$ vi nginx-deployment.yaml

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: webapp
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx
  minReadySeconds: 5
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: webapp
        image: nginx
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 80

The previous configuration is mentioning the following things:

• The kind of file is deployed, and the name is webapp.
• The number of replicas will be two, and the name of application is nginx.
• The name of the container is webapp and the image nginx is used.
• ImagePullPolicy is IfNotPresent, meaning that the image is not present in the cluster or pulled from registry. If its there, then use that image.
• Container port is using 80.