Author : HASSAN MD TAREQ | Updated : 2021/04/13

Container

A container is a loosely isolated environment that allows us to build and run software packages. These software packages include the code and all dependencies to run applications quickly and reliably on any computing environment.

Container image

Docker

Kubernetes

Kubernetes abstracts away complex container management tasks, and provides you with declarative configuration to orchestrate containers in different computing environments.

Kubernetes Cluster

Node

Typically you have several nodes in a cluster, but you might have only one node.

Master node

Worker nodes

Kubernates Compnents or Kubernates Resources

Pod

Endpoint

Service

Control Plane

Kubernetes Cluster Compnents

The master node runs Control Plane Components, and the worker nodes run Node Components.

ReplicaSet

A Replica Set’s purpose is to maintain a stable set of replica Pods running at any given time.

Desired State

Example: thermostat
When you set the temperature, that’s telling the thermostat about your desired state. The actual room temperature is the current state. The thermostat acts to bring the current state closer to the desired state, by turning equipment on or off.

Desired State in K8s
In Kubernetes, controllers are control loops that watch the state of your cluster, then make or request changes where needed. Each controller tries to move the current cluster state closer to the desired state.

Deployment

Dashboard

kubectl

Manifest File

Namespace