Understanding Dockerfiles: From Basics to Real-World Deployment
If you have been working with Docker for even a short time, you have probably heard this phrase thrown around: "just write a Dockerfile." But what does that actually mean, and how does it work under the hood? In this article, we are going to walk through Dockerfiles the same way a classroom session would. We will start from the very basics, build up through each component one at a time, and finish with a real-world deployment where you host an actual web application and a Tomcat server running Jenkins inside Docker containers. Before this, you may have created Docker images by spinning up a container, manually installing things inside it, and then running docker commit to snapshot that container into an image. That works, but it is not the right approach in practice. It is manual, error-prone, and not repeatable. The correct and professional way to create images is through a Dockerfile.
