add varnish configuration

Author: eloiferrer

LocalSettings.d/base/LocalSettings.override.php

@@ -189,7 +189,7 @@
 $wgCacheDirectory = "$IP/cache/$wgDBname";
 
 // speed up speed for anonymous users https://www.mediawiki.org/wiki/Manual:$wgUseFileCache
-$wgUseFileCache=true;
+$wgUseFileCache=false;
 
 // speed up article count, by reducing the number of queries to the (giant) pagelink tables
 $wgArticleCountMethod='any';

LocalSettings.d/base/cdn.php

@@ -0,0 +1,10 @@
+<?php
+
+$wgUseCdn = getenv('USE_CDN') === 'true' ? true : false;
+
+if ($wgUseCdn) {
+    $wgCdnServers = [ '10.217.0.0/16' ];
+    $wgInternalServer = str_replace('https://', 'http://', $wgServer);
+    $wgCdnMaxAge = 18000; // 5 hours (default)
+    $wgCdnMaxageLagged = 18000; // MediaWiki incorrectly detects lagged database due to Galera cluster architecture.
+}