This is how to set up a subdomain reverse proxy

venanti.us_nginx

server {
	listen 80;
    server_name blog.venanti.us;

	location / {
        proxy_pass http://85.17.164.147:2368;
    		# This should be changed in the future to send to 127.0.01
        # but for now Ghost isn't configured for that
	}

}

#FWIW I cannot for the life of me figure out how to make this work on venanti.us/blog instead of blog.venanti.us, so bah humbug.
#I think, though, that if one were to do such a thing, it would look vaguely like this:
# After further poking around, it seems Ghost simply doesn't support doing this. There are hacky ways to make it work, but none of them look particularly good.

server {
	listen 80;
    server_name venanti.us;

  location / {
    # Some stuff goes here eventually
  }

	location /blog/ {
	      include /etc/nginx/mime.types;
	      rewrite ^/blog(/.*)$ $1 break;
        proxy_pass http://85.17.164.147:2368;
    		# This should be changed in the future to send to 127.0.01
        # but for now Ghost isn't configured for that
	}

}