Node health check #197
Description
The Problem
Currently, it's hard for users to know when their Hyperdrive installation is configured correctly and ready to operate effectively (i.e. attest/propose/etc with an Ethereum validator). For example, even if they read and follow the docs, sometimes users forget or misconfigure a setting necessary for their personal situation that HD can't help with like forwarding ports on their router.
In some scenarios, users nodes appear fine and they are able to create a validator but can't attest.
The Proposal
To assist users to understand if a node is ready, Hyperdrive and its modules should perform a health check on a regular basis and after any configuration change. Hyperdrive and its modules should ensure this health check is successful before starting to provide service for the first time (to avoid potentially accruing penalties for failing to perform effectively). For example, the health check functionality for hyperdrive-ethereum should ensure there is a reasonable number of connected peers, the machine is discoverable by an external server on appropriate ports, etc before a validator is started for the first time.
Health check results should be reported to nodeset.io to assist NodeSet with support and network monitoring. Note this likely would be implemented via a more general telemetry mechanism, which would mean #196 is a dependency.