Determine node health at start completion instead of unconditionally
reaching Running. Zero transports up is now Failed (fatal): start()
tears down cleanly and returns an error, and the daemon exits. Any
configured optional child that failed to start - a transport beyond the
first, Nostr, mDNS, TUN, DNS, or a worker pool - leaves the node
Degraded but serving, with an operator warning naming what failed. All
configured children up is Full. A child the node was never asked to run
does not count against health.
The published NodeState gains Degraded and Failed variants, both visible
via control queries; Degraded is operational, Failed is not. The
lifecycle FSM gains the health states plus the PublishState action that
drives them - a health fork cannot be a single direct state write, which
is why the earlier commits deferred it to here.
Runtime child-exit health re-evaluation (a running child dying) is a
separate liveness-monitoring mechanism left for a follow-up; this commit
is start-time health only.
Add an operator-visible Draining phase on daemon shutdown. On the
shutdown signal the node broadcasts Disconnect to all peers, then keeps
serving for a bounded window - up to node.drain_timeout_secs (default 2s),
exiting early once all peers are gone - before tearing down. This lets
in-flight traffic settle and peers observe the disconnect before the
transports close, rather than the previous immediate teardown.
The lifecycle FSM gains a Draining state plus Drain/DrainDeadlineElapsed
events; the run loop observes the shutdown signal and transitions to
draining in place - one continuous loop, so the channel receivers are
never destructively cancelled. The published NodeState gains a Draining
variant, visible via control queries during the window. The immediate
stop() path used by tests and non-daemon callers is unchanged: it still
tears down immediately with no drain wait.
The reconciler-gate actions the drain emits are no-ops until the peering
reconciler lands and consumes them.
Introduce a sans-IO lifecycle supervisor: a synchronous step(event) ->
[action] state machine (SupervisorFsm) that authors the substrate-child
spawn and teardown order, plus an owner struct (Supervisor) holding the
substrate runtime fields and embedding the FSM. The substrate-lifecycle
fields leave Node's flat list into the owner - state, packet_tx, the TUN
reader/writer handles + shutdown fd + channels, the DNS task + identity
channel, the Nostr/LAN rendezvous drivers, and the encrypt/decrypt worker
pools; the dataplane keeps packet_rx.
start()/stop() become the driver executing the FSM's SpawnChild/StopChild
actions: same children, same order, same warn/debug-and-continue on
optional failures, same logs, same NodeState transitions. Behavior- and
wire-neutral. The only determinism change is that transports now tear
down in ascending-id order, previously nondeterministic HashMap iteration.
The bounded Draining phase and the Running{Full|Degraded} health split
land as separate follow-on commits.
Johnathan Corgan