Kubernetes

Introduction to Kubernetes..

Kubernetes is an open-source container management platform designed to automate the deployment, scaling, and management of containerized applications It is also known as K8. It was introduced by Google in 2014 .It was created by Joe Beda, Brendan Burns, and Craig McLuckie and other google engineer, it’s design and development of Kubernetes was influenced by Google's Borg cluster manager later it was donated to CNCF(Cloud Native Computing Foundation) to encourage collaboration, establish it as a standard, avoid vendor control, and simplify legal matters.

Importance of Kubernetes ..

Kubernetes services provide load balancing and simplify container management on multiple hosts. They make it easy for an enterprise’s apps to have greater scalability and be flexible, portable and more productive and the important work of Kubernetes is to hide the complexity of managing a fleet of containers by providing REST APIs for the required functionalities. Kubernetes is the fastest growing project in the history of open-source software, after Linux

Kubernetes Architecture and Component

Kubernetes? has client-server architecture it consists of master and worker nodes, where master node is installed on single system and worker node on many workstations

Kubernetes components

In Kubernetes components are divided into two categories that are :

1 - Control plane: The worker nodes and any pods contained within them will be under the control plane.?

Control Plane Components : These are basically the collections of components that helps in maintaining the health of a cluster.

• Kube API server : It is like command center that manages requests, maintain security and tracks the cluster status
• Kube Scheduler : It decides on which node to schedule the pod for better efficiency of the cluster
• Kube Controller Manager : It is responsible for running the controllers that handle the various aspects of the cluster’s control loop.
• etcd : It is like the memory bank for a Kubernetes cluster. It stores all the important information about the cluster's configuration, state, and data.?

2- nodes: A Kubernetes cluster needs worker nodes, which are like the computers where your containers run. Each cluster must have at least one of these worker nodes to function.

Node Components :?

These are the components where actual work is performed . Here each node can have multiple pods (containers are running inside them ).

• Container runtime : It? is needed to run the application containers running on pods inside a pod(like docker).
• Kubelet : It is responsible for managing the deployment of pods to Kubernetes nodes
• Kube-proxy : It is responsible for forwarding the request from service to the pods??

Commands for Kubectl(command line tool for Kubernetes)

View Cluster Info:

• kubectl cluster-info : display info about the Kubernetes cluster,

Cluster Management:

• kubectl get nodes : list all nodes in cluster
• kubectl describe node <node-name> : Show detailed ? information about a specific node

Pod Management:

• kubectl get pods : List all Pods in the current namespace.
• kubectl get pods -n <namespace> : List Pods in a specific namespace.
• kubectl describe pod <pod-name> : Show detailed information about a specific Pod.
• kubectl logs <pod-name> : View logs from a container in a Pod

Deployment Management:

• kubectl get deployments : List all Deployments in the current namespace.
• kubectl get deployments -n <namespace>: List Deployments in a specific namespace.
• kubectl describe deployment <deployment-name>: Show detailed information about a specific Deployment.

Service Management?

• kubectl get services : List all Services in the current namespace.
• kubectl get services -n <namespace> : List Services in a specific namespace.
• kubectl describe service <service-name> : Show detailed information about a specific Service.