Using Nginx as a reverse-proxy for Node and Apache

I recently migrated my blog from Wordpress to Ghost, but I wanted to maintain my old blog posts on Wordpress (check this out for more background information). As such, I needed to configure my server to run the two different web platforms through a similar route-subdirectory. Here's how I did it:

The environment

I installed Wordpress on a new Ubuntu EC2 instance, in the directory /var/www/blog/. After importing my of my old posts, my Wordpress posts followed this slug format:

http://thecalvinchan.com/blog/%year/%month/%date/%title/

Ghost was also installed on the same EC2 instance. To maintain as much consistency as I could, I still wanted to serve Ghost posts through the /blog subdirectory. My Ghost posts follow this slug format:

http://thecalvinchan.com/blog/%title/

Since all http requests go through port 80, I needed to find a way to route certain requests to Apache (which ran Wordpress) and certain requests to Node (which ran Ghost). I decided to use Nginx to proxy requests to their respective platforms.

(I decided to install another http server to proxy requests to their respective servers. However, you can easily achieve this same result by simply configuring Apache to proxy certain requests to Node)

The configuration

Apache

First, we must configure Apache to listen on requests through a different port (port 80 must be open for Nginx to listen to).

File: /etc/apache2/ports.conf

// - denotes delete line and + denotes add line
- NameVirtualHost *:80
- Listen 80
+ NameVirtualHost *:8080
+ Listen 8080

File: /etc/apache2/sites-available/%your-site-configuration-file

- <VirtualHost *:80>
+ <VirtualHost *:8080>

What we've done is changed Apache to listen on port 8080 instead of 80. We should be done with all Apache configurations, assuming the prior configuration was default.

Node

By default, Ghost configures Node to listen on port 2368. You don't need to change this.

Nginx

Since we've changed Apache to listen on port 8080, Nginx can now listen to all http requests on port 80. We now need to configure it to proxy certain requests to Apache and other requests to Node. Go ahead and just copy and paste the following into your Nginx site configuration file. I've commented certain sections to explain what the code does.

File: /etc/nginx/sites-available/%your-site-configuration-file

server {
  listen 80;
  root /var/www/;
  index index.php index.html index.htm;
  server_name example.com;

  // By default, all files are served through Nginx
  location / {
    try_files $uri $uri/ $uri/index.php /index.php;
  }

  // If the route uri matches a Wordpress uri or is a php file, proxy to Apache
  location ~ (/blog/[0-9]+/|/blog/wp-.*/|\.php$) {
    proxy_set_header    X-Real-IP   $remote_addr;
    proxy_set_header    X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header    Host        $http_host;
    proxy_set_header    X-NginX-Proxy   true;
    proxy_pass        http://127.0.0.1:8080;
    proxy_redirect off;
  }

  // If the route uri matches a Ghost uri, proxy to Node
  location ~ /blog/? {
    proxy_set_header     X-Real-IP   $remote_addr;
    proxy_set_header    X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header    Host        $http_host;
    proxy_set_header    X-NginX-Proxy   true;

    proxy_pass        http://127.0.0.1:2368;
    proxy_redirect off;
  }

  location ~ /\.ht {
    deny all;
  }
}

The two lines of interest are:

location ~ (/blog/[0-9]+/|/blog/wp-.*/|\.php$)

and

location ~ /blog/?

These two lines use Perl formatted regular expressions to match certain requests. Because my Wordpress slugs start with the year and follow this format:

http://thecalvinchan.com/blog/%year/%month/%date/%title/

we can use a regular expression to match URIs with /blog/[0-9]+/ and proxy those requests to Apache. Additionally, we proxy all Wordpress specific requests matching blog/wp-.*/ to Apache as well. Assuming Ghost slugs don't start with a date, we can proxy all the other /blog requests to Node.

Where this falls short

This solution is very dependent on the fact that my Wordpress slugs followed the /blog/%year/%month/%date/%title format. Because I am in control of my newer Ghost slugs, I can ensure that there will be no cross-match between the new slugs and the old slugs. However, this solution can be compromised if any new Ghost slug consists of only numeric characters. Alas, this is only a short-term solution to running both Wordpress and Ghost. Ideally, in the future, I can import my existing Wordpress posts to Ghost and simplify the http stack.