Nginx – disadvantage to running nginx on a VM

There are actually 4 sets of Locally Administered Address Ranges that can be used on your network without fear of conflict, assuming no one else has assigned these on your network:

x2-xx-xx-xx-xx-xx
x6-xx-xx-xx-xx-xx
xA-xx-xx-xx-xx-xx
xE-xx-xx-xx-xx-xx

Replacing x with any hex value.

Apache will still serve static files, but it will only serve them once. Perhaps the easiest way is to configure varnish to listen on all IP addresses for port 80, and configure Apache to listen to on localhost:8000 for example. Then you configure varnish to forward all requests it receives to localhost:8000 for Apache to handle.

I would go with a varnish configuration of:

# have varnish listen on port 80 (all addresses)
varnishd -a 0.0.0.0:80

Now within your vcl file:

backend default {
  .host = "localhost";
  .port = "8000";
}

sub vcl_recv {
  # add a unique header containing the client IP address
  set req.http.X-Orig-Forwarded-For = client.ip;

  # we're only handling static content for now so remove any
  # Cookie that was sent in the request as that makes caching
  # impossible.
  if (req.url ~ "\.(jpe?g|png|gif|ico|js|css)(\?.*|)$") {
    unset req.http.cookie;
  }
}

vcl_fetch {
  # if the backend server adds a cookie to all responses,
  # remove it from static content so that it can be cached.
  if (req.url ~ "\.(jpe?g|png|gif|ico|js|css)(\?.*|)$") {
    unset obj.http.set-cookie;
  }
}

Now within your Apache httpd.conf configuration, you want Apache to listen on localhost:8000 and define your virtual hosts on the same address:port

Listen 127.0.0.1:8000
NameVirtualHost 127.0.0.1:8000

For each website, create a <VirtualHost> stanza. Within that stanza you need to tell Apache to set the Expires and cache-control headers on all static content so varnish knows to cache it.

<VirtualHost 127.0.0.1:8000>
  ServerName www.our-example-domain.com

  # Set expires and cache-control headers on static content and
  # tell caches that the static content is valid for two years
  ExpiresActive on

  <FilesMatch "\.(js|css|ico|gif|png|jpe?g)$">
    ExpiresDefault "access plus 2 year"
    Header append Cache-Control "public"
  </FilesMatch>

  # ... the rest of your web site configuration ...
</VirtualHost>

I hope this helps.