Why is it important to document ports with the EXPOSE instruction?

Documenting ports with the EXPOSE instruction is crucial for informing users about network access options. When you use the EXPOSE instruction in a Dockerfile, you are indicating which ports the container will listen on when it is running. This is especially important for anyone who might be using the container, as it clearly communicates which ports are designed for external communication and how they can interact with the application running inside the container.

This transparency helps users understand how to connect to the application, whether they need to map those ports when running the container, or how to configure their own network settings to allow access. By providing this information upfront, you facilitate better usability and interoperability with other systems or services that may need to connect with your containerized applications. This clear documentation leads to fewer misunderstandings and issues when deploying or integrating the containerized application in a networked environment.