Add persistent mode (just set the variable : PERSISTENT=)

scripts/install_client.sh

@@ -63,6 +63,8 @@ ubuntu-drivers install ||:
 cp -r system /tmp
 cd /tmp/system
 
+test -v PERSISTENT && rm -rf etc/gdm3 usr/share/initramfs-tools
+
 # Overwrite with custom files from Git repository
 if test -v OVERWRITE; then
 	folder=$(echo "$OVERWRITE" | cut -d';' -f1)
@@ -94,6 +96,7 @@ cp --preserve=mode -RT . /
 cd $script_dir
 rm -rf /tmp/system
 
+if ! test -v PERSISTENT; then
 	sgdisk -n0:0:+32G "$disk"
 	sgdisk -N0 "$disk"
 	sgdisk -c3:01-tmp-home "$disk"
@@ -125,5 +128,6 @@ gpasswd -d student lpadmin
 	gpasswd -d student sambashare
 
 	cp /etc/shadow /etc/shadow-
+fi
 
 . clean.sh