nginx.conf

# Change YOUR_TOKEN to your prerender token
# Change example.com (server_name) to your website url
# Change 127.0.0.1:3000 to the backend address

worker_processes  1;

events {
    worker_connections  1024;
}

http {

    map $http_user_agent $prerender_ua {
        default       0;
        "~*Prerender" 0;

        "~*googlebot"                               1;
        "~*yahoo!\ slurp"                           1;
        "~*bingbot"                                 1;
        "~*yandex"                                  1;
        "~*baiduspider"                             1;
        "~*facebookexternalhit"                     1;
        "~*twitterbot"                              1;
        "~*rogerbot"                                1;
        "~*linkedinbot"                             1;
        "~*embedly"                                 1;
        "~*quora\ link\ preview"                    1;
        "~*showyoubot"                              1;
        "~*outbrain"                                1;
        "~*pinterest\/0\."                          1;
        "~*developers.google.com\/\+\/web\/snippet" 1;
        "~*slackbot"                                1;
        "~*vkshare"                                 1;
        "~*w3c_validator"                           1;
        "~*redditbot"                               1;
        "~*applebot"                                1;
        "~*whatsapp"                                1;
        "~*flipboard"                               1;
        "~*tumblr"                                  1;
        "~*bitlybot"                                1;
        "~*skypeuripreview"                         1;
        "~*nuzzel"                                  1;
        "~*discordbot"                              1;
        "~*google\ page\ speed"                     1;
        "~*qwantify"                                1;
        "~*pinterestbot"                            1;
        "~*bitrix\ link\ preview"                   1;
        "~*xing-contenttabreceiver"                 1;
        "~*chrome-lighthouse"                       1;
        "~*telegrambot"                             1;
        "~*google-inspectiontool"                   1;
        "~*petalbot"                                1;
    }

    map $args $prerender_args {
        default $prerender_ua;
        "~(^|&)_escaped_fragment_=" 1;
    }

    map $http_x_prerender $x_prerender {
        default $prerender_args;
        "1"     0;
    }

    map $uri $prerender {
        default $x_prerender;
        "~*\.(js|css|xml|less|png|jpg|jpeg|gif|pdf|txt|ico|rss|zip|mp3|rar|exe|wmv|doc|avi|ppt|mpg|mpeg|tif|wav|mov|psd|ai|xls|mp4|m4a|swf|dat|dmg|iso|flv|m4v|torrent|ttf|woff|woff2|svg|eot)" 0;
    }


    server {
        listen 80;
        server_name example.com;

        location / {
            if ($prerender = 1) {
                rewrite (.*) /prerenderio last;
            }

            proxy_set_header Host $SERVER_NAME;
            proxy_set_header Connection "";
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

            proxy_hide_header Cache-Control;
            add_header Cache-Control "public,max-age=31536000";

            #resolve using Google's DNS server to force DNS resolution and prevent caching of IPs
            resolver 8.8.8.8 8.8.4.4;

            #setting backend as a variable forces DNS resolution since nginx caches IPs and doesnt play well with load balancing
            set $backend "127.0.0.1:3000";

            rewrite .* $uri break;
            proxy_pass http://$backend;
        }

        location /prerenderio {
            if ($prerender = 0) {
                return 404;
            }

            proxy_set_header X-Prerender-Token YOUR_TOKEN;
            proxy_set_header X-Prerender-Int-Type Nginx_Rev_Proxy;

            proxy_hide_header Cache-Control;
            add_header Cache-Control "private,max-age=600,must-revalidate";

            #resolve using Google's DNS server to force DNS resolution and prevent caching of IPs
            resolver 8.8.8.8 8.8.4.4;
            set $prerender_host "service.prerender.io";
            proxy_pass https://$prerender_host;
            rewrite .* /$scheme://$host$request_uri? break;
        }
    }
}