Function TestConn_PreferredDERP

tailnet/conn_test.go:251–278

TestConn_PreferredDERP tests that we only trigger the NodeCallback when we have a preferred DERP server.

(t *testing.T)

// TestConn_PreferredDERP tests that we only trigger the NodeCallback when we have a preferred DERP server.
func TestConn_PreferredDERP(t *testing.T) {
	t.Parallel()
	ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitShort)
	defer cancel()
	logger := testutil.Logger(t)
	derpMap, _ := tailnettest.RunDERPAndSTUN(t)
	conn, err := tailnet.NewConn(&tailnet.Options{
		Addresses: []netip.Prefix{tailnet.TailscaleServicePrefix.RandomPrefix()},
		Logger:    logger.Named("w1"),
		DERPMap:   derpMap,
	})
	require.NoError(t, err)
	defer func() {
		err := conn.Close()
		require.NoError(t, err)
	}()
	// buffer channel so callback doesn't block
	nodes := make(chan *tailnet.Node, 50)
	conn.SetNodeCallback(func(node *tailnet.Node) {
		nodes <- node
	})
	select {
	case node := <-nodes:
		require.Equal(t, 1, node.PreferredDERP)
	case <-ctx.Done():
		t.Fatal("timed out waiting for node")
	}
}

// TestConn_UpdateDERP tests that when update the DERP map we pick a new
// preferred DERP server and new connections can be made from clients.