Chapter 5. Building and Sharing Docker Images

Docker images are an essential part of containerized applications, providing a lightweight, portable, and consistent runtime environment. In previous chapters, we covered how to run containers using pre-built images from Docker Hub, but what if you need a customized setup for your application? That’s where building and managing your own Docker images becomes important.

In this chapter, we’ll explore how to create images using Dockerfiles, optimize builds with a .dockerignore file, and share images across teams and repositories. Understanding these concepts is crucial for maintaining efficiency, consistency, and security in your development and deployment workflow.

So far, we've worked with Docker Official Images—trusted, well-maintained base images provided by Docker and its community. These images, such as those used in previous chapters, offered a ready-to-use environment for running applications. However, we haven’t yet explored how to create custom images tailored to specific project requirements or how to share them through a repository. This chapter bridges that gap, ensuring you have the necessary skills to build and distribute your own Docker images effectively.

Docker Official Images vs. Custom Images

Before building your own Docker images, it’s important to understand the different types of images available. In Docker, an image is a packaged environme