Reverse proxy Nginx config for Heroku app

nginx.conf.erb

daemon off;
worker_processes <%= ENV['NGINX_WORKERS'] || 4 %>;

events {
	worker_connections 1024;
}

http {
	upstream my_nginx {
		server unix:/tmp/nginx.socket fail_timeout=0;
	}

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

	sendfile on;
	tcp_nopush on;
	tcp_nodelay on;
	keepalive_timeout 300;
	send_timeout 10;

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

	access_log logs/nginx/access.log;
	error_log logs/nginx/error.log;

	gzip on;
	gzip_disable "msie6";
	gzip_min_length 256;
	gzip_proxied any;
	gzip_comp_level 5;
	gzip_buffers 16 8k;
	gzip_http_version 1.1;

	gzip_types  application/ecmascript;
	gzip_types  application/javascript;
	gzip_types  application/json;
	gzip_types  application/xml;
	gzip_types  application/x-javascript;
	gzip_types  image/svg+xml;
	gzip_types  text/css;
	gzip_types  text/javascript;
	gzip_types  text/plain;
	gzip_types  text/xml;

	server {
		listen <%= ENV["PORT"] %> default_server;
		client_max_body_size 30M;
		server_name _;

		root /app/;

		location / {
			expires epoch;
			proxy_pass http://my_nginx;
			proxy_set_header Host $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-Proto $scheme;
			add_header X-Frame-Options SAMEORIGIN;
			add_header X-XSS-Protection "1; mode=block";
		}

		location ~ \.(css|js)$ {
			add_header Pragma "public";
			add_header Cache-Control "max-age=2628000, public, must-revalidate, proxy-revalidate";
			add_header Access-Control-Allow-Origin *;
			add_header X-Frame-Options SAMEORIGIN;
			add_header X-XSS-Protection "1; mode=block";
			access_log off;

		}
		
		location ~ \.(gif|jpg|png|ico|woff|tff)$ {
			add_header Pragma "public";
			add_header Cache-Control "max-age=31536000, public, must-revalidate, proxy-revalidate";
			add_header Access-Control-Allow-Origin *;
			add_header X-Frame-Options SAMEORIGIN;
			add_header X-XSS-Protection "1; mode=block";
			access_log off;
		}

		location ~ ^/(sitemap.xml) {
			root /app/public;
		}

		# Turn off logging for them
		location = /favicon.ico { log_not_found off; access_log off; }
		location = /robots.txt  { log_not_found off; access_log off; }
	}
}