Control plane: manage the working nodes and Pod nodes in the cluster
: a group of working machines, called nodes, each cluster has at least one node
pod: the node will be hosted pod, podwhich is the basis of all business types and the smallest unit level of K8S management . It is a combination of one or more containers
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Next, let’s talk about the components in the control plane
Control Plane Components
Control the overall situation, such as creating pod, scheduling resources, etc.
1. to apiserver
Exposes the Kubernetes API responsible for accepting requests
2.kube-scheduler
Responsible for scheduling nodes and monitoring nodes
3.etcd
A consistent and highly available key-value store that serves as the backend database for all Kubernetes cluster data.
4.kube-controller-manager
Responsible for running the controller
controller
- Node Controller: responsible for notifying and responding when a node fails
- Job Controller: monitors Job objects representing one-off tasks, then creates Pods to run those tasks to completion
- Endpoint Slice controller: Populates the Endpoint Slice object (to provide links between Services and Pods).
- Service Account Controller (ServiceAccount controller): Create a default service account (ServiceAccount) for a new namespace.
5.cloud-controller-manager
The cloud controller manager, which connects the cluster to the cloud provider's API and separates the components that interact with that cloud platform from the components that interact with your cluster.
Node (Node) component
The node component will run on each node, responsible for maintaining the running Pod and providing the Kubernetes operating environment
1. Kubelet
Kubelet will run on each node in the cluster to ensure that each container is running pod, and kubelet will only manage containers created by k8s
2.kube-proxy (proxy)
Refers to the agent running on each node in the cluster, maintaining the network rules on the node
3. Container Runtime
The software responsible for running the container
Addons
DNS
Cluster DNS is a DNS server that works with other DNS servers in the environment to provide DNS records for Kubernetes services.
web interface
Users can manage and troubleshoot applications running in the cluster as well as the cluster itself