Image retag function

[cd1989]

Is your feature request related to a problem? Please describe.

For the moment, if I want to retag an image in Harbor with another tag, the only way seem to executing:

• docker pull ...
• docker tag ...
• docker push ...

This is very insufficient to pull a large image, it's more reasonable to achieve retag within the Harbor.

There are several scenarios when user may want to retag an image:

1. Retag fully tested images from stage project to product project
2. Retag a latest dated tag to latest, for example, app:201809011830 --> app:latest
3. ...

Describe the solution you'd like

Harbor can provide an API to support retag an image, and may also to support it in UI. Then user can:

• Create new tag for an image
• Move images across projects within Harbor

Describe the main design/architecture of your solution

POST /api/retag

{
    "src_image": "stage/app:v1.0",
    "dest_image": "product/app:v1.0"
}

User can retag images to other project, or repo as long as it's permitted

For retag, there is no layer data transfer, so it should be efficient enough.

Describe the development plan you've considered

I'd like this can be achieved in v1.6.0. I will make a PR soon if it's accepted.

Additional context
Add any other context or screenshots about the feature request here.

[reasonerjt]

@cd1989 thanks a lot for the proposal.

1. For more flexibility and simplicity, how about provide an API to PUT a tag with given SHA256?

2. It may be better to put the url of the target tag in the url of the API so it'd easier for auth checking based on url. In future we may introduce a layer for that.

[cd1989]

@reasonerjt thanks for the suggestions.

For more flexibility and simplicity, how about provide an API to PUT a tag with given SHA256?

I'm not clear of this, can this tag to another repo or project.

It may be better to put the url of the target tag in the url of the API so it'd easier for auth checking based on url. In future we may introduce a layer for that.

You means API like:

POST /api/repositories/<target-repo>/tags/<target-tag>?from=<source-image>
e.g. /api/repositories/product/app/tags/v1.0?from=stage/app:v1.0

[reasonerjt]

@cd1989
In your proposal, upon receiving the request, the backend will read the manifest of the source-image before calling the API of registry.

In concurrent situation, there's a gap between client triggering the request and backend handling the request, where the source image may change.

So how about the API looks like this:
PUT /api/repositories/<target-repo>/tags/<target-tag>
with request body:

{
    "digest":"sha256:9e2c9d5f44efbb6ee83aecd17a120c513047d289d142ec5738c9f02f9b24ad07"
}

Seems it will more convenient that registry can provide an API so the manifest does not need to be pushed again. I'm open for discussion about it anyway...

[cd1989]

@reasonerjt Thank you for the details.

PUT /api/repositories/<target-repo>/tags/<target-tag>

PUT is commonly used to update something, here it's tag. But what the API want to do is to create, so I think POST is better.

About the gap problem, I agree it's a problem and digest is better.

[cd1989]

So how about:

POST /api/repositories/<target-repo>/tags/<target-tag>
{
	"src_repo": "stage/app",
	"src_digest": "sha256:9e2c9d5f44efbb6ee83aecd17a120c513047d289d142ec5738c9f02f9b24ad07",
}

[steven-zou]

@cd1989

If the operation is creating a new tag of the repo, I think it should be

POST /api/repositories/<target-repo>/tags
{
	"src_repo": "stage/app",
	"src_digest": "sha256:9e2c9d5f44efbb6ee83aecd17a120c513047d289d142ec5738c9f02f9b24ad07",
      "tag: <target-tag>
}

[steven-zou]

@cd1989

As you're doing the implementation of this feature, I'll assign you as the owner of this proposal.

[reasonerjt]

So we will only support retag to a new tag? Not retag to a existing tag?
I don't think it's necessary to include the src_repo in the request.

[cd1989]

I don't think it's necessary to include the src_repo in the request.

What I want to achieve is to retag an image to:

• a new tag in the same repo
• a tag in a new repo

To retag across repos, it's necessary to specify the source repo, the url only gives the target repo