Services are the only component group that binds a port during parsing
(ParseService calls listener.Init). The generic registerGroup "parse-all-
then-swap" sequence bound every new listener while the old services were
still listening, causing EADDRINUSE on SIGHUP reload — a regression from
82e7e50.
Close and unregister all old services first (unregisterAll relies on
registry.Unregister closing io.Closer values, which frees each service's
port), then parse, bind, and register the new ones. This restores the
pre-82e7e50 close-old-before-bind ordering for the services group.
- Add 808-line loader_test.go covering registerGroup, register, and Load
- Add package and exported symbol doc comments to loader.go
- Fix fmt.Errorf(resp.Status) → errors.New(resp.Status) in sd/plugin/http.go
(resp.Status is a plain string, not a format string)
ginuerzh