Debug School: Yashin Jalal

Kubernetes training -SVC

Yashin Jalal — Mon, 25 Sep 2023 07:29:17 +0000

What is Service?
Service is a kubernetes resource which allows to direct network traffic to pods. Service can also load balance traffic across multiple pods.

There are three types of Services:
CluseterIp : Default
NodePort
LoadBalancer

Why do we need it?
Since pods are ephemeral, it may be created and removed by Deployments, to preserve connection to the nodes, we can use services. Also, NodePort service helps to route traffic from external client through a port in the node.

How it works?
ClusterIp creates a cluster specific service, pods can use the service endpoint to send data to other pods. ClusterIp selects the target pods using the Labels specified in selector configuration. All pods matching the labels in selector will be managed by a Service.

Nodeport exposes the service via an external port in all Nodes.

Load Balancer works in cloud services it creates an external ip using the cloud load balancing capabilities in addition to the service functionality.

Commands

kubectl create svc clusterip svc-name port:targetPort
kubectl create svc nodeport svc-name port:nodeport

Assignment#2 – Day 2

Yashin Jalal — Fri, 22 Sep 2023 11:50:07 +0000

What is Namespaces? Explain with Image

Namespaces is used to create multiple isolated execution environments for kubernetes resources as per different teams, departments etc. If no namespace is specified default namespace is used. Namespaces can be created and deleted using commands.

What is Pod? Explain with Image

Pod is the atomic unit of scheduling in kubernetes.
Pods are a logical unit used to group the containers.
Pods are instantiated not created. Instantiated by Kubelet

as instructed by scheduler. Pods can contain multiple containers.

What is ReplicaSets? Explain with Image

Replica set is used to run multiple replicas of a pod. 
Replicaset is similar to ReplicationController.

What is Deployment? Explain with Image

Deployment provides the capability of replca set along with a Update strategy.
Deployment can be updated using rollout command. 
Default strategy is Rolling Update, it can be changed to Recreate.

Kubernetes Training

Yashin Jalal — Thu, 21 Sep 2023 09:08:07 +0000

What is Kubernetes?

Kubernetes is tool used to orchestrate a fleet of containers across a data center. It provides the capability to manage the networking, storage, security while supporting the scalability and reliability and monitoring aspects of the containers.

Why do we need it?
To create and easily manage a large fleet of containers, ensuring reliability and availability.

How it works?
A kubernetes deployment contains multiple masters and minion nodes. The control plane is used to orchestrate the deployment and management of the lifecycle of containers in the minions.

What are the components of Master?
KubeScheduler
Kube Controller Manager
Etcd KV store
Kube API Server

What are the components of Worker?

Kubelet
Container Runtime
KubeProxy