Pushing Docker Image to Docker Hub
A custom image that only exists on your laptop is not shipped; it is a local experiment. The moment a teammate or a server needs to run it, the image has to live in a registry. Docker Hub is the one most people start with, and the push workflow is the same shape you will later use against Azure Container Registry or Amazon ECR, so it is worth doing once by hand before automating it. This post walks through that manual path with a small nginx-based image.
