Echo Server Deployment

echo-server.yml

apiVersion: v1
kind: Namespace
metadata:
  name: echoserver
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: echoserver
  namespace: echoserver
spec:
  replicas: 3
  template:
    metadata:
      labels:
        app: echoserver
    spec:
      containers:
      - image: gcr.io/google_containers/echoserver:1.0
        imagePullPolicy: Always
        name: echoserver
        ports:
        - containerPort: 8080
---
apiVersion: v1
kind: Service
metadata:
  name: echoserver
  namespace: echoserver
spec:
  ports:
  - port: 80
    targetPort: 8080
    protocol: TCP
  selector:
    app: echoserver
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: echoserver
  namespace: echoserver
  annotations:
    kubernetes.io/ingress.class: "nginx"
spec:
  rules:
  - host: echo.example.com
    http:
      paths:
      - path: /
        backend:
          serviceName: echoserver
          servicePort: 80

FYI, I also had to add

  selector:
    matchLabels:
      app: echoserver

on a Kubernetes 1.18 cluster.