Implement graceful server shutdown and update port settings

Added signal handling in server.go to support graceful shutdown upon receiving an interrupt or termination signal. Updated docker-compose.yml and Dockerfile to adjust port ranges for better resource management.

Dockerfile

@@ -7,4 +7,4 @@ COPY . .
 RUN go build -o jerusalem-tunnel -v ./...
 ENTRYPOINT ["./jerusalem-tunnel"]
 
-EXPOSE 1024-65535
+EXPOSE 1024-1100

docker-compose.yml

@@ -4,11 +4,11 @@ services:
  jerusalem-tunnel:
  build: .
  ports:
- - "1024-2000:1024-2000"
- - "8901:8901"
+ - "1024-1100:1024-1100"
+ - "1024:1024"
  environment:
- - SERVER_PORT=8901
- - PORT_RANGE=1024...2000
+ - SERVER_PORT=1024
+ - PORT_RANGE=1024...1100
  - SECRET_KEY=2y6sUp8cBSfNDk7Jq5uLm0xHAIOb9ZGqE4hR1WVXtCwKjP3dYzvTn2QiFXe8rMb6
  entrypoint: [ "./jerusalem-tunnel" ]
  restart: always

server.go

@@ -10,6 +10,7 @@ import (
  "log"
  "net"
  "os"
+ "os/signal"
  "sync"
  "syscall"
  "time"
@@ -74,19 +75,44 @@ func (s *Server) StartServer() error {
  }
  log.Printf("Server listening on %s\n", a)
 
+ // Create a channel to listen for an interrupt or termination signal.
+ sigCh := make(chan os.Signal, 1)
+ signal.Notify(sigCh, os.Interrupt, syscall.SIGTERM)
+ shutdownCh := make(chan struct{})
+
+ // Goroutine to handle shutdown signal.
+ go func() {
+ <-sigCh
+ log.Println("Shutdown signal received, closing server...")
+ close(shutdownCh)
+ l.Close() // Close the listener to stop accepting new connections
+ }()
+
  for {
- c, e := l.Accept()
- if e != nil {
- return fmt.Errorf("error accepting connection: %w", e)
- }
- go func() {
- log.Println("Incoming connection")
- if e := s.handleConnection(c); e != nil {
- log.Printf("Connection exited with error: %v\n", e)
- } else {
- log.Println("Connection exited")
+ select {
+ case <-shutdownCh:
+ log.Println("Server gracefully shut down")
+ return nil
+ default:
+ c, e := l.Accept()
+ if e != nil {
+ select {
+ case <-shutdownCh:
+ log.Println("Listener closed, shutting down connection handler")
+ return nil
+ default:
+ return fmt.Errorf("error accepting connection: %w", e)
+ }
  }
- }()
+ go func() {
+ log.Println("Incoming connection")
+ if e := s.handleConnection(c); e != nil {
+ log.Printf("Connection exited with error: %v\n", e)
+ } else {
+ log.Println("Connection exited")
+ }
+ }()
+ }
  }
 }