nginx service start needs to wait dns service

When using nginx as reverse proxy you can have one or more upstream server set up with a hostname instead of its IP address like this:

upstream myUpstream {
   server this-host-needs-dns-to-be-resolved.com;
}

If nginx it's started *before* the DNS subsystem it's working nginx won't be started because it cannot resolve the this-host-needs-dns-to-be-resolved.com hostname.

# systemctl status nginx
● nginx.service - A high performance web server and a reverse proxy server
     Loaded: loaded (/lib/systemd/system/nginx.service; enabled; vendor preset: enabled)
     Active: failed (Result: exit-code) since Tue 2023-06-06 06:45:48 CEST; 20s ago
       Docs: man:nginx(8)
    Process: 561 ExecStartPre=/usr/sbin/nginx -t -q -g daemon on; master_process on; (code=exited, status=1/FAILURE)

Jun 06 06:45:48 ip-172-31-9-7 systemd[1]: Starting A high performance web server and a reverse proxy server...
Jun 06 06:45:48 ip-172-31-9-7 nginx[561]: nginx: [emerg] host not found in upstream "this-host-needs-dns-to-be-resolved.com>
Jun 06 06:45:48 ip-172-31-9-7 nginx[561]: nginx: configuration file /etc/nginx/nginx.conf test failed
Jun 06 06:45:48 ip-172-31-9-7 systemd[1]: nginx.service: Control process exited, code=exited, status=1/FAILURE
Jun 06 06:45:48 ip-172-31-9-7 systemd[1]: nginx.service: Failed with result 'exit-code'.
Jun 06 06:45:48 ip-172-31-9-7 systemd[1]: Failed to start A high performance web server and a reverse proxy server.

To fix this we need to set on systemd some other targets to be waited before the nginx service it's started.

I tried with this change but it doesn't worked.

# diff /etc/systemd/system/multi-user.target.wants/nginx.service /etc/systemd/system/multi-user.target.wants/nginx.service_new
16c16
< After=network.target
---
> After=network-online.target nss-lookup.target

I fixed it setting an ip address on the upstream but I think a simple bug like this should be fixed.

Regards,