Any way to check a repository similar to the registry ping?

[psheichelberg]

I have a Harbor registry with a public repository, lets say harbor.example.com/path/to/my/repository. I want to use this repository for an Argo CD Application.

Argo CD uses func (*Registry) Ping to test if a given URL is an OCI registry. Unfortunately this fails with 401 Unauthorized, because Ping() sends a request to /v2/, Harbor responds with the Www-Authenticate header and Ping() uses the information from this header to make a request to /service/token and this fails without credentials. If this second request would be scoped (scope=repository:path/to/my/repository:pull) it would succeed, because the repository is public.

I think Ping() is (probably) not doing anything wrong here. But I am wondering if there is a better way for Argo CD to check the repository.

Maybe by using the func (*Repository) Tags?

// rough draft
registry, err := remote.NewRegistry(registryHost)
if err != nil { 
	// …
}

repository, err := registry.Repository(ctx, strings.TrimPrefix(repositoryPath, "/"))
if err != nil { 
	// …
}

funcTags := func(tags []string) error { return nil }
err = repository.Tags(ctx, "", funcTags)
if err != nil { 
	// …
}

Or maybe this is a request for a new func (*Repository) Ping in oras-go which could be used to check a repository. 😅

Thank you in advance! ❤️