apiVersion: apps/v1 # for versions before 1.9.0 use apps/v1beta2
kind: Deployment
metadata:
  name: nginx
  labels:
    app: nginx     
spec:
  selector:
    matchLabels:
      app: nginx
  replicas: 1 # tells deployment to run 2 pods matching the template
  template: # create pods using pod definition in this template
    metadata:
      # unlike pod-nginx.yaml, the name is not included in the meta data as a unique name is
      # generated from the deployment name
      labels:
        app: nginx     
    spec:
      containers:
        - name: nginx
          image: nginx:alpine
          ports:
          - containerPort: 80        
          volumeMounts:
            - name: nginx-config
              mountPath: /etc/nginx/nginx.conf
              subPath: nginx.conf
      volumes:
        - name: nginx-config
          configMap:
            name: confnginx