[Backup core only] Do not backup image cache - First step

scripts/backup

@@ -13,14 +13,32 @@ source /usr/share/yunohost/helpers
 #=================================================
 ynh_print_info --message="Declaring files to be backed up..."
 
+#=================================================
+# APPLY BACKUP CORE ONLY POLICY
+#=================================================
+# Apply policy only if we are not in upgrade mode
+
+BACKUP_CORE_ONLY=${BACKUP_CORE_ONLY:-auto}
+if [ "$BACKUP_CORE_ONLY" == "auto" ] ; then
+    BACKUP_CORE_ONLY=$(ynh_app_setting_get --app="$app" --key="backup_core_only")
+    BACKUP_CORE_ONLY=${BACKUP_CORE_ONLY:-0}
+fi
+
 #=================================================
 # BACKUP THE APP MAIN DIR
 #=================================================
 
 # Clean cache files before backup (saved some disk space)
 ynh_secure_remove --file=$install_dir/var/cache/prod
 
-ynh_backup --src_path="$install_dir"
+if [ "$BACKUP_CORE_ONLY" ] ; then
+    ynh_print_warn --message="Backing up only the core... If you downloaded article images, they will not be saved."
+    mv "$install_dir/web/assets/images" "/tmp/$app/web/assets/images"
+    ynh_backup --src_path="$install_dir"
+    mv "/tmp/$app/web/assets/images" "$install_dir/web/assets/images"
+else
+    ynh_backup --src_path="$install_dir"
+fi
 
 #=================================================
 # BACKUP THE SYSTEM CONFIGURATION