Backup and Restore Feature in RPI - Design

Introduction

Backup and Restore is the feature developed in regard to WebUI.

The user can Backup the current user settings to the local PC and Restore the same to device when required.

Backup Settings:

• Allows the user to save the current settings
• Settings from database files are backed up
• The backup files are encrypted using the secure key inputted from the User
• Generates a tar file of the encrypted database files
• Saves the tar file to Local PC.

Restore Settings:

• Allows the user to select the backup file with required settings
• Extracts the tar file containing database files
• Decrypts the database files using valid secure key entered by user
• Loads backed up settings to device
• Device will be rebooted automatically to apply the settings.

Design Considerations

Backup and Restore functionalities are supported by a set of script files. Following are the mentioned script files:

   →   ConfPhp

   →  download_user_settings.php

   →   upload_user_settings1.php

   →   upload_user_settings2.php

   →   backup_user_settings.php

   →   backup_enc_key.php

   → ajax_at_saving_backup_key.php

These script files which are already present in the RDK build, will execute when the Backup and Restore buttons are clicked.

Backup Settings

Scripts backup_user_settings.php, download_user_settings.php  downloads the tar file containing database files.

The database files which contains the Current User settings are used for back up. A tar file is generated with these files together and stored in temporary folder /tmp/. The tar file from temporary folder is downloaded to the Local PC of User.

Restore Settings

Scripts upload_user_settings1.php, upload_user_settings2.php perform the Restore and Status update functions.

The files which are uploaded in WebUI are extracted to get the database files. The database files are saved to temporary folder /var/tmp/. The files are retrieved and replaced with the existing database files in RPi image.

Other Considerations (DAR)

It is required for the device to be rebooted once the Restore feature is executed successfully. This is because the settings which are updated to the database files when the backup file is uploaded, has to be applied, to be reflected in the WebUI.

During code development, two approaches were considered while designing the Restore feature.

• 1st approach: After successful Restore, the device automatically boots to apply new settings, using the reboot command executed immediately after printing the message "Need Reboot to Save restore configurations"  in the upload_user_settings2.php file.
•  2nd approach: After successful Restore, the device automatically boots to apply new settings, using the "setStr("Device.X_CISCO_COM_DeviceControl.RebootDevice","Device",true);"  command executed immediately after printing the message "Need Reboot to Save restore configurations"  in the upload_user_settings2.php file.

The latter approach has been implemented as it was found to be more preferable and acceptable as compared to the former. This is because the former approach led to direct reboot of device without allowing the success message to be printed on Web screen.

Architecture

Limitations

The downloaded file, backup.tar is the default name given to the backup file. Once downloaded to Local PC, this file has to be replaced with new backup.tar file. If the old file is not deleted, it may cause misbehavior in Restore feature execution. The old file can be either deleted or renamed to avoid duplicate file creation. Please Refer User manual for further details.

During Restore, the file to be uploaded has to be named to backup.tar by default.

Future Enhancements

Backup Feature

•      Naming convention for the backup.tar file with versions/time of file creation can be automated.

                Example: backup_2711191230.tar for files generated on 27/11/19 12:30PM.

Restore Feature

•      During file upload, selection of files with any name, can be made possible.

                Example: Wifi_settings.tar