Pi: From 0 to k3s cluster in 5 min with k3sup and Ansible - by Pablo Caderno
Kubernetes: from Zero to Hero with Kompose, Minikube, k3sup and Helm by Leon Klingele, Alexander Merker & Florian Wintel
Deploying a highly-available K3s with k3sup by Dmitriy Akulov
Checkout the Announcement tweet
Similar tools & glossary
- Kubernetes: master/slave
- k3s: server/agent
- k3s - Kubernetes as installed by
k3sup. k3s is a compliant, light-weight, multi-architecture distribution of Kubernetes. It can be used to run Kubernetes locally or remotely for development, or in edge locations.
- k3d - this tool runs a Docker container on your local laptop with k3s inside
- kind - kind can run a Kubernetes cluster within a Docker container for local development. k3s is also suitable for this purpose through
k3d. KinD is not suitable for running a remote cluster for development.
- kubeadm - a tool to create fully-loaded, production-ready Kubernetes clusters with or without high-availability (HA). Tends to be heavier-weight and slower than k3s. It is aimed at cloud VMs or bare-metal computers which means it doesn't always work well with low-powered ARM devices.
- k3v - "virtual kubernetes" - a very early PoC from the author of k3s aiming to slice up a single cluster for multiple tenants
- k3sup-multipass - a helper to launch single node k3s cluster with one command using a multipass VM and optionally proxy the ingress to localhost for easier development.
sudo required for kubectl
It's recommended that you do not run kubectl on your node, or RPi cluster, but use the KUBECONFIG file from your controller/laptop.
See also: Set kubeconfig to world-readable
Note added by Eduardo Minguez Perez
Currently there is an issue in k3s involving
iptables >= 1.8 that can affect the network communication. See the k3s issue and the corresponding kubernetes one for more information and workarounds. The issue has been observed in Debian Buster but it can affect other distributions as well.
There was an odd edge case in one of the previous versions, If you are having error with helm throwing an
error about tiller not being ready then you might want to remove the
~/.k3sup/ directory, which holds some
info used by
k3sup. Once you have removed this you should try again.
If you are having any other issues or have questions please open an issue.