Kubernates works with many components It has cluster Master Nodes Kubernates master acts as incharge. Nodes AKA minions acts as “Doing the work” Master has api server —which recives the request Controller —whcih watches the changes and maintain the desired state etcd — which acts as a storage device(store values in key-value pair Scheduler–which assign works to nodes Node –It can contain the single pod, or multiple pods.. Kubelet –registers nodes with cluster, instantiates the pod Container –pulling the docker

Demystifying Kubernetes Kubernetes (aka k8s) helps solves multi fold problems we can face while putting an application that’s required to scale while on production. It is mainly used as an orchestrator of containers in a cluster environment (i.e. multi-node environment for distributed applications). The following are the problems and the role it plays in solving :- Problems Kubernetes features Managing containers on different nodes Workload placement in multi-node clusterAim – Manage services/application or their replicas spread acrossdifferent nodes effectively –

Kubernetes is an open source tool to manage containerized applications, it was initially developed by Google. Kubernetes solves the problem of managing containers to automatically scale-up/ scale-down when the nodes having the container fails, so it will deliver the required performance with the desired number of services are always running. Kubernetes also provides the load balancing technique in simple/ round-robin fashion though the same container is running in same node. Kubernetes guarantee the number of pods (containers/services) always running at

A Kubernetes cluster consists of a set of worker machines, called nodes, that run containerized applications. Every cluster has at least one worker node. The worker node(s) host the Pods that are the components of the application workload. The control plane manages the worker nodes and the Pods in the cluster. In production environments, the control plane usually runs across multiple computers and a cluster usually runs multiple nodes, providing fault-tolerance and high availability. This document outlines the various components you need to have for

Kubernetes, also known as K8s, is an open-source system for automating deployment, scaling, and management of containerized applications. Open source container orchestration tool It can manage in physical , hybrid and cloud environment No downtime High performance and scalability

Kuberates is an orchestration, It routes all the workload in the described manner it manages the infrastructure. it maintains the desired state it autoscales, self healing, load balances, and rollbackes in cases of failure its quicker and faster it’ll do lot of job under the hood

Kubernetes is an open-source platform that enables automated deployment, scaling, and management of containers and containerized applications. It can be used on-premises or in the cloud. Common use cases of k8s include hybrid and multi clouds, creation of vendor-agnostic serverless platforms, or deployment of self-healing and scaling services. While k8s is not the only orchestration platform available, it is the most supported. Docker Swarm and OpenShift are both alternative options. 10 Kubernetes Features to Know Once you’ve got a grasp

Multiple services can be defined and run together making it easier to run. Can make all the services up and down at a time. Can make even a single service up/down Multiple isolated environments on a single host Preserve volume data when containers are created Only recreate containers that have changed Variables and moving a composition between environments

1.Compose is a tool for defining and running multi-container Docker applications 2. A YAML file is used to configure all the application services 3. With a single command the services can be created and started using the defined configurations 4. Compose has command to start , stop and rebuild services. 5. docker-compose can be used to view the status of the running services. 6. It can stream the log output of running services. 7.docker-compose only recreates containers that have changed.

1. Main feature – Put configuration of all App Layers in 1 place Specify logically as “Services” all the docker containers needed for different parts of your overall application.For ex: – WebApp, Business service, DB Layer and even the networking needed along with necessary information like ports. Also can specify which service depends on what. 2. Start your App services in 1 shot – Docker-compose up 3.Key ways to stop app in 1 shot – Docker-compose stop v/s Docker-compose down

Multiple isolated environments on a single host Preserve volume data when containers are created Only recreate containers that have changed Variables and moving a composition between environments Orchestrate multiple containers that work together Single host deployment  Quick and easy configuration – Due to YAML scripts. High productivity – Docker Compose reduces the time it takes to perform tasks.

Multiple isolated environments on a single hostCompose uses a project name to isolate environments from each other. You can make use of this project name in several different contexts: on a dev host, to create multiple copies of a single environment, such as when you want to run a stable copy for each feature branch of a projecton a CI server, to keep builds from interfering with each other, you can set the project name to a unique build numberon

Helps in building the common utility (yaml files) to describe the servicess and use it in a single command YAML files are readable Helps to perform operations on all the containers in a single command Single host deployment Quick and easy configurations Highly productive – save time

Runs multiple containers from a single file and allows common access a) docker-compose run: run file b) docker-compose create: create services c) docker-compose stop: stop services d) docker-compose up: create and run e) docker-compose down: stop f) docker-compose rm g) docker-compose ps h) docker-compose push i) docker-compose pull

docker-compose pull Performs the docker pull for all the services with respective images mentioned docker-compose create Executes the docker create for all the service (create container for all the service) docker-compose run Executes the docker create for all the service (run container for all the services) docker-compose up It combines build, create, run commands in one shot docker-compose stop Stops all the containers of services docker-compose rm Removes the stopped containers docker-compose down It combines stop and rm, executes for

Docker compose is used for running multiple container as 1 service Each service is isolated from one another No dependency to start each service independently one yaml file contains all and can be run in 1 shot Docker manages single container , docker-compose manages multiple applications It is a powerful tool , to set up and deploy application Start all services: Docker Compose up. Stop all services: Docker Compose down. Run Docker Compose file: Docker-compose up -d. List the entire

A tmpfs mount is temporary, and only persisted in the host memory. When the container stops, the tmpfs mount is removed, and files written there won’t be persisted. This is useful to temporarily store sensitive files that you don’t want to persist in either the host or the container writable layer

What is tmpfs ? Assign memory from host’s RAM to the container which is normally outside of the write-able memory that the container gets when its created and run. This memory will eventually get removed once container lifecyle ends How to create tmpfs ? Command to mount on /app in container with permission of 1770 As we can see the filesystem for /app is created. Also notice this path /app doesn’t exist usually in a default ubuntu container

This is in-memory file system Tt will not be seen anywhere in the host/container filesystem This volume cannot be shared among containers Once container is stopped/restarted stored info will be lost It is recommended to use for high speed temporary storage

5 Differences between CMD and ENTRYPOINT with example CMD Entrypoint the executable command will be replaced by the command 1. The executable command can’t be changedgiven while running the container We can’t pass the arguments for the CMD command 2. The commands passed while running the container will be appended to the RUN command Multiple times can be added in the dockerfile 3. same as CMDbut the last line will override the previous Choose CMD if you need to provide