Script to enable loop recording on motion / motioneye / motionEyeOs or any other Surveillance system

Motivation:

When setting up motionEyeOs on a raspberry pi zero recently, i noticed that motionEyeOs lacks a functionality called 'Loop Recoding', a common mechanism for surveillance systems that prevents the storage from running full by deleting the oldest recordings whenever free space gets scarce. There is a 'delete footage after X days' functionality, but since the amount of footage recorded within a specific time is depending on how frequent motion is detected, there is no guarantee that the storage will not run full even when using this setting. I know that there are open feature requests for adding loop recording on motioneyeos, but since this is not done yet, i wrote this little addon script that adds the Loop Recoding functionality to your motionEyeOs. Though motionEyeOs is not required to run this script and it could also be used for any other surveillance system.

Please feel free to contribute your ideas or improvements.

How it works

After installation, a script will check the free space of the filesystem each time a recording is saved. If the free space is under a certain threshold, it will start deleting files, beginning with the oldest one until the configured threshold is reached again.

Usage without motionEyeOs

The script itself does not contain any motion(Eye) specific code and can be used on all kinds of systems which are able to run python. Just execute the loop_delete.py periodically (via cron for example).

Usage:

usage: loop_delete.py [-h] --dir DIR --space MEGABYTES

To delete as many old files from DIR until MEGABYTES of space is available

Installation on MotionEyeOs

Once installed, the addon becomes a part of the configuration and therefore will be backed up and restored by motionEye's backup/restore functionality.

Login to your motionEye web interface as admin and enable SSH under 'Services', save and wait for the device to reboot. Then login to your device via SSH with your admin user and password which you normally use for logging in to the web interface:

Step 1: login via SSH

Linux:

ssh admin_username@ip_address_of_motioneyeos

Windows:

Use Putty to login to your motionEyeOs via ssh. HowTo's on how to use Putty can be found on the internet, like this for example.

Step 2: Install the Addon script

After being logged in successfully, a commandline terminal will open. Copy the following command into the terminal and hit Enter. This will install the addon.

curl https://raw.githubusercontent.com/DavHau/motioneye-loop-record/master/loop_delete.py > /data/etc/loop_delete.py && chmod +x /data/etc/loop_delete.py

Step 3: Enable the addon in the web iterface

• Use your browser to login to the web interface of your MotionEyeOs.
• Open the Settings and go to 'File Storage'.
• Turn on 'Run A Command'. A text field will appear to enter a command.
• Copy the following command into the text field, but replace '/data/output' in case you use a different root directory for your recodings.

/data/etc/loop_delete.py -d /data/output/ -s 500

This will always ensure that at least 500 MB will be kept free in /data/output/.

You can of course change the threshold of 500 to your needs.