Debug School: Rahul

Services

Rahul — Mon, 25 Sep 2023 07:30:37 +0000

what is Services

Services are the resources which help to load balance the traffic route to the pods. Services works when the mapping defined in the Selector of service and labels defined at the pod is same.

Types of Services:

1) ClusterIP- This is a default one. This works within the cluster.
2) NodePort- This is the service exposed at the Node level. This can be accessed from outside the cluster
3) LoadBalancer- This service will be created by kubernetes in conjuction with underlying environment. It can be AWS or Azure. This service has to add all the nodes where balancing needs to be done.

Assignment 2

Rahul — Fri, 22 Sep 2023 11:55:53 +0000

What is Namespaces? Explain with Image

Namespace is a logical separation of resources within the cluster so that if multiple teams are using the same cluster.
In this image there are 3 namespaces shown:
1) Default: This is a default namespace and all those resources which are deployed without any namespace will be deployed here.
2) There are two other namespace viz: dev and qa created here

What is Pod? Explain with Image

Image is an atomic deployment which provide isolated environment to run your containers.
You can run multiple containers within pod. In the current image there are 2 containers deployed within the same pod.
Cluster manages the lifecycle of pods.

What is ReplicaSets? Explain with Image

A ReplicaSet is a resource that ensures there is always a stable set of running pods for a specific workload.
If due to some issues, few pods goes down it will help bring them back so that at any point of time desired state is met

What is Deployment? Explain with Image
A Deployment is a declarative way to updates Pods and ReplicaSets.

Kubernetes Introduction

Rahul — Thu, 21 Sep 2023 09:15:08 +0000

What is Kubernetes?

Kubernetes is an open source tool from CNCF community which is used to deploy containers (work) and manage their lifecycle.

Why do we need it?

Kubernetes is helping us to overcome some of the challenges brought by containerization w.r.t our scaling architecture. For Example: Port conflicts if multiple instances of application requires same port for communication.

How it works?

Kubernetes creates a separate Pod or cluster overlay network which helps multiple containers deployed in same node or multiple nodes to talk directly.
It uses Host network to communicate between Minnions and Master nodes. Worker Nodes chooses master during registration and exchange certificate during initial registration process and that is how they establish a relation.
Scheduler decides which node to be picked to instantiate pod
Any external request (Json or yaml) target to API server (via network load balancer) will be sent to the worker node.

What are the components of Master?

There are 4 major components to consider any node to be MASTER. Below are those:
1) Api server
2) Controlloer
3) Storage
4) Scheduler

What are the components of Worker?

1) Kubelet
2) Kube proxy