Updates to Our Container Tagging Format

This post has been republished via RSS; it originally appeared at: Containers articles.

First published on TECHNET on Jan 26, 2019
We're introducing several minor changes to the tagging format of Windows containers. These changes will begin taking take effect next Patch Tuesday, February 12, 2019.

Build Number Tags

We’re re-introducing a build tag across all Windows base images. This will complement the existing KB-formatted tag and release channel tags. Here’s an example:
#The equivalent build number for the latest KB4480116, which went live for January Patch Tuesday:
docker pull mcr.microsoft.com/windows/servercore:10.0.17763.253
We released Windows Server 2016 container images with two tags forms. The first was the release channels, ltsc2016 and sac2016. The second was a build number. With the release of Windows Server, version 1709, we moved away from the build number to a Knowledge Base number system. That way, users could search the KB number and find the associated support article to understand what patches were in the image.

Feedback from users indicated that the KB tag alone was not clear enough in communicating which image was in fact newer or whether the container image was an exact match to their host OS version. We believe users will have an easier time distinguishing these things with the reintroduction of the build tag.

Consistent Tags Across all Microsoft Repos

To have consistency across all Microsoft container repos, going forward, all container image tags that were previously published with an underscore will now be published with a hyphen. Example:
#This is how it was before:
docker pull mcr.microsoft.com/windows/servercore:1809_KB4480116_amd64

#This is how it will be going forward:
docker pull mcr.microsoft.com/windows/servercore:1809-KB4480116-amd64
This change will affect all image tags published going forward. Old tags that used an underscore will continue to exist.

We’re also updating our arch-specific ARM images to align with the rest of the Docker community, changing from a tag of ‘arm’ for 32-bit arm to ‘arm32v7’. As an example of this change:
#This is how it was before:
docker pull mcr.microsoft.com/windows/nanoserver:1809_arm

#This is how it will be going forward:
docker pull mcr.microsoft.com/windows/nanoserver:1809-arm32v7

Container Repo Structure

In related news, Docker introduced changes to Docker Hub. Docker Hub is the home to our new repository structure.

The new structure allows us to have a repository family page—the “Windows base OS Images”—displayed above. From there, the family page links to the individual repos for all Windows container base images and points users to related repos. You can read more in a blog post from Rohit Tatachar, PM for Container Registry.


For more information, please visit our container docs at aka.ms/containers . Let us know your thoughts about the new repo structure in the comments below!

Leave a Reply

Your email address will not be published. Required fields are marked *


This site uses Akismet to reduce spam. Learn how your comment data is processed.