Add Docker /v2/_catalog endpoint (#20469)

* Added properties for packages.
* Fixed authenticate header format.
* Added _catalog endpoint.
* Check owner visibility.
* Extracted condition.
* Added test for _catalog.

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: Lauris BH <lauris@nix.lv>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

models/packages/package.go

@@ -131,6 +131,12 @@ func TryInsertPackage(ctx context.Context, p *Package) (*Package, error) {
 	return p, nil
 }
 
+// DeletePackageByID deletes a package by id
+func DeletePackageByID(ctx context.Context, packageID int64) error {
+	_, err := db.GetEngine(ctx).ID(packageID).Delete(&Package{})
+	return err
+}
+
 // SetRepositoryLink sets the linked repository
 func SetRepositoryLink(ctx context.Context, packageID, repoID int64) error {
 	_, err := db.GetEngine(ctx).ID(packageID).Cols("repo_id").Update(&Package{RepoID: repoID})
@@ -192,21 +198,20 @@ func GetPackagesByType(ctx context.Context, ownerID int64, packageType Type) ([]
 		Find(&ps)
 }
 
-// DeletePackagesIfUnreferenced deletes a package if there are no associated versions
-func DeletePackagesIfUnreferenced(ctx context.Context) error {
+// FindUnreferencedPackages gets all packages without associated versions
+func FindUnreferencedPackages(ctx context.Context) ([]*Package, error) {
 	in := builder.
 		Select("package.id").
 		From("package").
 		LeftJoin("package_version", "package_version.package_id = package.id").
 		Where(builder.Expr("package_version.id IS NULL"))
 
-	_, err := db.GetEngine(ctx).
+	ps := make([]*Package, 0, 10)
+	return ps, db.GetEngine(ctx).
 		// double select workaround for MySQL
 		// https://stackoverflow.com/questions/4471277/mysql-delete-from-with-subquery-as-condition
 		Where(builder.In("package.id", builder.Select("id").From(in, "temp"))).
-		Delete(&Package{})
-
-	return err
+		Find(&ps)
 }
 
 // HasOwnerPackages tests if a user/org has packages