Create a namespace with your name and assigne one dummy resourcesquota to it and deploy a app of mysql in your namespace. created the name spacekubectl create ns ajins created a ode in that name spacekubectl create deployment ajidep –image=mysql -n ajins applied the resourseskubectl apply -f rs.yaml –namespace=ajins kubectl get resourcequota mem-cpu-demo –namespace=ajinsNAME AGE REQUEST LIMITmem-cpu-demo 22s requests.cpu: 0/1, requests.memory: 0/1Gi limits.cpu: 0/2, limits.memory: 0/2Gi

A pod is a unit which can have one or more unit which can be runIt will have a unique IPIt will have config info for a containerThe pod initialize the containerThe will in running state when the container is started.The pod ceases to exist when the container is terminatedPod can not be restarted, we can start a similar podIt is like a logical host for the containerEvery pod has the status likePending : created but the container is not

kubelet : This component ensure that containers are running in the podkube-proxy : This the network proxy that is running on each nodeDocker or any container runtime : this will run the docker/ any other container

API Server : The apis to communicate with outside world and between components. It provides api for all the operationsetcd : it is a data store used by Kubernetes to store the config data. All the communication to etcd is via api server Controller Manager: It runs in a loop to check teh state of each node Scheduler: this is the service which manages teh workload of nodes

memory – tempfs –> exists as long as the docker is livemount – to mount to a host locationvolume – use the docker /var/lib/docker/volumes

FROM ubuntuMAINTAINER Rajesh Kumar << rajesh@scmgalaxy.com>>ENV DEBIAN_FRONTEND=noninteractiveRUN apt-get updateRUN apt-get updateRUN apt-get -y install tzdataRUN apt-get update && apt-get install git -y && apt-get install -yq apache2ENTRYPOINT [“/bin/echo”, “Hello” && “/bin/echo”, “Second entrypoint”] FROM ubuntuMAINTAINER Rajesh Kumar << rajesh@scmgalaxy.com>>ENV DEBIAN_FRONTEND=noninteractiveRUN apt-get updateRUN apt-get -y install tzdataRUN apt-get update && apt-get install git -y && apt-get install -yq apache2CMD echo “Hello world” /usr/sbin/apache2ctl -D FOREGROUND

FROM – to specify the parent image. Eg ubuntu from which you create an imageMAINTAINER – to set the author/creater of the imageRUN – to run a command like shell script in linux or execute a programARG – should be used along with FROM to speficy any arguments lie versionEXPOSE – To inform the docker that the container listern on the given portCOPY – to copy files or dir to the container destination pathADD – to copy files or dir

Docker image is a file to run code in container. It contains all the file/software that you needed to run your application. It has multiple layers. Each layer is originated from the prev. layer. The top layer is editable. We can create images out of existing images. We can add the lib or changes that we need and commit it.

Steps docker run –name aji_4 -itd centosattach to ityum install gityum install httpd yum install epel-releaseyum install -y ntp

Docker uses the storage driver to store image layers

Steps used to create the docker image create a docker containerattach to itapt updateapt install gitapt install ntpapt install apache2docker commit -a”Aji Raphel” -m”created a docker image with ubuntu+git+ntp+apache2″ b3bab63b207d aji_ubuntu

Created 67191c577f06 maven 543a405cd47f python 7467476804b7 tomcat 9e7a8f09a553 groovy 1b4fdcf080a9 sonarqube

The docker wait command blocks the container till it is stopped Eg. docker wait 829414517f17

Docker update command is used to update the configuration of the already created docker image. We can update the CPU, memory etc. by using the update command. Eg : docker update –memory 8M 829414517f17 Result : 829414517f17 aji_0 0.00% 7.445MiB / 8MiB 93.07% 1.51kB / 0B 0B / 0B 82

Pause will set the container state to Paused and all the processes in the container will be suspended. Unpause will unsuspend the process and removes the unpaused state

Docker stop will gracefully stop the container. It stops the processes before killing the container Docker kill will kill the container immediately

It is a container which provide you an environment to run your application. You can create a container with all the basic setup needed for your application to run and run your application