Intro to Dockerfile
A Dockerfile is a text document that contains all the commands a user could call on the command line to assemble an image.
In otherwords, it will have commands that you want to run to build your docker image.
Example file -
# This image is based on python:3.9 docker image
from python:3.9
# install pandas in the base image.
RUN pip install pandas
# Make the entrypoint for this image as bash.
# Same as docker run -it -entrypoint=bash python:3.9
# This will run docker image and instead of python prompt you will get bash.
ENTRYPOINT [ "bash" ]