Ensure mrccomm is fully up before loading HAL

[ThadHouse]

Some of the things we do in mrccomm depend on it being up and reponsive before the robot process starts. We should add a way to enforce this, likely with an mrccomm key that is set right at the end of ready state.

[rzblue]

This can also be soft-enforced at startup by systemd. We'd still want a check in the HAL but making the robot program depend on mrccomm in systemd will prevent it crashlooping at startup.

[ThadHouse]

Not exactly. mrccomm can still crashloop if the heartbeat isn't fully up yet. But the robot process can't connect until after this crash looping has stopped.

In the latest alpha, it does properly depend on mrccomm.

[rzblue]

I meant the robot program crashlooping.
MrcComm crashing would be fine and the dependency would still be handled properly by systemd if it were a notify type service and it only notified as ready after it was all set up

[ThadHouse]

If there’s an easy way to set up systemd to do that, that’s probably a good idea.