TUN-3635: Send event when unregistering tunnel for gracful shutdown so /ready endpoint reports down status befoe connections finish handling pending requests.

connection/connection_test.go

@@ -27,7 +27,6 @@ var (
 		Scheme: "https",
 		Host:   "connectiontest.argotunnel.com",
 	}
-	testObserver  = NewObserver(&log, &log, false)
 	testLargeResp = make([]byte, largeFileSize)
 )
 

connection/event.go

@@ -22,4 +22,6 @@ const (
 	SetURL
 	// RegisteringTunnel means the non-named tunnel is registering its connection.
 	RegisteringTunnel
+	// We're unregistering tunnel from the edge in preparation for a disconnect
+	Unregistering
 )

connection/h2mux_test.go

@@ -33,7 +33,7 @@ func newH2MuxConnection(t require.TestingT) (*h2muxConnection, *h2mux.Muxer) {
 	edgeMuxChan := make(chan *h2mux.Muxer)
 	go func() {
 		edgeMuxConfig := h2mux.MuxerConfig{
-			Log: testObserver.log,
+			Log: &log,
 			Handler: h2mux.MuxedStreamFunc(func(stream *h2mux.MuxedStream) error {
 				// we only expect RPC traffic in client->edge direction, provide minimal support for mocking
 				require.True(t, stream.IsRPCStream())
@@ -47,6 +47,7 @@ func newH2MuxConnection(t require.TestingT) (*h2muxConnection, *h2mux.Muxer) {
 		edgeMuxChan <- edgeMux
 	}()
 	var connIndex = uint8(0)
+	testObserver := NewObserver(&log, &log, false)
 	h2muxConn, err, _ := NewH2muxConnection(testConfig, testMuxerConfig, originConn, connIndex, testObserver, nil)
 	require.NoError(t, err)
 	return h2muxConn, <-edgeMuxChan

connection/http2.go

@@ -142,6 +142,7 @@ func (c *http2Connection) serveControlStream(ctx context.Context, respWriter *ht
 		c.stoppedGracefully = true
 	}
 
+	c.observer.sendUnregisteringEvent(c.connIndex)
 	rpcClient.GracefulShutdown(ctx, c.config.GracePeriod)
 	c.observer.log.Info().Uint8(LogFieldConnIndex, c.connIndex).Msg("Unregistered tunnel connection")
 	return nil

connection/http2_test.go

@@ -35,7 +35,7 @@ func newTestHTTP2Connection() (*http2Connection, net.Conn) {
 		testConfig,
 		&NamedTunnelConfig{},
 		&pogs.ConnectionOptions{},
-		testObserver,
+		NewObserver(&log, &log, false),
 		connIndex,
 		mockConnectedFuse{},
 		nil,
@@ -256,7 +256,9 @@ func TestGracefulShutdownHTTP2(t *testing.T) {
 		registered:   make(chan struct{}),
 		unregistered: make(chan struct{}),
 	}
+	events := &eventCollectorSink{}
 	http2Conn.newRPCClientFunc = rpcClientFactory.newMockRPCClient
+	http2Conn.observer.RegisterSink(events)
 	shutdownC := make(chan struct{})
 	http2Conn.gracefulShutdownC = shutdownC
 
@@ -301,6 +303,11 @@ func TestGracefulShutdownHTTP2(t *testing.T) {
 
 	cancel()
 	wg.Wait()
+
+	events.assertSawEvent(t, Event{
+		Index:     http2Conn.connIndex,
+		EventType: Unregistering,
+	})
 }
 
 func benchmarkServeHTTP(b *testing.B, test testRequest) {

connection/observer.go

@@ -117,6 +117,10 @@ func (o *Observer) SendReconnect(connIndex uint8) {
 	o.sendEvent(Event{Index: connIndex, EventType: Reconnecting})
 }
 
+func (o *Observer) sendUnregisteringEvent(connIndex uint8) {
+	o.sendEvent(Event{Index: connIndex, EventType: Unregistering})
+}
+
 func (o *Observer) SendDisconnect(connIndex uint8) {
 	o.sendEvent(Event{Index: connIndex, EventType: Disconnected})
 }

connection/observer_test.go

@@ -66,3 +66,21 @@ func TestObserverEventsDontBlock(t *testing.T) {
 		mu.Unlock()
 	}
 }
+
+
+type eventCollectorSink struct {
+	observedEvents []Event
+	mu sync.Mutex
+}
+
+func (s *eventCollectorSink) OnTunnelEvent(event Event) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.observedEvents = append(s.observedEvents, event)
+}
+
+func (s *eventCollectorSink) assertSawEvent(t *testing.T, event Event) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	assert.Contains(t, s.observedEvents, event)
+}

connection/rpc.go

@@ -291,6 +291,8 @@ func (h *h2muxConnection) registerNamedTunnel(
 }
 
 func (h *h2muxConnection) unregister(isNamedTunnel bool) {
+	h.observer.sendUnregisteringEvent(h.connIndex)
+
 	unregisterCtx, cancel := context.WithTimeout(context.Background(), h.config.GracePeriod)
 	defer cancel()