Kubernetes Introduction-Nagendra

Features of containers

 collection of containers

Replication Controller

Storage Management

Resource Monitoring

Health Checking

Networking

Helm Charts

POD Distrubution

Cluster Federation

How kubernates works?

Kubernetes supports several base container engines, and Docker is just one of them. The two technologies work great together, since Docker containers are an efficient way to distribute packaged applications, and Kubernetes is designed to coordinate and schedule those applications.

What are the components in master?

API Server

Scheduler

Controller Manager

etcd

Kubelet

Kube-proxy

What are the component of workers?

A Kubernetes cluster consists of a set of worker machines, called nodes, that run containerized applications. Every cluster has at least one worker node

  • kubelet
  • kube-proxy
  • and PODS. Each POD can have multiple containers as required

Components of Workstation

  • kubectl
  • creation of json/yaml file

POD?

Pods are the smallest, most basic deployable objects in Kubernetes. A Pod represents a single instance of a running process in your cluster.

Pods contain one or more containers, such as Docker containers. When a Pod runs multiple containers, the containers are managed as a single entity and share the Pod’s resources. Generally, running multiple containers in a single Pod is an advanced use case.

  • Pods represent the processes running on a cluster. By limiting pods to a single process, Kubernetes can report on the health of each process running in the cluster
  • a unique IP address (which allows them to communicate with each other)
  • persistent storage volumes
  • configuration information that determine how a container should run
  • Pods are created by workload resources called controllers, which manage rollout, replication, and health of pods in the cluster. For example, if a node in the cluster fails, a controller detects that the pods on that node are unresponsive and creates replacement pod(s) on other nodes
  • Although most pods contain a single container, many will have a few containers that work closely together to execute a desired function.
  • Pods are almost always created by controllers which then can automatically manage the pod lifecycle, including replacing failed pods, replicating pods when necessary, and evicting the pod from cluster nodes when they are complete or no longer needed