NGX-878: Update Nginx Site Configuration (#72)

Add two additional pieces of logic into the server hostname block.
  - Requests to 'wp-json' are able to be proxied as if the request was made to the site url
  - Requests with the 'rest_route' query string are able to be proxied as if the request was made to the site url

All other requests to the server hostname will not be proxied as if they were made to the site url.  This prevents the entire WordPress site from being accessible over the server hostname.

templates/etc/nginx/conf.d/site.conf.j2

@@ -20,6 +20,15 @@ server {
     location / {
         add_header X-Proxy-Cache $upstream_cache_status;
 
+        # If the 'rest_route' query parameter is not defined or is empty,
+        # perform a 301 (permanent) redirect to the same URI on the site domain,
+        # preserving the scheme (http or https) and the request URI, preventing
+        # the site from loading on the server hostname but allowing rest_route
+        # to be accessed over the hostname
+        if ($arg_rest_route = "") {
+            return 301 $scheme://{{ site_domain }}$request_uri;
+        }
+
         proxy_set_header Host $http_host;
         proxy_set_header X-Real-IP $remote_addr;
         proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
@@ -57,6 +66,25 @@ server {
         }    
     }
 {% endif %}
+    # allow 'wp-json' to be accessed over the server hostname
+    location ~ ".*/wp-json" {
+        add_header X-Proxy-Cache $upstream_cache_status;
+
+        proxy_set_header Host $http_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-Host {{ site_domain }};
+        proxy_set_header X-Forwarded-Server {{ site_domain }};
+
+        proxy_no_cache 1;
+        proxy_cache_bypass 1;
+
+        proxy_pass https://apache_ssl;
+
+        proxy_http_version 1.1;
+        proxy_set_header Connection "";
+    }
+
 }
 {% endif %}