How to configure nginx to block access to the site and direct to the stub during maintenance?

Question

Nginx

There is a big nginx config with different location and proxy_pass on httpd. It is necessary to cut off httpd for a while and redirect all requests to a static page (stub) in another directory. What and where to write in the config for this?

Answer 1

An example of implementing a stub output when the backend is unavailable:

error_page 502 503 504 /maintenance.htm;
location ~ /maintenance\.(css|htm|jpg) {
        root /usr/share/nginx;
}

This preserves the original address of the request. Another convenience is that these parameters can be put in a separate file and connected as needed via include for any set of sites. Additionally, you can organize automatic page reloading, for example, by adding the following line to the maintenance.htm file:
<meta http-equiv="refresh" content="30" />

Answer 2

location / {
    return 302 site.com/stub.html;
}

before all locations