Add support for non-critical groups in netinstall.

Package groups are divided into critical and non-critical
depending on whether we want all Calamares to fail if installing
a package in the group fails, or we are okay with just logging a
warning.

The distinction is configured in the YAML file listing the package
groups. By default, all groups are critical, to keep supporting
the previous behaviour.

src/modules/netinstall/NetInstallPage.cpp

@@ -85,6 +85,9 @@ void NetInstallPage::readGroups( const QByteArray& yamlData )
         if ( groupDefinition["hidden"] )
             m_groups[name].hidden = yamlToVariant( groupDefinition["hidden"] ).toBool();
 
+        if ( groupDefinition["critical"] )
+            m_groups[name].critical = yamlToVariant( groupDefinition["critical"] ).toBool();
+
         m_groupOrder.append( name );
     }
 }
@@ -124,25 +127,25 @@ NetInstallPage::dataIsHere( QNetworkReply* reply )
     emit checkReady( isReady() );
 }
 
-QStringList NetInstallPage::selectedPackages() const
+QList<Group> NetInstallPage::selectedGroups() const
 {
-    QStringList selectedPackages;
+    QList<Group> selectedGroups;
 
-    // Add all the packages for groups that are toggled in the view.
+    // Add all the groups that are toggled in the view.
     for ( auto it = m_groupWidgets.constBegin(); it != m_groupWidgets.constEnd(); it++ )
     {
         if ( it.value()->isToggled() )
-            selectedPackages += m_groups[it.key()].packages;
+            selectedGroups += m_groups[it.key()];
     }
 
-    // Add all the packages for groups that are hidden but selected.
+    // Add all groups that are hidden but selected.
     for ( const Group& group : m_groups.values() )
     {
         if ( group.hidden && group.selected )
-            selectedPackages += group.packages;
+            selectedGroups += group;
     }
 
-    return selectedPackages;
+    return selectedGroups;
 }
 
 void NetInstallPage::loadGroupList()

src/modules/netinstall/NetInstallPage.h

@@ -34,29 +34,30 @@ namespace Ui
 class Page_NetInst;
 }
 
+// Representation of a package group.
+struct Group
+{
+    Group()
+        : Group( "","",false, false, true ) { }
+    Group( QString name, QString description, bool selected, bool hidden, bool critical )
+        : name( name ), description( description ), selected( selected ), hidden( hidden ), critical( critical ) { }
+    Group( QString name, QString description )
+        : Group( name, description, false, false, true ) { }
+
+    QString name;
+    QString description;
+    QStringList packages;
+
+    // See README.md for a description of these fields.
+    bool selected = false;
+    bool hidden = false;
+    bool critical = true;
+};
+
 class NetInstallPage : public QWidget
 {
     Q_OBJECT
 
-    // Internal representation of a package group.
-    struct Group
-    {
-        Group()
-            : Group( "","",false, false ) { }
-        Group( QString name, QString description, bool selected, bool hidden )
-            : name( name ), description( description ), selected( selected ), hidden( hidden ) { }
-        Group( QString name, QString description )
-            : Group( name, description, false, false ) { }
-
-        QString name;
-        QString description;
-        QStringList packages;
-
-        // See README.md for a description of these two fields.
-        bool selected = false;
-        bool hidden = false;
-    };
-
 public:
     NetInstallPage( QWidget* parent = nullptr );
 
@@ -69,10 +70,9 @@ public:
     // in the global storage. This should be called before displaying the page.
     void loadGroupList();
 
-    // Returns the list of packages belonging to groups that are
-    // selected in the view in this given moment. No data is cached here, so
-    // this function does not have constant time.
-    QStringList selectedPackages() const;
+    // Return a list of groups currently selected. No data is cached here, so
+    // this function does not run in constant time.
+    QList<Group> selectedGroups() const;
 
 public slots:
     void dataIsHere( QNetworkReply* );

src/modules/netinstall/NetInstallViewStep.cpp

@@ -125,12 +125,31 @@ NetInstallViewStep::onLeave()
     cDebug() << "Leaving netinstall, adding packages to be installed"
              << "to global storage";
 
-    if ( !m_widget->selectedPackages().empty() )
+    const QList<Group>& selectedGroups = m_widget->selectedGroups();
+
+    if ( !selectedGroups.empty() )
     {
         QMap<QString, QVariant> packagesWithOperation;
-        // Gets all packages selected in the page; includes groups that are
-        // selected by default but not displayed.
-        packagesWithOperation.insert( "install", m_widget->selectedPackages() );
+        QStringList packages, critical_packages;
+
+        // We have two types of groups: "critical" (failing to install any of
+        // the packages makes Calamares fail) and "non critical" (we only log
+        // an error if the installation fails). We distinguish them here and select
+        // the correct package operation.
+        for (const Group& group : selectedGroups) {
+            if (group.critical) {
+                critical_packages += group.packages;
+            } else {
+                packages += group.packages;
+            }
+        }
+
+        if (!critical_packages.empty()) {
+            packagesWithOperation.insert( "install", critical_packages );
+        }
+        if (!packages.empty()) {
+            packagesWithOperation.insert( "try_install", packages);
+        }
 
         Calamares::GlobalStorage* gs = Calamares::JobQueue::instance()->globalStorage();
         gs->insert( "packageOperations", QVariant( packagesWithOperation ) );

src/modules/netinstall/README.md

@@ -27,8 +27,16 @@ The URL must point to a YAML file. Here is a short example of how the YAML file
 
 The file is composed of a list of entry, each describing one group. The keys *name*, *description* and *packages* are required.
 
-Two more keys are supported, *hidden* (if true, do not show the group on the page) and *selected* (if true, display the group as selected). Both default to false if not present.
-If both keys are set to true for the same group, you are basically creating a "default" group of packages which will always be installed in the user's system.
+Three more keys are supported:
+
+      - hidden: if true, do not show the group on the page. Defaults to false.
+      - selected: if true, display the group as selected. Defaults to false.
+      - critical: if true, make the installation process fail if installing
+        any of the packages in the group fails. Otherwise, just log a warning.
+        Defaults to true.
+
+If you set both *hidden* and *selected* for a group, you are basically creating a "default" group of packages
+which will always be installed in the user's system.
 
 ## Configuration of the module
 Here is the set of instructions to have the module work in your Calamares. As of July 2016, this has been successfully