prometheus-adapter/vendor/github.com/docker/distribution/contrib/compose/nginx/docker-registry-v2.conf

proxy_pass                          http://docker-registry-v2;
proxy_set_header  Host              $http_host;   # required for docker client's sake
proxy_set_header  X-Real-IP         $remote_addr; # pass on real client's IP
proxy_set_header  X-Forwarded-For   $proxy_add_x_forwarded_for;
proxy_set_header  X-Forwarded-Proto $scheme;
proxy_read_timeout                  900;