deployment是一个两层控制器，首先，它通过ReplicaSet 的个数来描述应用的版本；然后，它再通过ReplicaSet 的属性（比如 replicas 的值），来保证 Pod 的副本数量。如图所示：
79dcd2743645e39c96fafa6deae9d6f6.png
deployment控制指令
kubectl get deployment #{DEPLOYMENT_NAME}
kubectl edit deployment #{DEPLOYMENT_NAME}
kubectl set image deployment #{DEPLOYMENT_NAME} #{IMAGE_NAME}=#{IMAGE_NAME}:#{IMAGE_VERSION}
kubectl scale deployment #{DEPLOYMENT_NAME} --replicas=4
kubectl rollout status deployment #{DEPLOYMENT_NAME}
kubectl rollout history deployment #{DEPLOYMENT_NAME}
kubectl rollout history deployment #{DEPLOYMENT_NAME} --revision=#{ NUMBER}
kubectl rollout undo deployment #{DEPLOYMENT_NAME} --to-revision=2
kubectl rollout pause deployment #{DEPLOYMENT_NAME}
kubectl rollout resume deployment #{DEPLOYMENT_NAME}
kubectl get rs
