As we have seen, we can execute individual commands from the Shell. Docker provides a decent method to invoke several commands and instructs the new container to perform a specific job.
Dockerfiles is a script based on different Docker commands. Each command contains an instruction, and it configures the new machine step by step. It can contain all the information from pulling a repository to starting any server.
They have a clean and simple syntax that makes a file more readable and clear. It is designed to be self-explanatory and allows commenting like other programming languages.
Here is an example of a file syntax:
# Comments command argument argument … # To echo Hello World RUN echo "Hello World"
Let's create a basic Dockerfile and use the same example of Hello World as follows:
Add the following content to Dockerfile:
# Dockerfile FROM ubuntu RUN echo "Hello World"
Build the Docker container with the following command:
$ sudo docker build -t local/test_dockerOur new container...