add vlan inventory report

Netdisco/lib/App/Netdisco/DB/Result/DeviceVlan.pm

@@ -69,6 +69,17 @@ __PACKAGE__->has_many( port_vlans_native => 'App::Netdisco::DB::Result::Virtual:
     { cascade_copy => 0, cascade_update => 0, cascade_delete => 0 }
 );
 
+=head2 ports
+
+Link relationship to support C<ports>.
+
+=cut
+
+__PACKAGE__->has_many( ports => 'App::Netdisco::DB::Result::DevicePortVlan',
+    { 'foreign.ip' => 'self.ip', 'foreign.vlan' => 'self.vlan' },
+    { cascade_copy => 0, cascade_update => 0, cascade_delete => 0 }
+);
+
 =head2 tagging_ports
 
 Returns the set of Device Ports on which this VLAN is configured to be tagged.

Netdisco/lib/App/Netdisco/Web/Plugin/Report/VlanInventory.pm

@@ -0,0 +1,44 @@
+package App::Netdisco::Web::Plugin::Report::VlanInventory;
+
+use Dancer ':syntax';
+use Dancer::Plugin::DBIC;
+use Dancer::Plugin::Auth::Extensible;
+
+use App::Netdisco::Web::Plugin;
+
+register_report(
+    {   category     => 'VLAN',
+        tag          => 'vlaninventory',
+        label        => 'VLAN Inventory',
+        provides_csv => 1,
+    }
+);
+
+get '/ajax/content/report/vlaninventory' => require_login sub {
+    my $set = schema('netdisco')->resultset('DeviceVlan')->search(
+        { 'vlan.description' => { '!=', 'NULL' } },
+        {   join   => { 'ports' => 'vlan' },
+            select => [
+                'vlan.vlan',
+                'vlan.description',
+                { count => { distinct => 'ports.ip' } },
+                { count => 'ports.vlan' }
+            ],
+            as       => [qw/ vlan description dcount pcount /],
+            group_by => [qw/ vlan.vlan vlan.description /],
+        }
+    );
+    return unless $set->count;
+
+    if ( request->is_ajax ) {
+        template 'ajax/report/vlaninventory.tt', { results => $set, },
+            { layout => undef };
+    }
+    else {
+        header( 'Content-Type' => 'text/comma-separated-values' );
+        template 'ajax/report/vlaninventory_csv.tt', { results => $set, },
+            { layout => undef };
+    }
+};
+
+true;