nginx.conf

user www-data;
worker_processes 1;

error_log /var/log/nginx/error.log warn;
pid       /var/run/nginx.pid;

events {
    worker_connections 1024;
}

http {

    upstream backend {
      server app-server:8080;
    }

    include      /etc/nginx/mime.types;
    default_type application/octet-stream;

    log_format main '$remote_addr - $remote_user [$time_local] "$request" '
                    '$status $body_bytes_sent "$http_referer" '
                    '"$http_user_agent" "$http_x_forwarded_for"';

    access_log /var/log/nginx/access.log main;

    keepalive_timeout 65;

    map $http_host $this_host {
        "" $host;
        default $http_host;
    }

    map $http_x_forwarded_proto $the_scheme {
        default $http_x_forwarded_proto;
        "" $scheme;
    }

    map $http_x_forwarded_host $the_host {
       default $http_x_forwarded_host;
       "" $this_host;
    }

    server {
        listen 80;

        client_max_body_size 10G;
        fastcgi_buffers 64 4K;

        index index.php;

        location / {
            proxy_pass http://backend;

            proxy_set_header Host $http_host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Host $the_host;
            proxy_set_header X-Forwarded-Proto $the_scheme;
        }

        location ~* ^/ds-vpath/ {
            add_header Strict-Transport-Security "max-age=15768000; includeSubDomains; preload;";
            add_header X-Content-Type-Options nosniff;
            add_header X-XSS-Protection "1; mode=block";
            add_header X-Robots-Tag none;
            add_header X-Download-Options noopen;
            add_header X-Permitted-Cross-Domain-Policies none;
                        
            rewrite /ds-vpath/(.*) /$1 break;
            proxy_pass http://onlyoffice-document-server;
            proxy_redirect off;

            client_max_body_size 100m;

            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";

            proxy_set_header Host $http_host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Host $the_host/ds-vpath;
            proxy_set_header X-Forwarded-Proto $the_scheme;
        }
    }
}