Deploying Your First App

This walkthrough deploys a simple web application to the cluster and makes it publicly accessible at a *.nstsdc.org URL.

Prerequisites

• SSH access to nst-n1
• Basic familiarity with kubectl

What we will deploy

containous/whoami — a tiny HTTP server that responds with information about itself (hostname, IP, headers). It is the standard test image for verifying ingress routing.

Step 1: Create a namespace

Namespaces isolate workloads. Create one for your app:

kubectl create namespace apps

If the apps namespace already exists, this is fine — it will just tell you it already exists.

Step 2: Create a Deployment

A Deployment manages your application pods — how many replicas to run, which image to use, and how to update them.

kubectl -n apps create deployment whoami --image=containous/whoami

Verify the pod is running:

kubectl -n apps get pods

You should see something like:

NAME                      READY   STATUS    RESTARTS   AGE
whoami-6b9f5d5897-abc12   1/1     Running   0          10s

Step 3: Create a Service

A Service gives your deployment a stable internal address. Other things in the cluster (like Traefik) use the Service to reach your pods.

kubectl -n apps expose deployment whoami --port=80

Verify:

kubectl -n apps get svc whoami

Step 4: Create an Ingress

The Ingress tells Traefik to route traffic for a specific hostname to your Service.

Create a file called whoami-ingress.yaml:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: whoami-ing
  namespace: apps
spec:
  ingressClassName: traefik
  rules:
    - host: whoami.nstsdc.org
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: whoami
                port:
                  number: 80

Apply it:

kubectl apply -f whoami-ingress.yaml

Step 5: Test locally

Before testing from the internet, verify routing works on the node itself:

curl -i -H "Host: whoami.nstsdc.org" http://127.0.0.1

You should see a 200 response with details about the whoami container.

Step 6: Test from the internet

Open your browser and visit:

http://whoami.nstsdc.org

The request travels: your browser → Cloudflare → tunnel → nst-n1 → Traefik → whoami Service → whoami Pod.

What just happened

You created three Kubernetes resources:

1. Deployment — runs one or more copies of your container image
2. Service — provides a stable ClusterIP and DNS name for the deployment
3. Ingress — maps an external hostname to the Service

This is the fundamental pattern for every HTTP app on the cluster. The hostname, image, and port change; the pattern stays the same.

Cleanup

To remove everything:

kubectl -n apps delete ingress whoami-ing
kubectl -n apps delete svc whoami
kubectl -n apps delete deployment whoami

Next steps

• Get a public URL for your own app
• Debug a broken pod