Let’s recognize the meaning of each command.
FROM – This command is a charity to specify the name and version of the operational system. Here we have requested Docker to install the newest version of Ubuntu. We can set the version of the operating system like this: FROM ubuntu:16.04.
RUN – This is used to give directions to our newly created operating system. Here, I am requesting my operating system to apprise itself and then install the python-pip, python-dev, and build-essential packages
COPY – We copy all the documentation from the first limitation (.) to the terminus parameter (/app).
WORKDIR – It is used to set the employed directory for our app. All the orders after this command will perform within this calendar only.
ENTRYPOINT – This command is a charity to configure the container to run as an executable. Note: If you set numerous commands here, only the last training will be performed.