Concept Overview

What is Kubernetes

学习内容：What is Kubernetes

Kubernetes的优势：

• Service discovery and load balancing/服务发现、负载均衡
• Storage orchestration/存储编排
• Automated rollouts and rollbacks/自动部署和回滚
• Automatic bin packing/自动包装
• Self-healing/自我修复
• Secret and configuration management/密钥和配置管理
• Horizontal scaling/水平伸缩

Kubernetes Components

from Kubernetes Components

• Master Components
  • Master components provide the cluster’s control plane.
  • Typically, do not run user containers on this machine.
  • etcd: Consistent and highly-available key value store used as Kubernetes’ backing store for all cluster data.
  • kube-scheduler: Component on the master that watches newly created pods that have no node assigned, and selects a node for them to run on.
• Node Components
  • Node components run on every node, maintaining running pods and providing the Kubernetes runtime environment.
  • kubelet: An agent that runs on each node in the cluster. It makes sure that containers are running in a pod.
  • kube-proxy:
    • kube-proxy maintains network rules on nodes.
    • kube-proxy is a network proxy that runs on each node in your cluster, implementing part of the Kubernetes Service concept.
  • Container Runtime: The container runtime is the software that is responsible for running containers.
• Addons
  • Addons use Kubernetes resources (DaemonSet , Deployment , etc) to implement cluster features. Because these are providing cluster-level features, namespaced resources for addons belong within the kube-system namespace.
  • DNS: Cluster DNS is a DNS server, in addition to the other DNS server(s) in your environment, which serves DNS records for Kubernetes services.
  • Web UI (Dashboard): Dashboard is a general purpose, web-based UI for Kubernetes clusters
  • Container Resource Monitoring
  • Cluster-level Logging