Support project auto sync feature by pull-based replication mode

[yunkunrao]

Signed-off-by: yunkunrao yunkunrao@gmail.com

Summary

This PR adds event-based trigger mode for pull-based replication mode. This PR is related with #14736 .

Background

Briefly, current replication policy doesn't support event-based trigger mode for pull-based replication mode.
And alternative solution proxy cache seems to have a similar function, but it has it's own limitation that docker image namespace has to be changed with a new proxy cache project as the prefix.

Solution

Harbor admin can create a project with the same project name as the upsteam Harbor's project name with specified upstream registry_id and enable auto sync option.

When client run the docker pull cmd, local harbor will synchronize the docker image automically in the project. In other words it's totally transparent to docker client without any prefix in docker image full name.

For example, if we want to pull the latest image from downstream Harbor

• For proxy cache, we can run docker pull <downstream_harbor:port>/proxy/<your ns>/<your image>:latest
• For pull-based replication mode, we can run docker run <downsteam_harbor:port>/<your ns>/<your image>:latest. Only prerequisites are project name should be the same as upstream's project name and project enable auto-synced option.

[yunkunrao]

Proposal was submitted, please refer to goharbor/community#169

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[github-actions]

This PR was closed because it has been stalled for 30 days with no activity. If this PR is still relevant, please re-open a new PR against main.