Debug School: Ganesha B S

Day 3 Summary

Ganesha B S — Wed, 18 Oct 2023 12:06:06 +0000

Daemon Set :

A Daemon Set is a type of workload in Kubernetes that ensures that one and only Pod runs on all nodes within a cluster, It is basically used for proxy kind of services.
Daemon Sets ensure that exactly one instance of a specified Pod is scheduled and running on each node that matches the Pod's node selector.

Jobs:

A job is something that runs the specified task using the container image provided in the template.
Once the task is completed successfully, the Job is considered finished.
Crone Jobs:
Cron Job is a resource that allows you to run Jobs at scheduled intervals.
The job is created as a one-time Job when the schedule is met and then terminated.
The Schedule field is used to specify when the job should run i.e.(schedule: "*/5 * * * *"). In this case, it runs every 5 minutes.
Config Map:
In Kubernetes, a Config Map is a resource that allows you to store configuration data separately from your application code.
Services :
Service is also known as network load balancer.
Service only send traffic to healthy pods.
Services can be accessible from outside the cluster.
It uses TCP by default and load balancing is Random load balancing by default.
Service can be configured for session affinity.
The labels of pods should be same as the selector labels of service to balance the load.
Expose command automatically take the labels from deployment and create a service and balance the load.

Node Port:

Node port create a service with cluster IP and type is node port which can be accessible from outside.
Node port is something which is used to communicate from outside to the pod.
To access the pod inside the cluster we need to give the Service IP : port and to access from outside we need to give Node IP.

Ingress Controller:

An Ingress Controller in Kubernetes is a component that manages and configures access to services within the cluster from external network traffic.
It acts as a reverse proxy, handling incoming HTTP and HTTPS traffic

Day 2 - Summary

Ganesha B S — Tue, 17 Oct 2023 11:45:48 +0000

Namespace
POD
Replication controller
Deployment

Create
Read
Update
Delete

Pods
Namespace
Nodes

Log
Attach

Replication Controller
replica set

Replicaset + controller + Versoning + Rollout + Rollback

Strategy :

Recreate
Rollingupdate

Assignment #2 What is POD

Ganesha B S — Mon, 16 Oct 2023 11:48:27 +0000

A POD is one or more container, its application service. The most basic unit of work. Unit for scheduling. A POD will have status running, exited, ready. A POD contains one or more application. POD is minion. Container resides inside the POD. There can be mutiple container in one POD, & One POd One Container design is always good.

Assignment #1

Ganesha B S — Mon, 16 Oct 2023 07:25:43 +0000

What is Kubernetes?

Kubernetes is container orchestration technology developed by Google and made as open source in 2014, managed by CNCF. This is written in Go Lang.
Kubernetes a.k.a K8's helps in managing multiple docker containers. This helps in scaling, scheduling, monitoring container orchestration.

Why Do we need Kubernetes? Explain in 10 lines

To solve our customer day to day problems, there by easing out clinicians work flows
To solve problem of High Availability
To solve problem of Scalability
Manage multiple docker hosts, run any number (1000's) containers.
Self healing automated container orchestration.
To have good Health wealth there by Happiness :-)
Runtime automated upgrade
To provide storage orchestration.

How Kubernetes Works?

Kubernetes will have Master and Worker node (minion), the master control the node as per request sent to api server. The POD which is a logical unit will have one or multiple nodes. Kubernetes creates pods and get the information about pods. It creates the required number of pods as per configuration.

Kubernetes Architecture. Explain each component with 1 one line.

API Server: This is the api server through which we can send commands to K8's master node. Collection
Cluster Store (etcd) : This acts as database stores information about pods in key value storage format.
Kube controller manager : This controls and manages commands sent api server
Kube Scheduler : Assign tasks to minions/nodes based on availability CPU memory etc.