Kubernetes demo app

k8s-demo-app.yaml

apiVersion: v1
kind: Namespace
metadata:
  name: demo-app
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: php-src
  namespace: demo-app
data:
  index.php: |
    <?php
    header("Content-Type: text/plain");
    echo 'Hello, world', PHP_EOL;
    echo 'Node: ' . getenv('MY_NODE_NAME'), PHP_EOL;
    echo 'Pod: ' . getenv('MY_POD_NAME'), PHP_EOL;
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: demo-app
  namespace: demo-app
spec:
  replicas: 4
  selector:
    matchLabels:
      app: demo-app
  template:
    metadata:
      labels:
        app: demo-app
    spec:
      volumes:
        - name: php-src
          configMap: { name: php-src }
      containers:
        - image: php:8.1-cli
          imagePullPolicy: IfNotPresent
          name: demo-app
          command: [php, -S, 0.0.0.0:3000, -t, /app]
          ports:
            - containerPort: 3000
              name: http
          volumeMounts:
            - name: php-src
              mountPath: /app
          env:
            - name: MY_NODE_NAME
              valueFrom:
                fieldRef: { fieldPath: spec.nodeName }
            - name: MY_POD_NAME
              valueFrom:
                fieldRef: { fieldPath: metadata.name }
---
apiVersion: v1
kind: Service
metadata:
  name: demo-app
  namespace: demo-app
spec:
  ports:
    - port: 80
      targetPort: http
      name: http
      protocol: TCP
  type: ClusterIP
  selector:
    app: demo-app
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: demo-app
  namespace: demo-app
  annotations:
    kubernetes.io/ingress.class: nginx
spec:
  rules:
    - http:
        paths:
          - path: /demo-app
            pathType: Prefix
            backend:
              service:
                name: demo-app
                port:
                  name: http