[mod] backup script rewritten (inspired and adpated from example_ynh).

Currently neither backup nor restore are useful but are safe enough to
not break the upgrade script. That's what matters for now.

scripts/backup

@@ -1,9 +1,62 @@
 #!/bin/bash
 
-backup_dir="${1}/apps/vpnclient"
-mkdir -p "${backup_dir}/"
+#=================================================
+# GENERIC START
+#=================================================
+# IMPORT GENERIC HELPERS
+#=================================================
 
-sudo cp -a /etc/openvpn/keys/ "${backup_dir}/"
-sudo cp -a /etc/openvpn/client.conf.tpl "${backup_dir}/"
+if [ ! -e _common.sh ]; then
+	# Get the _common.sh file if it's not in the current directory
+	cp ../settings/scripts/_common.sh ./_common.sh
+	chmod a+rx _common.sh
+fi
+source _common.sh
+source /usr/share/yunohost/helpers
+
+#=================================================
+# MANAGE SCRIPT FAILURE
+#=================================================
+
+ynh_abort_if_errors # Stop script if an error is detected
+
+#=================================================
+# LOAD SETTINGS
+#=================================================
+
+app=$YNH_APP_INSTANCE_NAME
+
+final_path=$(ynh_app_setting_get $app final_path)
+domain=$(ynh_app_setting_get $app domain)
+
+#=================================================
+# STANDARD BACKUP STEPS
+#=================================================
+# BACKUP THE APP MAIN DIR
+#=================================================
+
+ynh_backup "$final_path"
+
+#=================================================
+# BACKUP THE NGINX CONFIGURATION
+#=================================================
+
+ynh_backup "/etc/nginx/conf.d/$domain.d/${app}.conf"
+
+#=================================================
+# BACKUP THE PHP-FPM CONFIGURATION
+#=================================================
+
+ynh_backup "/etc/php5/fpm/pool.d/$app.conf"
+
+#=================================================
+# SPECIFIC BACKUP
+#=================================================
+# BACKUP SYSTEMD
+#=================================================
+
+ynh_backup "/etc/systemd/system/ynh-$app.service" # XXX maybe hard-coding the full name would be better
+ynh_backup "/etc/systemd/system/ynh-$app-checker.service" # XXX maybe hard-coding the full name would be better
+ynh_backup "/etc/systemd/system/ynh-$app-checker.timer" # XXX maybe hard-coding the full name would be better
 
 exit 0