K3s Has a Free Lightweight Kubernetes That Runs on a Raspberry Pi

#kubernetes #k3s #devops #selfhosted

Kubernetes needs 4GB RAM minimum. K3s runs a full Kubernetes cluster in 512MB — certified by CNCF, production-ready, and packaged as a single 70MB binary.

What K3s Removes

K3s strips Kubernetes of components most people do not need:

Legacy cloud provider plugins
Non-default storage drivers
Docker dependency (uses containerd)
Heavy alpha/experimental features

What remains is 100% Kubernetes API compatible — your kubectl commands, Helm charts, and manifests work unchanged.

Install (30 Seconds)

# Server (master node)
curl -sfL https://get.k3s.io | sh -

# Check it works
kubectl get nodes
# NAME    STATUS   ROLES                  AGE   VERSION
# node1   Ready    control-plane,master   30s   v1.30+k3s1

One command. Full Kubernetes. Under 30 seconds.

Add Worker Nodes

# Get the token from the server
cat /var/lib/rancher/k3s/server/node-token

# On worker nodes
curl -sfL https://get.k3s.io | K3S_URL=https://server-ip:6443 K3S_TOKEN=your-token sh -

What Is Included

K3s bundles everything you need:

Component	Included	Standalone alternative
Container runtime	containerd	Docker
CNI (networking)	Flannel	Calico, Cilium
Ingress	Traefik	Nginx Ingress
Load Balancer	ServiceLB	MetalLB
Storage	Local-path	Longhorn
DNS	CoreDNS	—
Helm controller	Yes	—

Deploy Your App

# app.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-api
spec:
  replicas: 3
  selector:
    matchLabels:
      app: my-api
  template:
    metadata:
      labels:
        app: my-api
    spec:
      containers:
        - name: api
          image: my-registry/my-api:latest
          ports:
            - containerPort: 3000
          resources:
            requests:
              memory: "64Mi"
              cpu: "100m"
            limits:
              memory: "128Mi"
              cpu: "250m"
---
apiVersion: v1
kind: Service
metadata:
  name: my-api
spec:
  type: ClusterIP
  ports:
    - port: 80
      targetPort: 3000
  selector:
    app: my-api
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: my-api
spec:
  rules:
    - host: api.example.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: my-api
                port:
                  number: 80

kubectl apply -f app.yaml

Resource Usage

	K8s (kubeadm)	K3s	K0s
Server RAM	2-4 GB	512 MB	1 GB
Binary size	~300 MB	70 MB	170 MB
Startup time	2-5 min	30 sec	1 min
Install complexity	High	One command	One command
CNCF certified	Yes	Yes	Yes

Perfect For

Edge computing — IoT devices, retail locations
Development — local k8s that does not eat your RAM
Raspberry Pi clusters — ARM64 support built-in
CI/CD — spin up k8s for integration tests
Home lab — run production workloads on old hardware
Small businesses — production k8s on a $5 VPS

Need Kubernetes infrastructure or automation? I build DevOps tools and data solutions. Email spinov001@gmail.com or check my Apify tools.

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