Issue 3190 - Ensure /var/cache/$cms_repository being present and writable

modules/web/manifests/server.pp

 class web::server(
     $vhost,
     $repository,
     $certificate = hiera('web::server::certificate', 'undef'),
     $private_key = hiera('web::server::private_key', 'undef'),
     $is_default = false,
     $aliases = undef,
     $custom_config = undef,
     $multiplexer_locations = undef,
     $geoip = false,
 ) {
 
+  # Ensure there is at least one character in the respective strings;
+  # see https://codereview.adblockplus.org/29329028/#msg3
+  validate_re($vhost, '.+')
+  validate_re($repository, '.+')
+
   File {
     owner  => 'root',
     group  => 'root',
     mode   => 0644,
   }
 
   Cron {
     environment => ['MAILTO=admins@adblockplus.org', 'PYTHONPATH=/opt/cms:/opt/sitescripts'],
   }
 
@@ skipping 64 matching lines @@
     user => www,
     timeout => 0,
     onlyif => "test ! -d /home/www/${repository}",
   }
 
   file {'/var/www':
     ensure => directory,
     mode => 755,
   }
 
-  file {"/var/www/${vhost}":
+  file {[
+    "/var/cache/${repository}",
+    "/var/www/${vhost}",
+  ]:
     ensure => directory,
     owner => www,
     mode => 755,
   }
 
   cron {'update_cms':
     ensure => present,
     command => "hg pull -q -u -R /opt/cms",
     minute  => '5-55/10',
   }
 
   cron {'update_repo':
     ensure => present,
     command => "hg pull -q -R /home/www/${repository} && python -m cms.bin.generate_static_pages /home/www/${repository} /var/www/${vhost}",
     user => www,
     minute  => '*/10',
   }
 }