Set group ownership of unix socket

[bryfry]

Is your feature request related to a problem? Please describe.
I have a command that I want to run as root wrapped up by ttyd but I'd like nginx user (www-data) to be able to access the unix socket created by ttyd.

Describe the solution you'd like
This would be made possible by allowing the permissions (owner:group) for the newly created ttyd socket file.

Describe alternatives you've considered
I've worked around this issue by modifying the permissions of the socket after it comes online.

Additional context
I'm a huge fan of the unix socket interface. This was only a minor inconvenience in an otherwise awesome experience getting ttyd setup to accomplish my project needs.

[tsl0922]

The underlying websocket feature (and unix socket) is based on libwebsockets, so if libwebsocket support it (didn't check yet), I'm OK to add it to ttyd.

[cRoCx]

I had the same or similar issue and solved it by having ttyd executed as user exampleuser and group www-data through a systemd service.
An example of this service can be found in the wiki here.
Instead of Group=root you could use Group=www-data.
When ttyd is called with -i /tmp/ttyd.sock the socket file with have rw permissions for user exampleuser and group www-data.