How to setup Docker mirror proxy Repository in Nexus Repository ManagerOSS 3.19.1-01?
In Nexus, go to the Admin Backend.

Create a blob store if you haven't already. Guidance can be found here: https://help.sonatype.com/repomanager3/configuration/repository-management#RepositoryManagement-BlobStores

Once you have a blob store, continue like so:

Choose "Repositories", hit "Create Repository". Choose "docker (proxy)" as the recipe.

Give it any name (for example "docker-hub").

Under "Remote storage" enter https://registry-1.docker.io.

As "Docker Index" select Use Docker Hub.

Select a blob store for it (which you have created above).

Hit "Create repository". No more configuration is needed for the proxy repo.

Next up: A group repository, from which you will pull:

Go back to "Repositories" and hit "Create repository" again. This time select "docker (group)".

Call it anything you like (for example "docker-group").

For "HTTPS" enter any port you like. (we have 10500)

For blob store select any blob store (for example the one you have created above).

Under "Group" select for "member repositories" the repository you have created above.

You can also add a "docker (hosted)" repository as well if you have one set up. (I will explain later)

Hit "Create repository".

Now open your Docker cli and do a pull of some Docker Hub image but don't pull it from Docker Hub, pull it through the HTTPs endpoint of your docker (group) repo that you have created above like so:

$ docker pull my.repository.com:10500/phpmyadmin/phpmyadmin


This will create a pull request to your Nexus OSS, which will proxy the request to Docker Hub. The image from Docker Hub will be cached in your Nexus and will be delivered to you.

After pulling browse your docker (proxy) repo that you have created above and check the images inside. You will find a phpmyadmin/phpmyadmin inside (or any other image you have checked out) with a current timestamp.

Hope that helps!