implemented plugin dependency handling:

* installing a plugin into a vendor-OS is now only possible when required 
  plugins are already installed
* removing a plugin from a vendor-OS is now only possible when now plugins
  that depend on this one are still installed
* the config-demuxer will check the plugin depedency hierarchy and bail if 
  any plugin is missing
* when several plugins are being auto-installed (e.g. when copying all
  plugins from the '<<<default>>>' vendor-OS) the order of the plugins is
  adjusted to comply with the dependency hierarchy
* declared one single dependency: vmchooser depends on vmware (please shout
  if that is incorrect)

git-svn-id: http://svn.openslx.org/svn/openslx/openslx/trunk@1936 95ad53e4-c205-0410-b2fa-d234c58c8868

2 files changed, 129 insertions, 0 deletions

diff --git a/os-plugins/OpenSLX/OSPlugin/Base.pm b/os-plugins/OpenSLX/OSPlugin/Base.pm
index 2b6075f5..734a74f5 100644
--- a/os-plugins/OpenSLX/OSPlugin/Base.pm
+++ b/os-plugins/OpenSLX/OSPlugin/Base.pm
@@ -61,6 +61,7 @@ implementation, please drop a mail to: ot@openslx.com, or join the IRC-channel
 =cut
 
 use OpenSLX::Basics;
+use OpenSLX::OSPlugin::Roster;
 
 =head1 PLUGIN API
 
@@ -122,6 +123,13 @@ a higher precedence).
 Valid values range from 0-99. If your plugin does not have any requirements
 in this context, just specify the default value '50'.
 
+=item B<required>
+
+Specifies the list of plugins that are required by this plugin.
+
+Before any plugin can be installed, all other plugins that are required by it
+must have been installed.
+
 =back
     
 =cut
@@ -209,6 +217,23 @@ sub checkStage3AttrValues
     return;
 }
 
+=item dependsOnPlugin()
+
+=cut
+
+sub dependsOnPlugin
+{
+    my $self      = shift;
+    my $otherName = shift;
+    
+    if (!defined $self->{dependsOn}) {
+        my @dependsOn = $self->_determineAllPluginsWeDependOn();
+        $self->{dependsOn} = \@dependsOn;
+    }
+    
+    return grep { $_ eq $otherName } @{$self->{dependsOn}};
+}
+
 =back
 
 =head2 Vendor-OS Interface
@@ -439,6 +464,28 @@ sub setupPluginInInitramfs
     return 1;
 }
 
+sub _determineAllPluginsWeDependOn
+{
+    my $self = shift;
+    my $seen = shift || {};
+
+    return if $seen->{$self->{name}};
+    $seen->{$self->{name}} = 1;
+
+    my %dependsOn;
+    if ($self->getInfo()->{required}) {
+        @dependsOn{@{$self->getInfo()->{required}}} = ();
+    }
+
+    foreach my $depName (keys %dependsOn) {
+        my $depPlugin = OpenSLX::OSPlugin::Roster->getPlugin($depName);
+        my @subDeps = $depPlugin->_determineAllPluginsWeDependOn($seen);
+        @dependsOn{@subDeps} = ();
+    }
+
+    return keys %dependsOn;
+}
+
 =back
 
 1;
diff --git a/os-plugins/OpenSLX/OSPlugin/Engine.pm b/os-plugins/OpenSLX/OSPlugin/Engine.pm
index 3f73a97a..ae76c9e0 100644
--- a/os-plugins/OpenSLX/OSPlugin/Engine.pm
+++ b/os-plugins/OpenSLX/OSPlugin/Engine.pm
@@ -23,6 +23,7 @@ use File::Path;
 use Storable;
 
 use OpenSLX::Basics;
+use OpenSLX::OSPlugin::Roster;
 use OpenSLX::OSSetup::Engine;
 use OpenSLX::ScopedResource;
 use OpenSLX::Utils;
@@ -146,6 +147,8 @@ Invokes the plugin's installer method while chrooted into that vendor-OS.
 sub installPlugin
 {
     my $self = shift;
+    
+    $self->_checkIfRequiredPluginsAreInstalled();
 
     if ($self->{'vendor-os-name'} ne '<<<default>>>') {
 
@@ -209,6 +212,8 @@ sub removePlugin
 {
     my $self = shift;
 
+    $self->_checkIfPluginIsRequiredByOthers();
+
     if ($self->{'vendor-os-name'} ne '<<<default>>>') {
 
         mkpath([ $self->{'plugin-repo-path'}, $self->{'plugin-temp-path'} ]);
@@ -638,6 +643,83 @@ sub _addInstalledPluginToDB
     return 1;
 }
 
+sub _checkIfRequiredPluginsAreInstalled
+{
+    my $self = shift;
+    
+    my $requiredPlugins = $self->{plugin}->getInfo()->{required} || [];
+    return 1 if !@$requiredPlugins;
+
+    my $openslxDB = instantiateClass("OpenSLX::ConfigDB");
+    $openslxDB->connect();
+    my $vendorOS = $openslxDB->fetchVendorOSByFilter( { 
+        name => $self->{'vendor-os-name'},
+    } );
+    if (!$vendorOS) {
+        die _tr(
+            'unable to find vendor-OS "%s" in DB!', $self->{'vendor-os-name'}
+        );
+    }
+    my @installedPlugins = $openslxDB->fetchInstalledPlugins($vendorOS->{id});
+    $openslxDB->disconnect();
+    
+    my @missingPlugins 
+        =   grep {
+                my $required = $_;
+                ! grep { $_->{plugin_name} eq $required } @installedPlugins;
+            }
+            @$requiredPlugins;
+
+    if (@missingPlugins) {
+        die _tr(
+            'the plugin "%s" requires the following plugins to be installed first: "%s"!', 
+            $self->{'plugin-name'}, join(',', @missingPlugins)
+        );
+    }        
+    
+    return 1;
+}
+
+sub _checkIfPluginIsRequiredByOthers
+{
+    my $self = shift;
+    
+    my $openslxDB = instantiateClass("OpenSLX::ConfigDB");
+    $openslxDB->connect();
+    my $vendorOS = $openslxDB->fetchVendorOSByFilter( { 
+        name => $self->{'vendor-os-name'},
+    } );
+    if (!$vendorOS) {
+        die _tr(
+            'unable to find vendor-OS "%s" in DB!', $self->{'vendor-os-name'}
+        );
+    }
+    my @installedPlugins = $openslxDB->fetchInstalledPlugins($vendorOS->{id});
+    $openslxDB->disconnect();
+    
+    my @lockingPlugins
+        =   grep {
+                my $installed 
+                    = OpenSLX::OSPlugin::Roster->getPlugin($_->{plugin_name});
+                my $requiredByInstalled 
+                    = $installed
+                        ? ($installed->getInfo()->{required} || [])
+                        : [];
+                grep { $_ eq $self->{'plugin-name'} } @$requiredByInstalled;
+            }
+            @installedPlugins;
+
+    if (@lockingPlugins) {
+        die _tr(
+            'the plugin "%s" is required by the following plugins: "%s"!', 
+            $self->{'plugin-name'}, 
+            join(',', map { $_->{plugin_name} } @lockingPlugins)
+        );
+    }        
+    
+    return 1;
+}
+
 sub _fetchInstalledPluginAttrs
 {
     my $self = shift;