A pod is the smallest execution unit in Kubernetes. A Kubernetes pod is a collection of one or more Linux® containers, and is the smallest unit of a Kubernetes application. A pod encapsulates one or more applications. Pods are ephemeral by nature, if a pod (or the node it executes on) fails, Kubernetes can automatically create a new replica of that pod to continue operations.  Pods include one or more containers (such as Docker containers) Pods represent the processes running on a cluster Any given

API Server Its process the incoming API request from UI/CLI It Uses RESTAPI Controller Controls the Kubernetes cluster Kubernetes include the Endpoints Controller, Replication Controller, and Namespace Controller observes the state of the cluster scheduler Schedules Pods Scheduler maintains the work Cluser store permanent storage for Cluster config

The components of K8s worker node are1. kubelet – Kublet is the main K8s agent. It instantiate the pods in the node(only instantiate not create). It helps to register nodes with cluster. Its always watch the api server.It decides who is the master.10255 is the endpoint.2. kube-proxy – Its support for K8s networking. It assigns the ip address for the pods. Each pods inside a node will have same ip address. Load balances across all pods in a service. kube-proxy

In a Kubernetes cluster, we package our application and give it to the “Master”.Master will distribute it to the nodes (minions) which do the actual work. In the Master (representation above), there is a Control plane which has 4 components: API ServerActs as the entry point to the control plane.It exposes a REST API which consumes JSON files that has the application definition and state defined.Master checks the JSON file and pass the task onto one of the nodes in

A pod is the smallest execution unit 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.  Pods can communicate with each other by using another pods IP address or by referencing a resource that resides in another pod. Pods are created by workload resources called controllers, which manage rollout, replication, and health of pods in the cluster.

kubelet : This component ensure that containers are running in the podkube-proxy : This the network proxy that is running on each nodeDocker or any container runtime : this will run the docker/ any other container

API Server – It serves as the component where the kubernetes receives the input from the external application or end user. etcd Cluster – It serves as the brain of the kubernetes where the information are stored as a key value pair. kube-scheduler It always run in the background. It is where the pods runtime are schedules. Control Manager It is responsible for running multiple distinct applications

a) Kubelete Main Kubernetes agent Registers node with cluster (decide who is the master node) Watches api server Instantiates the pods ( not creating the pod) Reports back to master Expose endpoint on 10255 b) kube-proxy Manages the kubernetes networking Assigning pod IP address (indirectly) All containers in a pod share a single IP Load balances across all pods in service Can use different network plugins/drivers like calico (CNI plugins) c) Container Engine Container Management Pulling images start/stop the containers

Write down 10 features of Kubernetes with image? Storage orchestration Auto scaling Load balancing Self healing Container grouping using pod Automate roll backs What are the components of Kubernetes master and explain each component’s function? Apiserver: exposes REST APIs. This is the entry point to the k8s cluster. API server access JSON data via manifest file Cluster store: Stores cluster state and configurations. Controller manager: Controller of controllers like node controller, namespace controller, etc. Each controller has its own responsibilities

Below are the main components found on a (worker) node: kubelet – the main service on a node, regularly taking in new or modified pod specifications (primarily through the kube-apiserver) and ensuring that pods and their containers are healthy and running in the desired state. This component also reports to the master on the health of the host where it is running. kube-proxy – a proxy service that runs on each worker node to deal with individual host subnetting and expose services

kubelet 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. kube-proxy Kube-proxy is a network proxy that runs on each node in your cluster. 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. container runtime like docker ctr

kubernetes simplifies the data ware house into a cluster, which can operate via a laptop kubernetes help us to scale up our application so fast

Atomic Unit of kubernetes Pod contains one or more containers A node can have multiple pods pods have few states – pending, running, succeeded/failed pods are ephemeral

API Server – provides all the operation on cluster using the API. Control Manager – regulates the state of cluster and performs a task. Cluster Store – stores the configuration information which can be used by each of the nodes Scheduler – distributes the workload.

The Kubernetes master runs the Scheduler, Controller Manager, API Server and etcd components and is responsible for managing the Kubernetes cluster. Etcd Etcd is a distributed, consistent key-value store used for configuration management, service discovery, and coordinating distributed work. API Server When you interact with your Kubernetes cluster using the kubectl command-line interface, we are actually communicating with the master API Server component. Scheduler The Scheduler watches for unscheduled pods and binds them to nodes via the /binding pod subresource API, according to

Kubernetes master is the in charge of the cluster. Kuberenetes master should be of linux 64 based. The K8’s master have 4 components. They are1. api-server- Server of API’s. It contains all the APIs provided by K8s. It act as the front-end to the control panel, we access via REST API. Similar to ears in human body, it receive the requests2. cluster store – All the requests / data stored in cluster store. etcd is the storage unit use by

It is the smallest unit in kubernetes world Pod contain a self sufficient unit, like network It has a life cycle- pending, running , succeded/failed

docker – which builds and run the container. kubelet – A service for communication with etcd etc. kube-proxy – it is resposible for managing network. it makes the ports available to external.

API Server : The apis to communicate with outside world and between components. It provides api for all the operationsetcd : it is a data store used by Kubernetes to store the config data. All the communication to etcd is via api server Controller Manager: It runs in a loop to check teh state of each node Scheduler: this is the service which manages teh workload of nodes