chore: import upstream snapshot with attribution

api/http/handler/registries/proxy_gitlab.go

@@ -0,0 +1,23 @@
+package registries
+
+import (
+	"net/http"
+
+	httperror "github.com/portainer/portainer/pkg/libhttp/error"
+)
+
+// request on /api/registries/proxies/gitlab
+func (handler *Handler) proxyRequestsToGitlabAPIWithoutRegistry(w http.ResponseWriter, r *http.Request) *httperror.HandlerError {
+	domain := r.Header.Get("X-Gitlab-Domain")
+	if domain == "" {
+		return httperror.BadRequest("No Gitlab domain provided", nil)
+	}
+
+	proxy, err := handler.ProxyManager.CreateGitlabProxy(domain)
+	if err != nil {
+		return httperror.InternalServerError("Unable to create gitlab proxy", err)
+	}
+
+	http.StripPrefix("/registries/proxies/gitlab", proxy).ServeHTTP(w, r)
+	return nil
+}