Docker

Docker Images Are Portable

A Docker registry is a platform used to manage and distribute Docker images. Users interact with them by pushing and pulling Docker images.

Comparing Docker Registries with Git Platforms

Docker registries are very similar to Git platforms. It helps to use it as a reference to help build familiarity with the terminology used with Docker.

Docker Registry - Git Platform

Docker Registries are equivalent to Git platforms. For example, DockerHub or AWS ECR is equivalent to GitHub or GitLab.

Docker Repository - Git Repository

Docker Repositories are equivalent to Git repositories.

Docker Image - Version Controlled Content

Docker images are equivalent to version controlled content. The main difference is that we have generally 1 Docker image per version, version controlled content in Git may have many files.

Image Tag - Git Commit

An image tag is equivalent to a git commit. However, each image has its own tag and each tag is generally its own release. Whereas with git, a release may have one to many commits included in it.

Referencing a Docker Image

Docker images can be identified by the following format: <registry_path>/<repository_name>:<image_tag>

Commands

The main way to interact with a container registry is to push to and pull from the registry.

• docker push <IMAGE_TAG> - pushes the Docker image to the container registry

• docker pull <REMOTE_DOCKER_IMAGE_PATH> - pulls the Docker image from a remote registry to become available in the current environment