K3S: Hands-On Projects

Deploy a Multi-Container Microservices App on K3s#

Microservices are all the rage, so let’s deploy one in K3s. We’ll set up a frontend, backend, and database, because what’s a real-world app without a tangled web of dependencies?

Define Kubernetes Deployments, Services, and ConfigMaps#

apiVersion: apps/v1
kind: Deployment
metadata:
  name: backend
spec:
  replicas: 2
  selector:
    matchLabels:
      app: backend
  template:
    metadata:
      labels:
        app: backend
    spec:
      containers:
        - name: backend
          image: myrepo/backend:latest
          ports:
            - containerPort: 5000

Expose the Application via Ingress#

After defining your deployments and services, expose the whole thing with Ingress so users can actually access it.

Set Up K3s HA Cluster with Ingress and Persistent Storage#

If your cluster goes down, you’re in trouble. A High Availability (HA) setup prevents that.

Deploy a Multi-Master K3s Cluster#

curl -sfL https://get.k3s.io | sh -s - server --cluster-init

Configure Worker Nodes to Join the HA Cluster#

curl -sfL https://get.k3s.io | K3S_URL=https://<master-ip>:6443 K3S_TOKEN=<token> sh -

Set Up Ingress Using Traefik#

Traefik is the default Ingress controller in K3s, making it easy to route traffic.

Deploy Applications with Persistent Storage#

For persistent data, define a Persistent Volume (PV) and Persistent Volume Claim (PVC).

Implement GitOps using ArgoCD on K3s#

Stop manually applying YAML files and embrace GitOps with ArgoCD.

Install ArgoCD#

kubectl create namespace argocd
kubectl apply -n argocd -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml

Deploy an Application Using ArgoCD#

argocd app create myapp --repo https://github.com/myrepo.git --path k8s-manifests --dest-server https://kubernetes.default.svc --dest-namespace default

Automate Deployments and Rollbacks#

ArgoCD continuously syncs your cluster with Git, making deployments effortless and **rollbacks