Kubernetes Installation

Installation Options

To setup a Kubernetes cluster, there are several options available, each with its own advantages and use cases. Below are some of the most popular methods for installing Kubernetes:

Minikube: A local Kubernetes cluster that is easy to set up and ideal for development and testing purposes.
kubeadm: A tool that provides a simple way to create a Kubernetes cluster on any machine
k3s: A lightweight Kubernetes distribution designed for edge computing and IoT devices.
microk8s: A minimal Kubernetes distribution that is easy to install and suitable for development and testing.

In this guide, I will use k3s for the installation process. However, the steps may vary slightly depending on the method you choose. Always refer to the official documentation for the specific installation method you decide to use.

k3s Installation

Here is the documentation as well as the GitHub repository.

k3s is a lightweight Kubernetes distribution that is designed to be easy to install and operate. It is ideal for edge computing, IoT devices, and development environments.

Install Script

The easiest way to install k3s is to use the installation script provided by the k3s project. You can run the following command in your terminal:

curl -sfL https://get.k3s.io | sh -

This command will download and execute the installation script, which will set up k3s, its dependencies, and kubectl on your machine.

Make sure you have curl installed on your system before running the above command.

Terminal Output

kcserver@kcserver:~$ curl -sfL https://get.k3s.io | sh -
[sudo] password for kcserver: 
[INFO]  Finding release for channel stable
[INFO]  Using v1.34.6+k3s1 as release
[INFO]  Downloading hash https://github.com/k3s-io/k3s/releases/download/v1.34.6%2Bk3s1/sha256sum-amd64.txt
[INFO]  Downloading binary https://github.com/k3s-io/k3s/releases/download/v1.34.6%2Bk3s1/k3s
[INFO]  Verifying binary download
[INFO]  Installing k3s to /usr/local/bin/k3s
[INFO]  Skipping installation of SELinux RPM
[INFO]  Creating /usr/local/bin/kubectl symlink to k3s
[INFO]  Creating /usr/local/bin/crictl symlink to k3s
[INFO]  Skipping /usr/local/bin/ctr symlink to k3s, command exists in PATH at /usr/bin/ctr
[INFO]  Creating killall script /usr/local/bin/k3s-killall.sh
[INFO]  Creating uninstall script /usr/local/bin/k3s-uninstall.sh
[INFO]  env: Creating environment file /etc/systemd/system/k3s.service.env
[INFO]  systemd: Creating service file /etc/systemd/system/k3s.service
[INFO]  systemd: Enabling k3s unit
Created symlink /etc/systemd/system/multi-user.target.wants/k3s.service → /etc/systemd/system/k3s.service.
[INFO]  systemd: Starting k3s

Verify Installation

After the installation is complete, you can verify that k3s is running by checking the status of the service:

sudo systemctl status k3s

Terminal Output

● k3s.service - Lightweight Kubernetes
    Loaded: loaded (/etc/systemd/system/k3s.service; enabled; preset: enabled)
    Active: active (running) since Sun 2026-04-05 14:56:14 +08; 4min 11s ago
      Docs: https://k3s.io
    Process: 16564 ExecStartPre=/sbin/modprobe br_netfilter (code=exited, status=0/SUCCESS)
    Process: 16565 ExecStartPre=/sbin/modprobe overlay (code=exited, status=0/SUCCESS)
  Main PID: 16567 (k3s-server)
      Tasks: 131
    Memory: 1.4G (peak: 1.5G)
        CPU: 52.314s
    CGroup: /system.slice/k3s.service
            ├─16567 "/usr/local/bin/k3s server"
            ├─16604 "containerd "
            ├─17469 /var/lib/rancher/k3s/data/d76b59b2203578bb4cb3438338ccad2f0d3e194bef799a8957f21430b7d5f1e3/bin/containerd-shim-runc-v2 -namespace k8s.io -id 49fddc6859a2d2fbe7ff60f4bd4>
            ├─17483 /var/lib/rancher/k3s/data/d76b59b2203578bb4cb3438338ccad2f0d3e194bef799a8957f21430b7d5f1e3/bin/containerd-shim-runc-v2 -namespace k8s.io -id 39949c6a74f96b8adc19795a224>
            ├─17495 /var/lib/rancher/k3s/data/d76b59b2203578bb4cb3438338ccad2f0d3e194bef799a8957f21430b7d5f1e3/bin/containerd-shim-runc-v2 -namespace k8s.io -id 09dbfa4e70ab7c0baba199f2d9a>
            ├─18699 /var/lib/rancher/k3s/data/d76b59b2203578bb4cb3438338ccad2f0d3e194bef799a8957f21430b7d5f1e3/bin/containerd-shim-runc-v2 -namespace k8s.io -id 8ed894d3d30a49244d85dc18c88>
            └─18788 /var/lib/rancher/k3s/data/d76b59b2203578bb4cb3438338ccad2f0d3e194bef799a8957f21430b7d5f1e3/bin/containerd-shim-runc-v2 -namespace k8s.io -id c872773fae31e06fa777f93b171>

Apr 05 14:57:20 kcserver k3s[16567]: I0405 14:57:20.545650   16567 resource_quota_monitor.go:228] "QuotaMonitor created object count evaluator" logger="resourcequota-controller" resource="t>
Apr 05 14:57:20 kcserver k3s[16567]: I0405 14:57:20.545657   16567 resource_quota_monitor.go:228] "QuotaMonitor created object count evaluator" logger="resourcequota-controller" resource="s>
Apr 05 14:57:20 kcserver k3s[16567]: I0405 14:57:20.545663   16567 resource_quota_monitor.go:228] "QuotaMonitor created object count evaluator" logger="resourcequota-controller" resource="a>
Apr 05 14:57:20 kcserver k3s[16567]: I0405 14:57:20.545675   16567 resource_quota_monitor.go:228] "QuotaMonitor created object count evaluator" logger="resourcequota-controller" resource="t>
Apr 05 14:57:20 kcserver k3s[16567]: I0405 14:57:20.545681   16567 resource_quota_monitor.go:228] "QuotaMonitor created object count evaluator" logger="resourcequota-controller" resource="s>
Apr 05 14:57:20 kcserver k3s[16567]: I0405 14:57:20.545692   16567 resource_quota_monitor.go:228] "QuotaMonitor created object count evaluator" logger="resourcequota-controller" resource="i>
Apr 05 14:57:20 kcserver k3s[16567]: I0405 14:57:20.545787   16567 shared_informer.go:349] "Waiting for caches to sync" controller="resource quota"
Apr 05 14:57:20 kcserver k3s[16567]: I0405 14:57:20.746118   16567 shared_informer.go:356] "Caches are synced" controller="resource quota"
Apr 05 14:57:21 kcserver k3s[16567]: I0405 14:57:21.155050   16567 shared_informer.go:349] "Waiting for caches to sync" controller="garbage collector"
Apr 05 14:57:21 kcserver k3s[16567]: I0405 14:57:21.255550   16567 shared_informer.go:356] "Caches are synced" controller="garbage collector"

You should see output indicating that the k3s service is active and running.

You can also check the Kubernetes cluster status using kubectl:

kubectl get nodes

This command should show your node(s) in a Ready state.

If you faced the kubectl permission issue, you can refer to step 3 of this guide to resolve it.

Fix kubectl Permission Issue

You can refer this link for more details.

If you encounter a permission issue when running kubectl commands (e.g., kubectl get nodes), it may be because the k3s installation creates a kubeconfig file that is owned by root. To fix this issue, you can change the ownership of the kubeconfig file to your user.

Issue

kcserver@kcserver:~$ kubectl get nodes
WARN[0000] Unable to read /etc/rancher/k3s/k3s.yaml, please start server with --write-kubeconfig-mode or --write-kubeconfig-group to modify kube config permissions 
error: error loading config file "/etc/rancher/k3s/k3s.yaml": open /etc/rancher/k3s/k3s.yaml: permission denied

To resolve this, run the following command to change the ownership of the kubeconfig file:

Fix Permission Issue

mkdir ~/.kube 2> /dev/null
export KUBECONFIG=~/.kube/config
sudo k3s kubectl config view --raw > "$KUBECONFIG"
chmod 600 "$KUBECONFIG"

To make it persistent across reboots, you can add the above commands to your shell profile (e.g., ~/.bashrc or ~/.profile):

nano ~/.bashrc
source ~/.bashrc

Add the following lines to the end of the file:

~/.bashrc

# Set KUBECONFIG environment variable
export KUBECONFIG=~/.kube/config

After making these changes, you should be able to run kubectl commands without encountering permission issues:

Verify kubectl Access

kcserver@kcserver:~$ kubectl get nodes
NAME       STATUS   ROLES           AGE   VERSION
kcserver   Ready    control-plane   22m   v1.34.6+k3s1

​Installation Options

​k3s Installation

Install Script

Verify Installation

Fix kubectl Permission Issue

Installation Options

k3s Installation