I'm running the TP Link Omada Software Controller (v5) in an LXC in order to administer the Omada devices (wireless APs) on my network.

The instructions on TP Link's website can generally be followed to install the controller although it should be noted that I used Ubuntu 20.04 in order to provide the easiest path forward. This version supports Java 8 out of the box and makes it easy to install MongoDB 4.4 using the instructions given. More recent releases could be made to work but this was the simplest path forward for me.

After installing the controller and setting up the firewall/reverse proxy as usual in order to access it, follow the prompts in the web interface to perform basic setup. Then, go to Preferences from the Global View (under the overflow menu in the top right) and open the Server Settings page. Enable the SMTP server and set smtp.gmail.com in the SMTP field. SSL and Authentication should also be enabled with 465 for the Port.

The Username and Sender Address should both be the email address of the Gmail account used to send the email and the Password can be an app password generated through the Gmail account specifically for the Omada controller (without spaces). Send a test email and save once this works.

To update, simply download the latest .deb package from the TP-Link Omada website on the machine running the Omada controller. This can potentially be done through the GUI by selecting Download in response to the update available message. If not, right click on the Download button on the website to copy the URL and then use wget to download it on the server (for example, wget <deb_url>). Then, run dpkg -i <deb_file> to install it over the old version.