Limited Time Offer! For Less Than the Cost of a Starbucks Coffee, Access All DevOpsSchool Videos on YouTube Unlimitedly. Master DevOps, SRE, DevSecOps Skills! Enroll Now Pod is the atomic unit of scheduler in K8s. Pods contains one or more containers, at least one. K8s(kubelet) will instantiate pods. Pod is running as long the container inside is running. Life cycle of pod – Pending, Running, Succeded/ Failed Pods will communicate with each other through a pod network – inter pod

Limited Time Offer! For Less Than the Cost of a Starbucks Coffee, Access All DevOpsSchool Videos on YouTube Unlimitedly. Master DevOps, SRE, DevSecOps Skills! Enroll Now kubelet – This is the main K8s agent. It inistantiates the pods in the node. It helps to register nodes with cluster. Its always watch the api server. kube-proxy – Its support for K8s networking. It provide ip address for the pods. Each pods inside a node will have same ip address. kube-proxy rules

Limited Time Offer! For Less Than the Cost of a Starbucks Coffee, Access All DevOpsSchool Videos on YouTube Unlimitedly. Master DevOps, SRE, DevSecOps Skills! Enroll Now API server – It contains all the APIs provided by K8s. It acts as the front-end, we access via REST. It is like ears in human body, it receive the things. Cluster store – All the requests / data stored in cluster store. etcd is the storage unit use by k8s. It is like

Limited Time Offer! For Less Than the Cost of a Starbucks Coffee, Access All DevOpsSchool Videos on YouTube Unlimitedly. Master DevOps, SRE, DevSecOps Skills! Enroll Now K8s can manage the scalability challenge bring by containers. K8s runs many containers as a cluster K8s is a container orchestrator K8s provide the desired state – we desired to have 1000 containers K8s is self maintaining – self healing Auto rollback Auto scaling K8s managing load balancing K8s absorb changes K8s provide very

Limited Time Offer! For Less Than the Cost of a Starbucks Coffee, Access All DevOpsSchool Videos on YouTube Unlimitedly. Master DevOps, SRE, DevSecOps Skills! Enroll Now Union mount is a type of a filesystem that can create an illusion of merging contents of several directories into one without modifying its original (physical) sources. Union mount or union filesystem is not the filesystem type, but rather a concept with many implementations. UnionFS, aufs, OverlayFS, ZFS, and Btrfs are different implementations of

Limited Time Offer! For Less Than the Cost of a Starbucks Coffee, Access All DevOpsSchool Videos on YouTube Unlimitedly. Master DevOps, SRE, DevSecOps Skills! Enroll Now A Docker image is built up from a series of layers. Each layer represents an instruction in the image’s Dockerfile. All layers except the last one is read-only. To identify each layer separately, Layers are now identified by a digest, which takes the form algorithm:hex; for example: sha256:fc92eec5cac70b0c324cec2933cd7db1c0eae7c9e2649e42d02e77eb6da0d15f The hex element is calculated by

Limited Time Offer! For Less Than the Cost of a Starbucks Coffee, Access All DevOpsSchool Videos on YouTube Unlimitedly. Master DevOps, SRE, DevSecOps Skills! Enroll Now overlay2 / overlay – default storage driver for all linux flavors aufs – AUFS is a union filesystem, which means it presents multiple directories called branches, in AUFS as a single directory on a single Linux host. These directories are known as layers in Docker. devicemapper – It is a block storage driver that

Limited Time Offer! For Less Than the Cost of a Starbucks Coffee, Access All DevOpsSchool Videos on YouTube Unlimitedly. Master DevOps, SRE, DevSecOps Skills! Enroll Now FROM – Mention a docker image name. Ex: FROM ubuntu MAINTAINER – Mention about the author who create the docker file. Ex: MAINTAINER BittoKC RUN – To execute any command on the container. Ex: RUN touch /tmp/file1.txt ARG – To set an environment variable. Ex: ARG USER1 gehc_security EXPOSE – To specify about the

Limited Time Offer! For Less Than the Cost of a Starbucks Coffee, Access All DevOpsSchool Videos on YouTube Unlimitedly. Master DevOps, SRE, DevSecOps Skills! Enroll Now Collection of file systems, ROOTFS, APPFS, USERFS. One copy of docker image can attach to many containers. From one image multiple containers can be created File system layered over each other. Higher layer wins. Each layer is each File system Layer 0 should be base image or Root FS Once image is attached to

Limited Time Offer! For Less Than the Cost of a Starbucks Coffee, Access All DevOpsSchool Videos on YouTube Unlimitedly. Master DevOps, SRE, DevSecOps Skills! Enroll Now The wait command will wait until a container stop, then print their exit codes.How to check:Start a containerdocker run –name bitto httpdRun docker waitdocker wait bittoKill the container from another terminal and check the return value in actual terminaldocker kill bitto

Limited Time Offer! For Less Than the Cost of a Starbucks Coffee, Access All DevOpsSchool Videos on YouTube Unlimitedly. Master DevOps, SRE, DevSecOps Skills! Enroll Now “docker update” command dynamically updates container configuration.Using this command we can restrict the usage of too many resources by a container.Example : docker update –kernel-memory 50M ad5f8182d65e –> Update kernel memory while the container is running

Limited Time Offer! For Less Than the Cost of a Starbucks Coffee, Access All DevOpsSchool Videos on YouTube Unlimitedly. Master DevOps, SRE, DevSecOps Skills! Enroll Now We can successfully execute the command docket pause only if the docker container is in running state. We can successfully execute the command docket unpause only if the docker container is in paused state. I think internally its deallocating (during pause) and reallocating (during pause) the resources.

Limited Time Offer! For Less Than the Cost of a Starbucks Coffee, Access All DevOpsSchool Videos on YouTube Unlimitedly. Master DevOps, SRE, DevSecOps Skills! Enroll Now docker stop It is stopping a running docker container. It is a graceful termination of docker container with exit code – Exited (0) docker kill It is killing a running docker container. It is a forceful termination of docker container with exit code – Exited (137)

Limited Time Offer! For Less Than the Cost of a Starbucks Coffee, Access All DevOpsSchool Videos on YouTube Unlimitedly. Master DevOps, SRE, DevSecOps Skills! Enroll Now Docker container image is a light weight and independent application run time environment.It is a collection of users attached with at least 1 root file system, 1 pid and 1 network.