What is the purpose of a Dockerfile?

The purpose of a Dockerfile is to define how to build a Docker image. A Dockerfile is essentially a text file that contains all the commands, instructions, and configuration settings needed to assemble a Docker image. When you run the docker build command with a Dockerfile, Docker processes this file and creates an image based on the specified instructions.

This process allows developers to automate the image creation and ensure that images are built consistently every time, regardless of the environment. The Dockerfile can include a variety of commands such as setting the base image, installing software packages, copying files, and defining environment variables. By using a Dockerfile, you not only streamline the image creation process but also provide a transparent way to version control and replicate the environment setup.

The other options represent different functionalities that are not related to the purpose of the Dockerfile. Storing running container configurations, managing network settings, and monitoring volume usage are handled through other Docker commands and configurations rather than through a Dockerfile.