# 3. Deploying Applications on Your K3s Cluster - Practical Examples Once your K3s cluster is up and running, the next step is deploying applications. Whether you're experimenting with Kubernetes for the first time or testing production-ready workloads locally, K3s makes it simple and efficient. In this blog, we’ll walk through deploying a web application, adding a database service, and managing apps using Helm. By the end, you’ll have a solid understanding of deploying and monitoring applications on your K3s cluster. --- ## Preparing Your Environment Before we dive into deploying applications, let’s ensure your environment is ready: ### Prerequisites 1. A functioning K3s cluster. (If you haven’t set one up yet, check out our guide on [Getting Started with K3s](https://chatgpt.com/g/g-QFqqnKe65-techblogai/c/679539df-5cdc-8009-9a9b-f28271768bea#).) 2. `kubectl` installed and configured to communicate with your cluster. 3. Basic familiarity with Kubernetes concepts (pods, deployments, services). 4. Optional: Install **Helm** (we’ll cover this later). To verify your setup, run: ```bash kubectl get nodes ``` You should see your K3s node(s) listed with a `STATUS` of `Ready`. --- ## Example Deployments Let’s start with a simple example: deploying a web application and a database service alongside it. ### Deploying a Web Application We’ll deploy a basic NGINX-based web app using a YAML manifest. 1. **Create a file named** `web-app.yaml`: ```yaml apiVersion: apps/v1 kind: Deployment metadata: name: web-app labels: app: web-app spec: replicas: 2 selector: matchLabels: app: web-app template: metadata: labels: app: web-app spec: containers: - name: nginx image: nginx:latest ports: - containerPort: 80 --- apiVersion: v1 kind: Service metadata: name: web-app-service spec: selector: app: web-app ports: - protocol: TCP port: 80 targetPort: 80 type: LoadBalancer ``` 2. **Apply the manifest:** ```bash kubectl apply -f web-app.yaml ``` 3. **Verify the deployment:** ```bash kubectl get pods ``` You should see two pods running for the `web-app` deployment. 4. **Access the app:** Find the external IP or port assigned to the `web-app-service` using: ```bash kubectl get svc web-app-service ``` Access the web app in your browser or via `curl`. --- ### Adding a Database Service Now, let’s add a database service (e.g., MySQL) to work alongside the web app. 1. **Create a file named** `mysql.yaml`: ```yaml apiVersion: v1 kind: PersistentVolumeClaim metadata: name: mysql-pvc spec: accessModes: - ReadWriteOnce resources: requests: storage: 1Gi --- apiVersion: apps/v1 kind: Deployment metadata: name: mysql labels: app: mysql spec: replicas: 1 selector: matchLabels: app: mysql template: metadata: labels: app: mysql spec: containers: - name: mysql image: mysql:8.0 env: - name: MYSQL_ROOT_PASSWORD value: rootpassword ports: - containerPort: 3306 volumeMounts: - mountPath: /var/lib/mysql name: mysql-storage volumes: - name: mysql-storage persistentVolumeClaim: claimName: mysql-pvc --- apiVersion: v1 kind: Service metadata: name: mysql spec: ports: - port: 3306 selector: app: mysql type: ClusterIP ``` 2. **Apply the manifest:** ```bash kubectl apply -f mysql.yaml ``` 3. **Verify the deployment:** ```bash kubectl get pods ``` Ensure the MySQL pod is running and its `STATUS` is `Running`. Now your web app can connect to the MySQL service using the service name `mysql` and port `3306`. --- ## Using Helm Charts K3s is fully compatible with Helm, a powerful Kubernetes package manager. Helm simplifies deploying and managing complex applications with reusable templates. ### Installing Helm 1. **Download Helm:** ```bash curl https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3 | bash ``` 2. **Verify installation:** ```bash helm version ``` ### Deploying Applications with Helm Let's use Helm to deploy WordPress (a web app + database combo). **Note:** As of August 2025, Bitnami Helm charts have been deprecated. We'll use community-maintained alternatives. 1. **Add the Helm repo:** ```bash helm repo add presslabs https://presslabs.github.io/charts helm repo update ``` 2. **Install WordPress:** ```bash helm install my-wordpress presslabs/wordpress-operator ``` Alternatively, you can use a custom WordPress setup with the mysql:8.0 deployment we created earlier. 3. **Check the status:** ```bash helm status my-wordpress ``` 4. **Access the application:** Get the external IP of the WordPress service: ```bash kubectl get svc ``` Visit the IP in your browser to see your WordPress site in action. --- ## Monitoring and Managing Applications Monitoring your applications is critical, even in a local environment. Here are a few tools and techniques for managing your K3s workloads: ### Using `kubectl` for Basic Monitoring * Check pod status: ```bash kubectl get pods ``` * View pod logs: ```bash kubectl logs ``` ### Adding Metrics with Prometheus and Grafana **Note:** Since Bitnami charts are deprecated, we'll use community-maintained alternatives. 1. Deploy Prometheus and Grafana using Helm: ```bash # Add prometheus-community repo helm repo add prometheus-community https://prometheus-community.github.io/helm-charts helm repo add grafana https://grafana.github.io/helm-charts helm repo update # Install kube-prometheus-stack (includes both Prometheus and Grafana) helm install prometheus prometheus-community/kube-prometheus-stack # Alternatively, install Grafana separately helm install grafana grafana/grafana ``` 2. Access the Grafana dashboard and connect it to Prometheus as a data source for visualizing metrics. --- ## Conclusion Deploying applications on K3s is not only straightforward but also versatile enough to handle a wide range of use cases. Whether you’re deploying simple web apps, integrating databases, or managing complex workloads with Helm, K3s provides the tools and simplicity to get the job done. ### What’s Next? * Experiment with scaling your applications and using K3s in multi-node setups. * Explore CI/CD pipelines for automating application deployments on your K3s cluster. * Dive deeper into monitoring tools like Prometheus, Grafana, and Loki for a robust observability stack. Have questions or cool deployment ideas? Let us know in the comments below!