What are main components of K8s?

Here is hierarchy of components:

  • Cluster: 
    • Node: Cluster have set of Nodes
      • Node can be of two type:
        • Master Node
        • Worker Node
          • POD: Work Node run container instances in form of POD.

What is a Node?

A node is a machine – physical or virtual – on which Kubernetes is installed.

What is a Cluster?

A cluster is a set of nodes grouped together. 

What is Master Node?

A cluster have at-least one Master Node.

Master keeps a look over the worker nodes in the cluster and is responsible for the actual orchestration of containers on the worker nodes.

Master GIF by memecandy

When we say look over, we means Master Node:

  • Monitors
  • Controls/Manage
  • Schedule Containers
  • Ensure Replication of Containers
  • Ensure Scaling of Containers
  • Expose APIs

What is the role of Worker Node?

Worker Node Functionality

  • Runs Containers
  • Contains Container Runtime
  • Accept request to run/destroy containers
  • Also called as Minions

What is a POD?

  • POD is smallest Deployable Unit
  • Containers are not directly deployed in Kubernetes on Worker node but deployed as Pod
  • Single Pod can contain one or more Containers.
  • Characteristics of containers deployed in one POD:
    • Share environment
    • Share Volumes
    • Share IP Address
    • Share lifecycle (live together, die together)
    • Scheduled on the same worker node

Rakesh Kalra

Hello, I am Rakesh Kalra. I have more than 15 years of experience working on IT projects, where I have worked on varied complexity of projects and at different levels of roles. I have tried starting my own startups, 3 of those though none of it were successful but gained so much knowledge about business, customers, and the digital world. I love to travel, spend time with my family, and read self-development books.


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