Conditionally define the default extension source

Since $type and $source are both class parameters, we can't
interpolate $type in the default definition for $source. Instead
redefine $source inside the resource if it's unchanged from the
resource default.

Also make the contents of /src/mediawiki/w require the vcsrepo
resource for it. Early creation of the directory causes vcsrepo to
fail to clone into it.

Change-Id: I9b447173d4966f03a195825047cf25afc1a4afd6

manifests/app.pp

@@ -12,12 +12,14 @@ class mediawiki::app ($revision = 'origin/REL1_27'){
     provider => git,
     source   => 'https://gerrit.wikimedia.org/r/p/mediawiki/vendor.git',
     revision => $revision,
+    require  => Vcsrepo['/srv/mediawiki/w'],
   }
   file { '/srv/mediawiki/w/cache':
     ensure  => directory,
     recurse => true,
     owner   => 'www-data',
     group   => 'www-data',
+    require => Vcsrepo['/srv/mediawiki/w'],
   }
 }
 

manifests/extension.pp

@@ -1,16 +1,25 @@
 define mediawiki::extension (
   $type     = 'extension',
   $ensure   = latest, # keep up to date
-  $source   = "https://gerrit.wikimedia.org/r/p/mediawiki/${type}s/${name}.git",
+  $source   = undef, # actual default conditionally applied below
   $revision = 'origin/REL1_27',
 ) {
   if $type != 'extension' and $type != 'skin' {
     fail( '$type must be extension or skin' )
   }
+  if $source == undef {
+    # Set our actual default for $source here since we can't interpolate $type
+    # in it for the resource parameter default
+    $src = "https://gerrit.wikimedia.org/r/p/mediawiki/${type}s/${name}.git"
+  } else {
+    $src = $source
+  }
+
   vcsrepo { "/srv/mediawiki/w/${type}s/${name}":
     ensure   => $ensure,
     provider => git,
-    source   => $source,
+    source   => $src,
     revision => $revision,
+    require  => Vcsrepo['/srv/mediawiki/w'],
   }
 }