Docker.

When you build an application did it ever happen that it worked perfectly on your local system and didn't show up rightly on other's machine? It is because the dependencies vary and Docker comes as a Saviour. Deploying applications on containers makes it easier to test, scale and identify issues. Docker containers are highly portable.

What is Docker? Docker is a open platform for developing, shipping, and running applications. It works based on the containers that package the application source code with OS libraries and dependencies along with executable components that are needed to run application in any environment.

Structure of Docker

Docker engine functions works on top of Host Operating System using which containers are formed. These contain the dependencies and code packaged within. Docker engine allows multiple containers to run parallelly and they are isolated.

Working of Docker

A Developer writes code that defines applications ,dependencies in a docker file. This produces docker image that consists of all the dependencies and requirements for that application. The below docker containers are the run time instances of docker images.

These docker images are pushed to the docker hub from which any one can pull the image and prepare there own containers. In software development cycle any team such as Quality Assurance or production teams pull images and work on those applications.

Where docker is used? Docker enables to make code available throughout different stages in software development life cycle. It provides consistent computing environment for running code at different stages such as development, testing, and production. This saves us from environment set-up configuration settings. Docker file is pushed to code repository so that every team has access to use it.