add server heartbeat

bootstrap/service/fsd.go

@@ -4,12 +4,15 @@ import (
 	"context"
 	"errors"
 	"github.com/renorris/openfsd/client"
+	"github.com/renorris/openfsd/postoffice"
+	"github.com/renorris/openfsd/protocol"
 	"github.com/renorris/openfsd/servercontext"
 	"log"
 	"net"
 	"os"
 	"slices"
 	"sync"
+	"time"
 )
 
 type FSDService struct{}
@@ -39,7 +42,6 @@ func (s *FSDService) Start(ctx context.Context, doneErr chan<- error) (err error
 
 func (s *FSDService) boot(ctx context.Context, listener *net.TCPListener) error {
 	defer listener.Close()
-
 	defer log.Println("FSD server shutting down...")
 
 	incomingConns := make(chan *net.TCPConn)
@@ -48,6 +50,10 @@ func (s *FSDService) boot(ctx context.Context, listener *net.TCPListener) error
 	// Track each client connection in a wait group
 	waitGroup := sync.WaitGroup{}
 
+	// Start heartbeat worker
+	waitGroup.Add(1)
+	go s.heartbeatWorker(ctx, &waitGroup)
+
 	for {
 		select {
 		// Handle incoming connections
@@ -114,3 +120,25 @@ func (s *FSDService) resolveAndListen() (listener *net.TCPListener, err error) {
 
 	return listener, nil
 }
+
+func (s *FSDService) heartbeatWorker(ctx context.Context, wg *sync.WaitGroup) {
+	defer wg.Done()
+
+	heartbeatPacket := "#DLSERVER:*:0:0" + protocol.PacketDelimiter
+
+	ticker := time.NewTicker(30 * time.Second)
+	defer ticker.Stop()
+
+	// Send server heartbeat every 30 seconds
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			servercontext.PostOffice().ForEachRegistered(func(name string, address postoffice.Address) bool {
+				address.SendMail(heartbeatPacket)
+				return true
+			})
+		}
+	}
+}