DevOps Traning/Interview questions

  TABLE OF CONTENTS DOCKER FILE PROJECT: Build a container for a Flask Calculator App Docker  plays a major role in building the application by improving its efficiency. It containerizes the application by creating an image which is portable i.e. can be run anywhere in any specification of the server. Here comes the base of Docker which is called a  Docker file . Let's learn what is it and how it sets a standard from application to apply through its configuration. DOCKER FILE A docker file is a text file with a set of information that Docker reads to build an image about it. The file contains similar commands as we give CLI commands to build an image manually but here we combine all the steps to execute at a time. The format for writing the docker file is:- Environment variables are supported by the following list of instructions in the Dockerfile : ADD  - It gives instructions to copy new files, directories, or remote file URLs and then adds them to the filesystem of the image. CO