How to make a temporary stub for the site

Question

Nginx

There is a working site. It is necessary to put a stub page for several days, in which there will be only a feedback form. Tell me how to correctly register a redirect in nginx for a virtual host so that all incoming requests go to this page and somehow mark for search robots that this is a temporary page. Well, so that the page rating does not fall there and all that.

Answer 1

In any case, this will not go unnoticed for the PS.
If literally 1-2 days, then you can give a 503 error.
And with any redirect, for PS it is a sign of moving content (permanently or temporarily). Accordingly, on the page to which the redirect leads, the PS will expect content - which is not there. What is wrong.
In such cases, I don’t touch the main site, but I do all the work in a different folder, with a different domain / subdomain, closed from indexing by robots. And then I just change the path for the folder with the site.

Answer 2

To mark for search engines so that the rating does not fall, as far as I know, it is enough to give 503 code.

Answer 3

Do I need to write something in robots.txt?