Docker: how to publish images to a registry and version them?

Publishing images to registries and proper versioning form the basis of a modern CI/CD process and secure application delivery to end servers. The first step in mastering this process is carefully reading the documentation of the registry you are using, whether it is Docker Hub, GitHub Packages, or a private corporate registry.

To successfully publish, you need to log in to the system using the docker login command by entering your credentials or personal access token. Authorization errors often occur due to typos in usernames or incorrect token permissions, so terminal messages should be read fully and without haste.

The next step is properly tagging the locally built image using the docker tag command, specifying your repository name and a specific version. It is strictly discouraged to constantly use the latest tag for a production environment, as this makes rolling back to a previous working version impossible in the event of an incident.

Apply semantic versioning by assigning tags like v1.2.0 to images, which allows you to clearly track changes and understand the scope of updates. After tagging, the image is sent to the remote storage using the docker push command, which transfers all layers over the network.

If network or access denied errors occur during publication, the system message almost always contains a hint about which specific part of the authentication or repository name was specified incorrectly. Careful analysis of the full error text allows you to resolve deployment issues in a matter of minutes.