Bind the app port deliberately and document the proxy deployment (closes #268) (closes #226)

internal/server/server.go

@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"os"
 	"os/signal"
+	"sync/atomic"
 	"syscall"
 	"time"
 
@@ -88,8 +89,15 @@ type ServerParams struct {
 // Server is the main HTTP server that wires up routes and manages
 // graceful shutdown.
 type Server struct {
-	startupTime   time.Time
-	sentryEnabled bool
+	startupTime time.Time
+
+	// sentryEnabled is written by the serving goroutine, in
+	// enableSentry, and read by the fx stop hook in cleanShutdown.
+	// Nothing orders those two: the OnStart hook returns as soon as
+	// the goroutine is spawned, so a stop can be running while
+	// enableSentry is still deciding. It is atomic to supply the
+	// edge the goroutines do not.
+	sentryEnabled atomic.Bool
 	log           *slog.Logger
 	cancelFunc    context.CancelFunc
 	httpServer    *http.Server
@@ -107,6 +115,7 @@ func New(lc fx.Lifecycle, params ServerParams) (*Server, error) {
 	s.mw = params.Middleware
 	s.h = params.Handlers
 	s.log = params.Logger.Get()
+	s.httpServer = s.newHTTPServer()
 
 	lc.Append(fx.Hook{
 		OnStart: func(_ context.Context) error {
@@ -142,7 +151,7 @@ func (s *Server) MaintenanceMode() bool {
 }
 
 func (s *Server) enableSentry() {
-	s.sentryEnabled = false
+	s.sentryEnabled.Store(false)
 
 	if s.params.Config.SentryDSN == "" {
 		return
@@ -163,7 +172,7 @@ func (s *Server) enableSentry() {
 	}
 
 	s.log.Info("sentry error reporting activated")
-	s.sentryEnabled = true
+	s.sentryEnabled.Store(true)
 }
 
 // serve installs the signal watcher, starts the listener and blocks
@@ -242,7 +251,7 @@ func (s *Server) cleanShutdown(ctx context.Context) {
 
 	s.cleanupForExit()
 
-	if s.sentryEnabled {
+	if s.sentryEnabled.Load() {
 		s.flushSentry(ctx)
 	}
 }