kubelet :An agent that runs on each node in the cluster. It makes sure that containers are running in a Pod. kube-proxy :kube-proxy maintains network rules on nodes. Manage communication within the cluster and outside the cluster. Also assign ip address for pods Container runtime: For managing and run the containers.

API server : It is the front end for the Kubernetes control plane, exposes the Kubernetes API. All other components interact with api server. SchedulerThis is one of the key components of Kubernetes master. It is a service in master responsible for distributing the workload. Controller ManagerControls the Kubernetes cluster. It includes the Endpoints Controller, Replication Controller, and Namespace Controller etc etcd : Consistent and highly-available key value store used as Kubernetes’ backing store for all cluster data

Container orchestration Manages state of container Auto healing function Auto Scaling Load balancing Easy deployment Implement the changes easily Automated rollouts and rollbacks

Azure File Storage plugin BeeGFS Volume Plugin Blockbridge plugin Contiv Volume Plugin Convoy plugin DigitalOcean Block Storage plugin DRBD plugin Flocker plugin Fuxi Volume Plugin gce-docker plugin GlusterFS plugin Horcrux Volume Plugin HPE 3Par Volume Plugin Infinit volume plugin IPFS Volume Plugin Keywhiz plugin Local Persist Plugin NetApp Plugin (nDVP) Netshare plugin Nimble Storage Volume Plugin OpenStorage Plugin Portworx Volume Plugin Quobyte Volume Plugin REX-Ray plugin Virtuozzo Storage and Ploop plugin VMware vSphere Storage Plugin

FROM : Set base image MAINTAINER : Author of docker file RUN : Run the commands in new layer VAR : Used to set variable, we can re-use these variables later EXPOSE : specify port of the container COPY : Copy files to the container ADD : copy files into container and extract it USER : Set the runtime user ENV : set environment variable CMD : to set PID1 ENTRY POINT : to set PID1 WORK DIR : set

Docker image is a collection of file system Can create multiple container from same image File systems are layered over each other Layer 0 is the base image All layers in a docker image is read only. Image layering is by Union Mounts

1993 docker run -itd –name=sjt ubuntu1995 docker ps |grep sjt1998 docker attach sjt apt-get update apt-get install git apt-get install ntp apt-get install apache2 1999 docker commit -a”Sujith Sunny” -m”ub-up-git-ap2″ sjt ub-up-git-ap22000 docker images

Storage drivers are used to store image layers, and to store data in the writable layer of a container. Types are overlay,overlay2,fuse-overlayfs,btrfs,zfs,vfs,aufs and devicemapper. overlay2 is the default storage driver.

docker wait command is used to block the container until the container exit. once the container is stoped, it returns the exit code (0)

docker update command is used to update the default configuration of a specific container.for example, limiting resources like memory, cpu etc

Docker pause is used to pause all the processes in the container, but the memory will be still used. Docker unpause will resume the processes.

Docker kill will stop all the processes in a container forcefully but docker stop will stop the processes gently.

The docker container is an independent light weight environment for running an application, docker image is the package used to create, run and deploy application in containers.