Nginx prerender

nginx.conf

http {
    include       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  logs/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    #keepalive_timeout  0;
    keepalive_timeout  65;

    #gzip  on;

map $http_user_agent $prerender_ua {
	default			"0";
	"~baiduspider"		"1";
	"~twitterbot"		"1";
	"~facebookexternalhit"	"1";
	"~rogerbot"		"1";
	"~linkedinbot"		"1";
	"~embedly"		"1";
	"~quora link preview"	"1";
	"~showyoubot"		"1";
	"~outbrain"		"1";
	"~pinterest"		"1";
	"~slackbot"		"1";
}   

map $uri $prerender {
	default			"$prerender_ua";
	"~_escaped_fragment_"	"1";
}

map $prerender $route {
	"0"			"@default";
	"1"			"@prerender";
}


server {
	listen		9999;
	server_name	localhost;
	
	set 		$mainuri	"http://www.mywebpage.com";

	location @default {
	    resolver 8.8.8.8;
	    proxy_pass  $mainuri;
	    add_header	X-Route	default;
	}

	location @prerender {
		add_header	X-Route	prerender;
		rewrite 	^(.*)$	/$mainuri$1?$args break;
		
		# Proxy uri to running prerender.io instance
		proxy_pass	http://127.0.0.1:3000;
	}

	location / {
	    content_by_lua '
	    	ngx.exec(ngx.var.route)
	    ';
	}
    }
}