regular-nginx-deployment.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: nginx
data:
  nginx.conf: |
    events {}
    http {
      server {
          location / {
            add_header Content-Type text/plain;
            return 200 "Hello, world!";
        }
      }
    }

---
apiVersion: v1
kind: Service
metadata:
  name: nginx
spec:
  selector:
    app: nginx
  ports:
  - port: 80
    targetPort: 80

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
  labels:
    app: nginx
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.14.2
        ports:
        - containerPort: 80
        volumeMounts:
        - mountPath: /etc/nginx # mount nginx-conf volumn to /etc/nginx
          readOnly: true
          name: nginx
      volumes:
      - name: nginx
        configMap:
          name: nginx # place ConfigMap `nginx-conf` on /etc/nginx