What is Kubernetes?
Kubernetes is an open-source orchestration tool for deployment, scaling, and management of containers.
Developed by Google in Go language
Scaling & Load Balancing
Resource monitoring
Checks the health of nodes and containers
Networking, pods can communicate with others using ip addresss
Why Kubernetes?
open-source
Scalability
High avaliablity
How Kubernetes works?
A Kubernetes cluster is a set of Nodes and a Master
Master controls all the nodes.
apiSever{} All incoming and outgoing communication with the cluster is done through API server using JSON files
Cluster Store It maintains all information about cluster in etcd form
Controller Manager It is a script that is always running to monitor all activities in a cluster
Kube-scheduler It watches API server for all incoming tasks and schedule nodes based on affinity, constraint and resource requirement
Each node contains
a) Kubelet
b) Container Engine
c) Kube proxy
What is POD?
Pods are the smallest units in k8s
Pods can only be instantiated not created
Pod either runs or exits
Can contain multiple containers
Scaling is done at Pods level
Pods Keeps on running as long as as the containers inside the pods are running.