[users] Add .conf entries for hostname settings

- Set hostname not-at-all, or via one of two mechanisms
 - Write /etc/hosts or not

src/modules/users/UsersViewStep.cpp

@@ -141,8 +141,7 @@ UsersViewStep::onLeave()
     j = new SetPasswordJob( "root", m_widget->getRootPassword() );
     m_jobs.append( Calamares::job_ptr( j ) );
 
-    j = new SetHostNameJob( m_widget->getHostname(),
+    j = new SetHostNameJob( m_widget->getHostname(), m_actions );
-                            SetHostNameJob::Action::EtcHostname | SetHostNameJob::Action::EtcHosts );
     m_jobs.append( Calamares::job_ptr( j ) );
 }
 
@@ -206,4 +205,21 @@ UsersViewStep::setConfigurationMap( const QVariantMap& configurationMap )
     // Now it might be explicitly set to empty, which is ok
 
     Calamares::JobQueue::instance()->globalStorage()->insert( "userShell", shell );
+
+    using Action = SetHostNameJob::Action;
+
+    QString hostnameActionString = CalamaresUtils::getString( configurationMap, "setHostname" );
+    if ( hostnameActionString.isEmpty() )
+    {
+        hostnameActionString = QStringLiteral( "EtcFile" );
+    }
+    bool ok = false;
+    auto hostnameAction = hostnameActions().find( hostnameActionString, ok );
+    if ( !ok )
+    {
+        hostnameAction = Action::EtcHostname;
+    }
+
+    Action hostsfileAction = getBool( configurationMap, "writeHostsFile", true ) ? Action::EtcHosts : Action::None;
+    m_actions = hostsfileAction | hostnameAction;
 }

src/modules/users/users.conf

@@ -122,3 +122,17 @@ allowWeakPasswordsDefault: false
 #  - set, non-empty, use that path as shell. No validation is done
 #    that the shell actually exists or is executable.
 # userShell: /bin/bash
+
+# Hostname setting
+#
+# The user can enter a hostname; this is configured into the system
+# in some way; pick one of:
+#   - *None*, to not set the hostname at all
+#   - *EtcFile*, to write to `/etc/hostname` directly
+#   - *Hostnamed*, to use systemd hostnamed(1) over DBus
+# The default is *EtcFile*.
+setHostname: EtcFile
+
+# Should /etc/hosts be written with a hostname for this machine
+# (also adds localhost and some ipv6 standard entries).
+writeHostsFile: true