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kubernetes 1 Basic Conception
kubernetes Basic Conception

Node:

A computer (real or virtual) where your apps run.

Container:

Docker-like Container

Pod:

A group of one or more containers that work together. Pods are the smallest thing you can run in Kubernetes.

Controller:

A helper that makes sure your apps are running the way you want. If something breaks, it tries to fix it.

Deployment

A boss for your Pods. It controls how many Pods to run, how to update them, and how to roll back if something goes wrong.

Service

A stable way to access your Pods. Even if Pods change, the Service stays the same.

Label

A name tag you put on things to organize or find them easily.

Namespace

A way to separate and organize stuff in your cluster. Like folders on your computer.
e.g. dev/test/staging
Some system namespaces:

  • default
  • kube-node-lease
  • kube-public
  • kube-system

Ingress

Load balancer / Nginx

Volume

Storage

ConfigMap

A place to store app settings (like text files with config values).

Secret

Like ConfigMap, but for sensitive stuff (passwords, API keys). Stored safely.

etcd

A brain that remembers everything about your cluster.

APIServer

The front desk of Kubernetes. It takes your commands and passes them to the right place.

Controller-manager

The one who runs all the controllers (helpers) in the background.

Scheduler

Finds the best computer (Node) to run each Pod.

kuberctl

The tool you use to talk to Kubernetes from the command line.

kubelet

Runs on each computer (Node) and makes sure the containers are up and running.

kube-proxy

Handles network traffic so Pods can talk to each other and to the outside world.