A hive publishing its own status needs the same connect the controller
already has - mint an authelia token, present it at CONNECT for the
callout responder, let async-nats re-run the callback per attempt. Only
the use differs: the controller reads, a hive writes.
Copying it would put credential handling in two places, and a
token-refresh fix would then have to be found twice. That is the same
reasoning that already put hive-sock-client in its own crate rather than
in each daemon that speaks to a unix socket.
`from_env` takes a prefix rather than hardcoding SWARM_CONTROLLER_*: the
variables belong to the consuming unit, since a NixOS module sets them
alongside its other options. What is shared is the RULE - all four
together or none at all - not the spelling. The half-set case gains a
test, because it is the case the rule exists for and it previously had
none.
No jetstream/kv feature on the crate: it ends at a connected client, and
what a consumer does with it should be visible in that consumer's own
Cargo.toml.
Behaviour-preserving, and proven that way rather than by inspection: the
full behavioural gate (real nats-server, credential rotation, mutation)
is 20/0 unchanged, and the controller's own tests still pass.
Both from argus's review on the PR, both non-blocking, both real.
The HTTP client had no timeout, and it runs INSIDE the auth callback: a
token endpoint that accepts the connection and then never answers would
hang the callback and the connection attempt that invoked it, with no
retry and nothing in the log to say why. That is the same hang class the
status endpoint's connection-state check exists to prevent, one layer up.
Failing fast lets async-nats back off and try again, which it already
does well.
And the startup log said "connected to the swarm queue" at a point where
`retry_on_initial_connect` guarantees no connection has been established
yet - so the journal would read "connected", then 503 "not connected"
moments later, and a reader would rightly distrust the second line rather
than the first.
The controller connects to the swarm queue as its own client and serves
what each hive last said about itself at GET /api/hives/status.
THE QUEUE IS THE STORE. A hive publishes into the `hive-status` JetStream
KV bucket (history 1) and the controller reads it per request, keeping no
copy. A cache here would be a second answer to the same question, free to
disagree with the first, and the disagreement surfaces as a hive reading
healthy on a dashboard while the bucket says otherwise. Whichever side
arrives first creates the bucket; both want the same shape.
Rows come from the roster rather than from the bucket, so an empty bucket
renders as a swarm nobody has heard from instead of a healthy one, and
`never_reported` stays distinct from `stale` - went quiet is a fault,
never spoke is usually a deployment that has not happened. Freshness is
derived at read time and never stored as a flag, because a stored
`healthy` boolean goes stale silently the moment nothing arrives, which
is the failure this endpoint is designed against. The timestamp is the
NATS server's, applied when the value landed, so a publisher cannot make
itself look fresher than it is.
Authentication is per connection attempt, not per process. Authelia
issues `client_credentials` tokens that expire in 3599s, and auth happens
at CONNECT, so a long-lived connection is fine but a reconnect an hour
later needs a token minted an hour later. `with_auth_callback` is re-run
by async-nats for each attempt, which handles expiry by construction
rather than by a timer - the alternative fails in the way this subsystem
exists to prevent, with the controller still serving while its data
quietly stops updating.
Three failure shapes are deliberate:
- A half-set environment is fatal; an absent one is not. Silently
behaving like an unconfigured host is how every hive ends up reading
`never_reported` with nothing to point at.
- The endpoint answers 503 rather than an empty list when the store
cannot be read. "I cannot reach the store" and "every hive is silent"
are different answers, and rendering the second turns a local fault
into an apparent swarm-wide outage.
- `retry_on_initial_connect` makes the daemon and the queue bootable in
either order, and the status handler refuses when the client is not
Connected rather than issuing a request into it - a request made in
that window does not fail, it waits, so every poll would hang and
learn nothing. `Pending` is the state a never-connected client is in,
which is why the test is `!= Connected` and not `== Disconnected`.
The rendering rules are a pure function over a map, so the semantics are
tested against a table rather than against a running server. The KV read,
the credential rotation and the 503 paths are covered behaviourally
instead: a real NATS server with a rotating token endpoint, asserting
that the controller recovers only when the credential rotates, and
mutation-tested by holding the credential wrong for the same window.
