Add StateDisabled for operator-initiated disable, keeping StateRemoved
for backends that disappear during a config reload. Previously both
used StateRemoved, which was confusing: "removed" implies the backend
no longer exists in config, but a disabled backend is still present
and can be re-enabled on the fly.
- health: add StateDisabled with String() "disabled", Disable() method
with probe code "disabled". Record() rejects probes in all three
inactive states (paused, disabled, removed).
- checker: DisableBackend calls backend.Disable() instead of Remove().
- docs: healthchecks.md rewritten for pause (goroutine cancelled, not
just results discarded), and separate disabled/removed state rows.
user-guide.md updated to match.
- Makefile: add fixstyle target (gofmt -w .).
Prometheus metrics (internal/metrics/, cmd/maglevd/)
- New --metrics-addr flag (default :9091, env MAGLEV_METRICS_ADDR)
serving /metrics via promhttp.
- Gauge metrics scraped on demand via a custom prometheus.Collector:
maglev_backend_state, maglev_backend_health, maglev_backend_enabled,
maglev_frontend_pool_backend_weight.
- Inline counter/histogram metrics updated per probe:
maglev_probe_total (by backend, type, result, code),
maglev_probe_duration_seconds (by backend, type),
maglev_backend_transitions_total (by backend, from, to).
- StateSource interface in metrics package breaks the import cycle
with checker; checker.Checker satisfies it via GetBackendInfo.
Integration tests
- Run maglevd inside a containerlab node (debian:trixie-slim with
build/ bind-mounted) instead of on the host. Eliminates port
collisions with any host maglevd.
- maglevc commands run via docker exec into the maglevd container.
- Add 6 Prometheus test cases: endpoint reachable, all backends
report state=up, probe counters non-zero, duration histogram
populated, pool weights correct, transition counters present.
