harbor: Broken replication of the "///" docker images

Hello Harbor team,

Starting from the Harbor v2.1.0 the replication of the docker images that have name <registry URL>/<namespace>/<project>/<image>:tag is broken. Such images can’t be replicated. It also seems like in such cases replication process drains all the available CPU and RAM resources leading to DoS.

Harbor v2.0.3 doesn’t have this issue.

Images that have <registry URL>/<namespace>/<project>:tag name replicate without any issues.

It is also possible to push <registry URL>/<namespace>/<project>/<image>:tag image directly to Harbor without any issues.

Expected behavior and actual behavior:

This issue has been faced wile setting up a replication from the GitLab Container Registry (GLCR) to the Harbor one.

Some of the docker images stored in the GLCR have name similar to the following: <registry URL>/<namespace>/<project>/<image>:tag

E.g., Image to replicate (GLCR):registry.example.com/group/project/image:latest This project needs to be replicated into the following Harbor project: <Harbor registry URL>/<namespace>/<project>/<image>:tag

Expected behavior

Harbor successfully does the pull-cased replication of the Docker image <registry URL>/<namespace>/<project>/<image>:tag to a <Harbor registry URL>/<namespace>/<project>/<image>:tag without any issues.

Actual behavior

Harbor fails the replication (Error) of the Docker image <registry URL>/<namespace>/<project>/<image>:tag to a <Harbor registry URL>/<namespace>/<project>/<image>:tag.

It is also looks like this causes DoS for the Harbor node as all the CPU and RAM resources are drained.

Steps to reproduce the problem:

1. Create a GitLab Project in some Group and push into it a Docker image with the following name <registry URL>/<namespace>/<project>/<image>:tag. I assume might also be true for other Docker Registries.
2. Setup a replication in Harbor to replicate <namespace>/** from GitLab to a Harbor.
3. Run the replication.
4. Replication will fail without having <registry URL>/<namespace>/<project>/<image>:tag.
5. If many projects should be replicated, the replication of the <registry URL>/<namespace>/<project>/<image>:tag image will cause DoS for the Harbor.

Versions:

Please specify the versions of following systems.

• harbor version: [v2.1.0]

Additional context:

Harbor error log

2020-10-26T14:08:16Z [ERROR] [/replication/transfer/image/transfer.go:175]: Get "https://<registry URL>/jwt/auth?scope=repository%!A(MISSING)<namespace>%!F(MISSING)<project>%!F(MISSING)<image>%!A(MISSING)pull&service=container_registry": dial tcp: lookup <registry URL> on 127.0.0.11:53: read udp 127.0.0.1:55739->127.0.0.11:53: i/o timeout