Defined kubernetes in Rajasekhar words
What is Kubernetes ?
-Kubernetes is a container orchestration tool which was intially developed by Google and then dontated to CNCF.
-Kubernetes is also an orchestration tool for microservice apps
-With kubernetes we can over come scalability challenges that comes with containers.
-With kubernetes we can acheive Auto scaling, load balacning, self-healing.
-Few benefits of kubernetes on a high level note are.. It enhances productivity, centralized control over cluster, security, scalability, portability.
Why Kubernetes ?
-Kubernetes can be used to overcome the challenges that comes with containers.
-To archieve load balancing and scalability over containers.
-For high availability
How Kubernetes works ?
-Kubernetes works in a master-node(s)[worker] model, it’s a cluster
-We’ll have a master and multiple worker nodes, for the best practices we have multiple masters as well(probably 3 masters in a cluster)
-Master has mainly 4 components i.e. apiserver, cluster-store, scheduler, controller-manager
-Worker node mainly have 3 components, kubelet, container engine, kube-proxy
-Kube-proxy is a networking service in Kubernetes.
-Kube-proxy between node-network & pod-network.
-Every information(any communication) should be passed through apiserver (Internally/Externally) of the cluster
What is POD ?
-POD is a compute unit
-POD’s can be instaniate not created
-POD can have one or more containers
-One or multiple containers goes down the POD will be instantiated.
-Lifecycle of pod is pending running, successfull/failed
-PODs are ephemeral i.e. pod can be replaced not with the same.