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Running K3s on Raspberry Pi
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Introduction
Preparing Your Raspberry Pi Cluster
Installing K3s
Using Your K3s Cluster
Real-World Deployments
Advanced Topics
Final Project
Summary
Deploying Apps
Learn how to deploy real-world applications on your K3s cluster using Deployments, Services, and Ingress.
By Kevin McAleer, 2 Minutes
Page last updated May 24, 2025
Now that your K3s cluster is running and accessible via services and ingress, it’s time to deploy a real-world application.
In this lesson, you’ll deploy a simple web app with a backing Redis database using Deployments, Services, and an Ingress rule.
🧩 Example App: Python + Redis
We’ll deploy:
- A Flask web app (
web) - A Redis database (
redis)
These will be connected using environment variables and services.
📁 Step 1: Create Deployment YAML
Create a file called webapp.yaml:
apiVersion: apps/v1
kind: Deployment
metadata:
name: web
spec:
replicas: 1
selector:
matchLabels:
app: web
template:
metadata:
labels:
app: web
spec:
containers:
- name: web
image: kevdev/web-redis-demo:latest
ports:
- containerPort: 5000
env:
- name: REDIS_HOST
value: redis
---
apiVersion: v1
kind: Service
metadata:
name: web
spec:
selector:
app: web
ports:
- protocol: TCP
port: 80
targetPort: 5000
This assumes you have a Docker image like kevdev/web-redis-demo on Docker Hub — update it with your own image if needed.
🧱 Step 2: Add Redis Deployment
Append this to the same file or create a separate redis.yaml:
apiVersion: apps/v1
kind: Deployment
metadata:
name: redis
spec:
replicas: 1
selector:
matchLabels:
app: redis
template:
metadata:
labels:
app: redis
spec:
containers:
- name: redis
image: redis:alpine
---
apiVersion: v1
kind: Service
metadata:
name: redis
spec:
selector:
app: redis
ports:
- protocol: TCP
port: 6379
🚀 Step 3: Apply to the Cluster
kubectl apply -f webapp.yaml
kubectl apply -f redis.yaml
Verify everything is running:
kubectl get pods
kubectl get svc
🌐 Step 4: Add Ingress
Create a file called webapp-ingress.yaml:
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: web-ingress
annotations:
traefik.ingress.kubernetes.io/router.entrypoints: web
spec:
rules:
- host: web.local
http:
paths:
- path: /
pathType: Prefix
backend:
service:
name: web
port:
number: 80
Apply it:
kubectl apply -f webapp-ingress.yaml
Add this to /etc/hosts on your local machine:
192.168.1.100 web.local
Visit http://web.local in your browser!
🧪 Optional: Scale Your App
kubectl scale deployment web --replicas=3
See the load balancing in action (especially with Ingress).
✅ Summary
You now know how to:
- Deploy multi-container apps using YAML
- Connect services via internal DNS
- Expose apps using Ingress
- Scale deployments with one command
Next up: Using Helm
You can use the arrows ← → on your keyboard to navigate between lessons.
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