testing: Fix systemctl wrapper and adapt enabling services on winnetou

The wrapper called the command twice for any unit but "strongswan" and
it didn't return the correct exit code.  This was noticed when an
if-updown script tried to check if systemd-resolved is active and always
succeeded, which caused failing attempts to configure it.

But now that the return code is correct, trying to enable bind9 won't
fail silently anymore if the unit doesn't exist (similar on older systems
for named), so this is adapted.

testing/hosts/default/usr/local/bin/systemctl

@@ -8,7 +8,7 @@ ORIG=/bin/systemctl
 CONF=/lib/systemd/system/strongswan.service
 
 if [[ "$2" != "strongswan" ]]; then
-	$ORIG "$@"
+	exec $ORIG "$@"
 fi
 
 if [[ "$1" == "start" && -n $LEAK_DETECTIVE_LOG ]]; then
@@ -16,7 +16,10 @@ if [[ "$1" == "start" && -n $LEAK_DETECTIVE_LOG ]]; then
 fi
 
 $ORIG "$@"
+STATUS=$?
 
 if [[ "$1" == "stop" ]]; then
 	sed -i '/LEAK_DETECTIVE_LOG/d' $CONF 2>/dev/null
 fi
+
+exit $STATUS

testing/scripts/build-guestimages

@@ -76,10 +76,19 @@ do
 		execute_chroot "dnssec-signzone -K /etc/bind -o org. /etc/bind/db.org" 0
 		execute_chroot "dnssec-signzone -K /etc/bind -o . /etc/bind/db.root" 0
 
-		# on bullseye, enabling via bind9 doesn't work, while disabling does, so
+		# on bullseye and newer, enabling via bind9 doesn't work, while
-		# use named there. on the other hand, older releases don't have named
+		# disabling does, so use named here. on the other hand, older releases
-		# service files (systemctl returns 0 even if files are not found)
+		# like buster don't have named service files
-		for service in apache2 slapd bind9 named
+		SERVICES="apache2 slapd"
+		case "$BASEIMGSUITE" in
+		buster)
+			SERVICES="$SERVICES bind9"
+			;;
+		*)
+			SERVICES="$SERVICES named"
+			;;
+		esac
+		for service in $SERVICES
 		do
 			execute_chroot "systemctl enable $service" 0
 		done