[Siderolink] Increase availability by having Talos fallback to HTTP2 when UDP does not work

[gravufo]

Feature Request

Talos could benefit from a fallback mechanism in Siderolink where it initially tries connecting in UDP and if that doesn't work, it falls back to TCP.

Description

If the network in which Talos will run is not owned by the person deploying the machine, it can happen that the outgoing Siderolink UDP port is blocked.
Currently, it's possible to generate a Talos image that forces it to use HTTP2, but it has to be done in advance, which is not always possible.
Having a try/fail/fallback mechanism would be helpful and remove the need to know the destination network conditions in advance.

[smira]

There is no change required on Talos side. SideroLink connection mode (UDP/HTTP) is controlled by the management API of SideroLink, the kernel arg is a hint. Ultimately SideroLink server controls the mode, not Talos.

[gravufo]

Opened an issue in the omni repo instead: siderolabs/omni#2202