Islandora/Fedora requirements

a2enmod headers
service apache2 restart

nano -w /etc/apache2/sites-enabled/archive.digibess.eu.conf


        AllowEncodedSlashes On
        ProxyRequests Off
        ProxyPreserveHost On
        <Proxy *>
                Order deny,allow
                Allow from all
        </Proxy>

+        RequestHeader set X-Forwarded-Path /iiif-server
+        ProxyPass /iiif-server http://123.123.123.123:8182 nocanon
+        ProxyPassReverse /iiif-server http://123.123.123.123:8182
Image Server = IIIF Image server

IIIF Image Server Base URL = http://archive.digibess.eu/iiif-server/iiif/2

If yuo plan to redirect Tile source URL from front-end to directly back-end, you need to add Image Server IP to /usr/local/fedora/data/fedora-xacml-policies/repository-policies/default/deny-apim-if-not-localhost.xml

By default tile source point to front-end server to download JP2. In some case pointing directly to fedora may result in better performance.
To modify how this works you can add to your theme template.php this function to override tile source URL for islandora openseadragon (Many thanks Nigel!!):

function beginning_preprocess_islandora_openseadragon_viewer(array &$variables) {
  module_load_include('inc', 'islandora_openseadragon', 'includes/utilities');
  $pid =  $variables['settings']['pid'];
  $matches = array();
  preg_match('/datastream%2[fF](.*)%2[fF]view/', $variables['settings']['options']['tileSources'][0], $matches);
  $dsid = isset($matches[1]) ? $matches[1] : NULL;
  $identifier = "http://FEDORA_IP_or_FQDN:8080/fedora/objects/".$pid."/datastreams/".$dsid."/content";
  $variables['settings']['options']['tileSources'] = islandora_openseadragon_identifier_tile_source($identifier);
}

This function replaces tile source URL and remove token, so IIIF server download directly from fedora avoiding network loop with front-end.

NOTE: UPGRADE to CANTALOUPE 3.4