Kubernetes --- ReplicationController resource controllers, ReplicaSet and Deployment

1.ReplicationController and ReplicaSet Introduction

　　The main role of RC (ReplicationController) is used to ensure that the number of copies of copies of the number of container application is always maintained at a user-defined. That is, if there is an abnormal exit the container will automatically create a new Pod in place; and if the abnormal extra container will automatically recover Kubernetes 

　　The official recommended RS (Replicaset) replace RC (ReplicationController) deployment, RS no essential difference with the RC, but not the same name, and a set of support RS-style selector

⒉ReplicaSet resource file example

apiVersion: extensions/v1beta1
kind: ReplicaSet 
metadata:
  name: frontend 
spec:
  replicas: 3 # There are three copies
  selector: # tag selector
    matchLabels:
      tier: frontend 
  template: # Template
    metadata:
      1abels:
        tier: frontend 
    spec:
      containers:
      - name: php-redis 
        image: gcr.io/google_samples/gb-frontend:v3 
        env:
        - name: GET_HOSTS_FROM 
          value:dns 
        ports:
        - containerPort: 80

⒊Deployment Introduction