Tailnet is an unofficial GUI wrapper around the Tailscale CLI.
A "Tailnet" is "The set of machines in a Tailscale network is referred to as a tailnet. Each machine in the tailnet is considered a node and is assigned a unique Tailscale IP address by the coordination server. Nodes can directly communicate with one another unless the traffic is restricted by the tailnet’s access control lists (ACLs)".
Source: Tailscale's glossary
Tailnet is an unofficial GUI wrapper around the Tailscale CLI client, particularly for use on Elementary OS, as no official Linux GUI client exists. It provides a dock icon and a fairly comprehensive UI with support for configuring Tailscale's features.
Tailnet interfaces with the Tailscale daemon, tailscaled, to perform many of its operations. In order for this to work, the daemon must have been configured with the current user as the "operator". To do this, run sudo tailscale set --operator=$USER from the command-line at least once manually.
Yes, the flatpak file exists and can be made locally.
The problem statement is that the command tailscale X cannot be run from within the container (with the operator set to $USER).
I am assuming the tailscale binary will need to be included within the Flatpak. I haven't looked into it beyond that.
This application started a way to learn more about Vala and Elementary OS' application developer docs.
Ater searching what is out there already, I found Trayscale. A big thank you and mention for the general concept and pane layout idea, but none of the source code (I don't know Go).
This application takes it's design style from the official Tailscale iOS application and Elementary's Granite library.