README.txt in Authenticated User Page Caching (Authcache) 7.2

INSTALLATION
============

* Install and enable authcache and authcache_varnish modules.
* Navigate to Administration » Configuration » Development and set "Expiration
  of cached pages" to an appropriate value (> 0).
* Install and enable the varnish and expire modules in order to have means to
  invalidate the cache when necessary.
* The example.vcl file includes snippets of code to add to your Varnish
  configuration to make authcache_varnish work. If you have an existing
  Varnish configuration file, it is recommended to start with example.vcl
  and add bits from your own file to it.
* Optionally enable authcache_debug. Uncommenting the appropriate lines in
  vcl_deliver in order to make the cache-hit indicator on the debug widget
  work.

The module and the VCL is based on the ideas of Josh Waihi. Please refer to
his excellent blog post for further background:
* http://joshwaihi.com/content/authenticated-page-caching-varnish-drupal

Detailed documentation with screenshots and additional notes is available
online in the Drupal Administration & Security Guide:
* https://www.drupal.org/node/2162047

The test folder contains a test-suite for the example.vcl. Run it by issuing
"make check". If you like to test your own version of the VCL, point the
AUTHCACHE_VCL variable to your file, e.g.:

    make check AUTHCACHE_VCL_FILE=/path/to/my/authcache.vcl


SETTINGS
========

Authcache Varnish verifies whether a request is coming in through a trusted
proxy server. Therefore it is necessary to properly configure reverse proxy
support in settings.php. E.g:

    $conf['reverse_proxy'] = TRUE;
    $conf['reverse_proxy_addresses'] = array('a.b.c.d');
    // Replace 'a.b.c.d' with the IP address of the reverse proxy server.

Some web servers restore the original client IP address before before handing
over the request to PHP/Drupal, e.g. Nginx when configured with the real_ip
module. In this case a shared secret can be configured in settings.php as well
as in the vcl_miss() subroutine.

    $conf['authcache_varnish_passphrase'] = 'correct horse battery staple';

For testing purposes it is possible to disable the reverse proxy check by
placing the following line into the settings.php file:

    $conf['authcache_varnish_validate_reverse_proxy_address'] = FALSE;

Beside the reverse proxy address Authcache Varnish also tests whether the
X-Varnish header is on the request. In order to disable this check, place the
following line into settings.php:

    $conf['authcache_varnish_header'] = FALSE;

Also it is possible to specify another header which should be checked by
specifying the $_SERVER-key accordingly. E.g. when Authcache Varnish should
verify the presence of X-Fancy-Proxy, introduce the following line into your
settings.php:

    $conf['authcache_varnish_header'] = 'HTTP_X_FANCY_PROXY';