As you may recall from Chapter 5, Finding Images, one of the coolest Docker Hub features are the automated builds. An automated build is triggered by webhooks when changes are made to a source code of the image (that is, to Dockerfile). Webhooks let you execute different actions after pushing an image to a repository. Automated Builds repository automate the building and updating of images from the most popular git repositories, namely GitHuborBitbucket, directly on Docker Hub. Automated builds repository can be created either for private or public repositories. It works by adding a commit hook to your selected GitHub or Bitbucket repository; thus, triggering a build and update when you push a commit. Automated Builds repository have several advantages, images built this way are built exactly as specified, the Dockerfile is available to anyone with access to your Docker Hub repository, and your Docker repository is automatically always up-to-date with source...