feat(agent): 默认回环监听并自动建立 SSH 隧道并发布 v1.4.0

internal/frp/agent_tunnel_test.go

@@ -0,0 +1,35 @@
+package frp
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"testing"
+)
+
+func TestAgentTunnelBindsLoopbackAndReleasesPort(t *testing.T) {
+	probe, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+	port := probe.Addr().(*net.TCPAddr).Port
+	_ = probe.Close()
+
+	tunnel := newAgentTunnel(context.Background(), 1, port, SSHInstaller{})
+	if err := tunnel.Start(); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := net.Listen("tcp", fmt.Sprintf("127.0.0.1:%d", port)); err == nil {
+		t.Fatal("隧道启动后本地端口应已被占用")
+	}
+	state, _ := tunnel.State()
+	if state != "connected" {
+		t.Fatalf("state=%q, want connected", state)
+	}
+	tunnel.Stop()
+	if listener, err := net.Listen("tcp", fmt.Sprintf("127.0.0.1:%d", port)); err != nil {
+		t.Fatalf("隧道停止后端口未释放: %v", err)
+	} else {
+		_ = listener.Close()
+	}
+}