Control Plane The clusters are controlled by the component plane. The scheduling, instantiating a pod and deployments are handled by the control plane. kubelet The process responsible for communication between the Kubernetes control plane and the node. Container Runtime A runtime responsible for the managing the container.

Pod is the atomic unit of scheduler in K8s. Pods contains one or more containers, at least one. K8s(kubelet) will instantiate pods. Pod is running as long the container inside is running. Life cycle of pod – Pending, Running, Succeded/ Failed Pods will communicate with each other through a pod network – inter pod communication. If the pods are in same node, it will communicate via localhost. We can’t get the same pod again. We can get the similar pod.

API Server: All the incoming/outgoing communication with Kubernetes cluster happening through API Server. APIServer is a RESTful server. Workstations/Client uses Kubectl tool for communicating with the API Server. API Server expects the inputs in JSON format. All the communication with the Master node worker nodes are also happening through API Server. Scheduler/Controller Manager uses API Server for all the communications with the worker nodes. Authentication and authorization. Etcd: This is the storage mechanism Kubernetes Master node has. All the details

Kubernetes worker or Minion or Node runs the actual workload.It reports the status of the application to the cluster “Master” and also listens to any change in the application definition on the Master. It has three components: KubeletRegisters a node with its clusterIt watches the AI server for changes in the definition of the applicationinstantiates podsreports the health status of the pods to the masterendpoint is 10255 Kube proxy Handles the networking for the KubernetesAll containers in a pod shares

kubelet – This is the main K8s agent. It inistantiates the pods in the node. It helps to register nodes with cluster. Its always watch the api server. kube-proxy – Its support for K8s networking. It provide ip address for the pods. Each pods inside a node will have same ip address. kube-proxy rules All pods communicate with each other on all nodes. All nodes communicate with all pods No network address translation – NAT pod – It is an

Kubelet: Resides in each worker nodes. Registers the node to the master node. Instantiate the Pods. Container Runtime (Docker): For managing and running the containers. Kube-Proxy: It is a nw proxy. Implements nw rules on PODS. Fecilitate the communication with in the cluster and outside the cluster. All the networking related supports are done by this component. Can say like a virtual n/w card for the nodes. Responsible for assigning IP addresses and all.

Container Its a the application/env we need to managed by K8s Kubelet  kubelet is responsible for starting, stopping the containers in pods, Ensure the stable running in the desired state Runs the Kubernetes nodes Kube-proxy service for network proxy makes communications between pods, containers, and nodes

API server – It contains all the APIs provided by K8s. It acts as the front-end, we access via REST. It is like ears in human body, it receive the things. Cluster store – All the requests / data stored in cluster store. etcd is the storage unit use by k8s. It is like brain in human body. There is only one cluster store in a master. Controller Manager – It is manager of all the controllers. One controller is

PODS are the atomic unit of scheduling in K8sDocker manages container – VMware manages VM & K8s manages PODsIt is our application or the serviceIt is the basic unit of workNo pod is ever redeployed(Ephemeral) (ie, we can’t get the same pod again. We can get the similar pod.)Pod is running as long the container inside is running.Pods contains one or more containers, at least one.Kubelet will instantiate pods.Pod is running as long the container inside is running.Pods will communicate

K8s can manage the scalability challenge bring by containers. K8s runs many containers as a cluster K8s is a container orchestrator K8s provide the desired state – we desired to have 1000 containers K8s is self maintaining – self healing Auto rollback Auto scaling K8s managing load balancing K8s absorb changes K8s provide very speed deployment K8s enhance the productivity by reducing the dependency K8s provide the security improvement

Kubelet Kube-proxy pod container

Pod is the basic unit of work It is application or service Pod is an atomic unit of scheduling in Node Kubernetes manages pod and not container Kubernetes job is to keep the pods running based on desired state State is the pod up and running Health is the application in the pod running Pod shares the same resource with all containers in it Pod shares the same IP to all containers in it Preferred approach is one container in

atomic unit of schedulingall container in pod share the pod environment. anything attached to pod, all container can use it.it can contain one or more containers.pod can have tight coupling- loose coupling.pods are atomic, you can scale the port from 1 to many.pods are the application which can access through n/w.pods contain container. and runs as long as container run.multi container pods – main container and side car container.pod lifecycle: phase: pending –> phase: running –> phase: succeeded/failed.inter pod communication

kubelet: just like a slave. the main kubernetes agent. register node with cluster- master approves it. watches api server.kubelet will talk to api server with health status.instantiate pods – not creation. pod is the logical unit of cluster. exposes end points on 10255.container engine: does container management. ex:dockerkube proxy: it assign pod ip address, all containers in a pod shared a single ip. load balances across all pods in a service.

API server : It is the front end for the Kubernetes control plane, exposes the Kubernetes API. All other components interact with api server. SchedulerThis is one of the key components of Kubernetes master. It is a service in master responsible for distributing the workload. Controller ManagerControls the Kubernetes cluster. It includes the Endpoints Controller, Replication Controller, and Namespace Controller etc etcd : Consistent and highly-available key value store used as Kubernetes’ backing store for all cluster data

api server: all the feature available at api server. , front end to control plane. anything want to master , can send to api server.it can be using http, it consumes json file. internally it communicates with each other.cluster store:any req is send is stored here. internal communication(worker to master etc.) also stored here. it uses etcd (open source) to store.it should exist in etcd- source of truth.controller manager: collection of controller. node controller(all the monitoring activities), endpoints controller. watches

k8s is container orchestration toolworkload placement ,k8s helping infrastructure abstractionhelp to manage desired stateself healing, replace with desired stateautomatic rollback/rollouts – rollback the feature / versionauto scaling – 5 container to 50 container can be doneload balancing of container/podshigh speed of deployment. upgrade/ability to rollbackstorage orchestration.

Pods Pods are the smallest deployable units of computing that you can create and manage in Kubernetes. A Pod (as in a pod of whales or pea pod) is a group of one or more containers, with shared storage and network resources, and a specification for how to run the containers. A Pod’s contents are always co-located and co-scheduled, and run in a shared context. A Pod models an application-specific “logical host”: it contains one or more application containers which are relatively tightly coupled.