Deploy your first app

This guide takes a container image and gets it running on Kubernetes as a Deployment, then exposes it inside the cluster with a Service. The steps work on any conformant cluster; we use a paasbox cluster as the example.

1. Point kubectl at your cluster

Download your cluster’s kubeconfig and confirm you can reach it:

export KUBECONFIG=~/Downloads/paasbox-kubeconfig.yaml
kubectl get nodes

You should see your nodes listed as Ready.

2. Create a namespace

Keep your app’s objects together in their own namespace:

kubectl create namespace demo

3. Deploy the app

A Deployment runs and supervises your container, replacing Pods that crash or get rescheduled. Save this as deployment.yaml:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: web
  namespace: demo
spec:
  replicas: 2
  selector:
    matchLabels: { app: web }
  template:
    metadata:
      labels: { app: web }
    spec:
      containers:
        - name: web
          image: nginxdemos/hello:plain-text
          ports:
            - containerPort: 80
          resources:
            requests: { cpu: 50m, memory: 64Mi }
            limits: { cpu: 250m, memory: 128Mi }

Apply it and watch the Pods come up:

kubectl apply -f deployment.yaml
kubectl -n demo get pods -w

Always set resource requests. They tell the scheduler how much CPU and memory your Pods need, which is what lets the cluster pack workloads efficiently — and on paasbox, that efficiency is where your savings come from.

4. Expose it with a Service

A Service gives your Pods one stable address inside the cluster, load-balanced across replicas:

apiVersion: v1
kind: Service
metadata:
  name: web
  namespace: demo
spec:
  selector: { app: web }
  ports:
    - port: 80
      targetPort: 80

kubectl apply -f service.yaml

5. Try it

Port-forward the Service to your machine and hit it:

kubectl -n demo port-forward service/web 8080:80
# in another terminal:
curl localhost:8080

You should get a response from the app. 🎉

Next steps

• Run more copies and let the cluster scale them: Scale & autoscale workloads.
• To serve traffic from the public internet, add an Ingress (or a Gateway) in front of the Service — a future guide will cover this end to end.

Clean up

kubectl delete namespace demo