Add support for UDP

[dfeyer]

Hi, thanks a lots for this project, love it.

Do you think it's possible to add UDP check ? I have a few Wireguard VPN to monitor, and it will be a pleasure to use Vigil

[valeriansaliou]

Hello! I've already considered that, but due to the datagram stateless nature of UDP, it's really hard to probe into an UDP socket in a generic way. We'd need Vigil to implement UDP-based protocols such as DNS, Wireguard, etc. to probe into specific UDP based protocols, which'd be too complex since a lot of people will be requesting a lot of different UDP-based protocols over time (eg. having a dns:// probe).

To circumvent this issue, if Wireguard lets you open a TCP port on the side, it could let you monitor your Wireguard setup via TCP, even if you're not using TCP in practice.