Microsoft has updated its Microsoft Container Registry to make it easier for developers to create and share container images using Docker Hub.
The developer-focused improvements were announced by Rohit Tatachar, program manager for the Microsoft Container Registry, in a recent post on the Microsoft Open Source Blog.
“In partnership with Docker, Microsoft has sought to improve the developer experience and servicing of container images while maintaining the current discovery and acquisition process via Docker Hub,” wrote Tatachar. “The Microsoft Container Registry does not have its own catalog UI experience and Docker Hub continues to be the official source for our customers to discover official Microsoft-published container images.”
Container registries and their related catalogs allow developers to reuse trusted and secure container images that were created by others so they can work on their own projects without having to start from scratch, which is a huge benefit.
Microsoft has been working since May of 2018 to begin migrating a small selection of container images from microsoft/* to mcr.microsoft.com/* and has now moved most of the images over while still maintaining the discovery experience on Docker Hub, wrote Tatachar. “The transition is still in progress and we hope to have 100 percent of the repos moved to MCR within the next few months.”
At the same time, Microsoft has been moving official images from the “community” listing to the “Verified Publisher” category on Docker Hub, he explained. “With this update, Microsoft images can be searched by selecting the ‘Verified Publisher’ checkbox in the new Docker Hub user experience. The images themselves have not changed with this transition—there is no change to the pull experience of the image, only to the discovery experience.”
To ensure that all existing and new customers are supported, all the currently supported image tags pulled from Docker Hub will continue to work, wrote Tatachar. “Whether you’ve deployed the image as docker pull microsoft/* or referenced the image in a Dockerfile FROM statement, if the tag was pulled from Docker Hub, it will continue to work. This is true for the latest tag as well.”
Any supported tags posted to Docker Hub will also be available on mcr.microsoft.com to provide a clean migration, but new tags are available only on MCR and not on Docker Hub, he added.
As the container registry expands, Microsoft plans to continue to syndicate with other public container catalogs along with Docker Hub, including Red Hat Container Catalog and Azure Marketplace to provide even more container images for reuse, he wrote. “We want to maintain the best developer experience via these ‘centers of expertise’ for Microsoft customers.”
As part of the process, Microsoft is also working to update associated readme files with common headings, including Featured tags, Featured Repo and others, to make the catalogs easier to use. “By automating the MCR content (readme) flow creation process to the syndicated catalogs, MCR repositories will now consistently display tags in a tabular structure that contains all the most relevant information, including the Docker file, created date, etc.,” wrote Tatachar.