There are two types of components are avalible for the Kubernetes.
1.Control Plane Components
2.Node Components
1.Control Plane Components
The control plane's components make global decisions about the cluster (for example, scheduling), as well as detecting and responding to cluster events (for example, starting up a new pod when a deployment's replicas field is unsatisfied).
kube-apiserver
This exposes the Kubernetes API. The API server is the front end for the Kubernetes control plane.
The example of a Kubernetes API server is kube-apiserver. kube-apiserver is designed to scale horizontally—that is, it scales by deploying more instances. Using this api You can run several instances of kube-apiserver and balance traffic between those instances.
Etcd
This is Consistent and highly-available key value store used as Kubernetes' backing store for all cluster data.If your Kubernetes cluster uses etcd as its backing store, make sure you have a backup plan for those data.
kube-scheduler
The scheduler watches for newly created Pods with no assigned node, and selects a node for them to run on.
kube-controller-manager
This runs controller processes.
Each controller runs in a separate process, but to reduce complexity, those are compiled into a single binary and run as single process.
Those controllers include.
Node controller: Responsible for noticing and responding when nodes go down.
Replication controller: Responsible for maintaining the correct number of pods for every replication controller object in the system.
Endpoints controller: Populates the Endpoints object (that is, joins Services & Pods).
The cloud controller manager lets you link your cluster into your cloud provider's API, and separates out the components that interact with that cloud platform from components that just interact with your cluster.
The cloud-controller-manager only runs controllers that are specific to your cloud provider. If you are running Kubernetes on your own premises, or in a learning environment inside your own PC, the cluster does not have a cloud controller manager.
Node components run on every node, maintaining running pods and providing the Kubernetes runtime environment.
The kubelet takes a set of PodSpecs that are provided through various mechanisms and ensures that the containers described in those PodSpecs are running and healthy.
The kubelet doesn't manage containers which were not created by Kubernetes.
kube-proxy is a network proxy that runs on each node in your cluster, implementing part of the Kubernetes Service concept.
kube-proxy maintains network rules on nodes. These network rules allow network communication to your Pods from network sessions inside or outside of your cluster.
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.
Addons are described below.
DNS
While the other addons are not strictly required, all Kubernetes clusters should have cluster DNS, as many examples rely on it.
Cluster DNS is a DNS server, in addition to the other DNS server(s) in your environment, which serves DNS records for Kubernetes services.
Containers started by Kubernetes automatically include this DNS server in their DNS searches.
Web UI (Dashboard)
The dashboard is a general-purpose, web-based UI for Kubernetes clusters.
Container Resource Monitoring
Container Resource Monitoring records generic time-series metrics about containers in a central database and provides a UI for browsing that data.
Cluster-level Logging
A cluster-level logging mechanism is responsible for saving container logs to a central log store with a search/browsing interface.
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