How to start nginx when there is no docker swarm service?

Question

Nginx

There is a docker swarm orchestrator and nginx inside for proxying requests.

upstream site {
  server site:3000;
}

The problem occurs when the docker swarm site service does not start or starts after the nginx service . As a result, nginx doesn't start at all because the site name doesn't resolve .
Maybe somehow you can reduce the anxiety of this setting so that nginx still starts and sends requests when the service comes to life?

Answer 1

It looks like the only option is not to specify upstreams, but to declare them in the location directive along with the resolver.
https://ilhicas.com/2018/04/14/Nginx-Upstream-Unav...

location / {
           resolver 8.8.8.8 valid=10s;
           set $upstreamName nameofhost:8443;
           proxy_pass http://$upstreamName;

But if nginx-vts statistics are used , then upstream metrics will not be considered.
Therefore, in general, docker swarm + nginx + nginx_vts + prometheus is a road to nowhere.
As an option, try traefik as a replacement for nginx.