Skopeo is planned to be used to copy already signed images between two or more private registries.
In my situation, the images are already signed in a private source registry. This signature is also shown as existing within the source registry.
If this signed image is copied directly between the two registries - there is a graphical front end in the registry product for this - the image includes the signature appearing on the target registry.
However, this solution cannot be used due to other disadvantages. Thats the reason trying skopeo for a potential solution.
A $skopeo copy docker://192.168.x.y/images/test:0.1 dir:test_0.1 copies the image including the signature into the test_0.1 directory - into signature-1.
However, a copy directly between two registries does not work:
$skopeo copy docker://192.168.x.y/images/test:0.1 docker://192.168.y.z/images/test:0.1
Getting image source signatures
Checking if image destination supports signatures
Copying blob 96526aa774ef skipped: already exists
Copying blob 5b088f1e648c skipped: already exists
Copying config 33b8df73a9 done
Writing manifest to image destination
Storing signatures
FATA[0000] writing signatures: reading manifest sha256-blablabla.sig in 192.168.y.z/images/test: unknown: artifact images/test:sha256-blablabla.sig not found

Also, there is no positiv result trying to copy the content from inside the local directory. The same message is the result.

My question is: might it be that Skopeo cannot be used to copy images between two or more registries that are already signed in the source registry? There are no plans to re-sign the image with the private key in between again. This signature should be adopted 1:1 into the target registry - just as the registry product itself can do, although there are other reasons against using this solution.

May I ask for assistance or is this some kind of issue or enhancement?