add: debian file, perform various fixes

cmd/watcher/watcher.go

@@ -8,6 +8,7 @@ import (
 	"flag"
 	"fmt"
 	"net/http"
+	"sync"
 	"time"
 
 	"connectrpc.com/connect"
@@ -19,6 +20,8 @@ import (
 	"github.com/pion/webrtc/v3"
 	"github.com/pion/webrtc/v3/pkg/media"
 	"github.com/rs/zerolog/log"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -46,18 +49,6 @@ func main() {
 		fmt.Sprintf("https://%s/", *signalerServer),
 		connect.WithGRPC(),
 	)
-	authToken, err := client.CreateAuthToken(ctx, connect.NewRequest(&pb.CreateAuthTokenRequest{
-		Home: cfg.HomeName,
-		Type: &pb.CreateAuthTokenRequest_Camera_{
-			Camera: &pb.CreateAuthTokenRequest_Camera{
-				Id: cfg.CameraName,
-			},
-		},
-	}))
-	if err != nil {
-		log.Fatal().Err(err).Msg("failed to get auth token")
-	}
-	token := authToken.Msg.GetToken()
 
 	vid, err := h264video.Default.Get()
 	if err != nil {
@@ -78,6 +69,11 @@ func main() {
 	sensorCh, sensorDone := sensors.Join()
 	defer sensorDone()
 
+	token, err := getAuthToken(ctx, client, cfg)
+	if err != nil {
+		log.Fatal().Err(err).Msg("failed to get auth token")
+	}
+
 	go handleSensor(ctx, client, token, sensorCh)
 
 	// Create a new RTCPeerConnection
@@ -87,6 +83,14 @@ func main() {
 		// Wait for a session request
 		session, err := client.PopSession(ctx, withAuth(token, &pb.PopSessionRequest{}))
 		if err != nil {
+			if s, ok := status.FromError(err); ok && s.Code() == codes.NotFound {
+				// try getting a new token
+				token, err = getAuthToken(ctx, client, cfg)
+				if err != nil {
+					log.Fatal().Err(err).Msg("failed to recreate auth token")
+				}
+				continue
+			}
 			log.Error().Err(err).Msg("error creating session")
 			continue
 		}
@@ -94,6 +98,22 @@ func main() {
 	}
 }
 
+func getAuthToken(ctx context.Context, client servicepb.SignalerServiceClient, cfg *config.Config) (string, error) {
+	authToken, err := client.CreateAuthToken(ctx, connect.NewRequest(&pb.CreateAuthTokenRequest{
+		Home: cfg.HomeName,
+		Type: &pb.CreateAuthTokenRequest_Camera_{
+			Camera: &pb.CreateAuthTokenRequest_Camera{
+				Id: cfg.CameraName,
+			},
+		},
+	}))
+	if err != nil {
+		return "", fmt.Errorf("CreateAuthToken failed: %w", err)
+	}
+	token := authToken.Msg.GetToken()
+	return token, nil
+}
+
 func handleSensor(ctx context.Context, client servicepb.SignalerServiceClient, token string, ch <-chan *pb.Sample) {
 	for {
 		var sample *pb.Sample
@@ -111,76 +131,12 @@ func handleSensor(ctx context.Context, client servicepb.SignalerServiceClient, t
 	}
 }
 
-func handleSession(ctx context.Context, client servicepb.SignalerServiceClient, token string, session *connect.Response[pb.Session], vid *h264video.Video) {
+func getIceConnection(ctx context.Context, peerConnection *webrtc.PeerConnection, client servicepb.SignalerServiceClient, token string, session *connect.Response[pb.Session]) (context.Context, error) {
-	var err error
-	log.Debug().Msg("new session")
-
-	peerConnection, err := webrtc.NewPeerConnection(webrtc.Configuration{
-		ICEServers: []webrtc.ICEServer{
-			{
-				URLs: []string{"stun:stun.l.google.com:19302"},
-			},
-		},
-	})
-	if err != nil {
-		log.Info().Err(err).Msg("failed to get a connection")
-		return
-	}
-
-	// connect to the video stream; the cleanup is done in the goroutine which
-	// consumes the framess
-	ch, trackCodec, cleanUp := vid.Join()
-	// Create a video track
-	videoTrack, videoTrackErr := webrtc.NewTrackLocalStaticSample(webrtc.RTPCodecCapability{MimeType: trackCodec}, "video", "pion")
-	if videoTrackErr != nil {
-		log.Info().Err(videoTrackErr).Msg("Failed to create video track")
-		return
-	}
-
-	rtpSender, err := peerConnection.AddTrack(videoTrack)
-	if err != nil {
-		log.Info().Err(err).Msg("Failed to add track to connection")
-	}
-
 	// We use the cancel func to signal that the stream is ready
 	iceConnectedCtx, iceConnectedCtxCancel := context.WithCancel(context.Background())
-	defer func() {
+	iceDisconnectedCtx, iceDeconnectedCtxCancel := context.WithCancel(ctx)
-		if err := peerConnection.Close(); err != nil {
+	readyToSend := sync.WaitGroup{}
-			log.Debug().Err(err).Msg("cannot close peerConnection")
+	readyToSend.Add(1)
-		}
-	}()
-
-	// Read incoming RTCP packets
-	// Before these packets are returned they are processed by interceptors. For things
-	// like NACK this needs to be called.
-	go func() {
-		rtcpBuf := make([]byte, 1500)
-		for {
-			if _, _, err := rtpSender.Read(rtcpBuf); err != nil {
-				return
-			}
-		}
-	}()
-
-	go func() {
-		defer cleanUp()
-		readyToSend := false
-		for frame := range ch {
-			select {
-			case <-iceConnectedCtx.Done():
-				readyToSend = true
-			default:
-				// do nothing
-			}
-			if !readyToSend {
-				continue
-			}
-			if err := videoTrack.WriteSample(media.Sample{Data: frame, Duration: time.Millisecond * 33}); err != nil {
-				log.Err(err).Msg("failed to write sample")
-				return
-			}
-		}
-	}()
 
 	// Set the handler for ICE connection state
 	// This will notify you when the peer has connected/disconnected
@@ -193,7 +149,6 @@ func handleSession(ctx context.Context, client servicepb.SignalerServiceClient,
 
 	// Set the handler for Peer connection state
 	// This will notify you when the peer has connected/disconnected
-	exitCh := make(chan struct{})
 	peerConnection.OnConnectionStateChange(func(s webrtc.PeerConnectionState) {
 		log.Debug().Msgf("Peer Connection State has changed: %s\n", s.String())
 
@@ -201,15 +156,12 @@ func handleSession(ctx context.Context, client servicepb.SignalerServiceClient,
 			// Wait until PeerConnection has had no network activity for 30 seconds or another failure. It may be reconnected using an ICE Restart.
 			// Use webrtc.PeerConnectionStateDisconnected if you are interested in detecting faster timeout.
 			// Note that the PeerConnection may come back from PeerConnectionStateDisconnected.
-			close(exitCh)
+			iceDeconnectedCtxCancel()
-			return
-		}
-		if s == webrtc.PeerConnectionStateDisconnected {
-			close(exitCh)
 		}
 	})
 
 	peerConnection.OnICECandidate(func(i *webrtc.ICECandidate) {
+		readyToSend.Wait()
 		if i == nil {
 			if _, err := client.CreateIceMessage(ctx, withAuth(token, &pb.CreateIceMessageRequest{
 				SessionIdentifier: session.Msg.GetId(),
@@ -226,6 +178,7 @@ func handleSession(ctx context.Context, client servicepb.SignalerServiceClient,
 		if c.UsernameFragment != nil {
 			usernameFragment = proto.String(*c.UsernameFragment)
 		}
+		log.Info().Msgf("got candidate %+v", c)
 		client.CreateIceMessage(ctx, withAuth(token, &pb.CreateIceMessageRequest{
 			SessionIdentifier: session.Msg.GetId(),
 			IceMessage: &pb.IceMessage{
@@ -240,19 +193,71 @@ func handleSession(ctx context.Context, client servicepb.SignalerServiceClient,
 			},
 		}))
 	})
-	log.Info().Msg("Spawning helper")
 
-	// helper which sends answers, waits for
+	// Get the offer from the other
+	msg, err := client.PopIceMessage(iceDisconnectedCtx, withAuth(token, &pb.PopIceMessageRequest{
+		SessionIdentifier: session.Msg.GetId(),
+	}))
+	if err != nil {
+		log.Info().Err(err).Msg("failed to pop ice message")
+	}
+	iceSession := msg.Msg.GetSession()
+
+	switch iceSession.SdpType {
+	case int64(webrtc.SDPTypeOffer):
+		offer := webrtc.SessionDescription{
+			Type: webrtc.SDPType(iceSession.SdpType),
+			SDP:  iceSession.Sdp,
+		}
+
+		if err := peerConnection.SetRemoteDescription(offer); err != nil {
+			log.Warn().Err(err).Msg("failed to set remote description")
+		}
+	default:
+		log.Info().Msgf("unexpected sdp type: %v", webrtc.SDPType(iceSession.SdpType).String())
+	}
+	log.Info().Msg("Accepted promise!")
+
+	// Send back an answer
+	answer, err := peerConnection.CreateAnswer(nil)
+	if err != nil {
+		log.Debug().Err(err).Msg("Candidate failed")
+	}
+
+	if err := peerConnection.SetLocalDescription(answer); err != nil {
+		log.Info().Err(err).Msg("Failed to set local description")
+	}
+
+	_, err = client.CreateIceMessage(iceDisconnectedCtx, withAuth(token, &pb.CreateIceMessageRequest{
+		SessionIdentifier: session.Msg.GetId(),
+		IceMessage: &pb.IceMessage{
+			Type: &pb.IceMessage_Session{
+				Session: &pb.IceSessionDescription{
+					SdpType: int64(answer.Type),
+					Sdp:     answer.SDP,
+				},
+			},
+		},
+	}))
+	if err != nil {
+		log.Info().Err(err).Msg("Failed to send answer")
+	}
+	readyToSend.Done()
+
+	// TODO: do we add the video right here?
+
+	// Go into a loop processing ice candidates
 
 	// Add ICE candidates from remote
+	go func() {
 		for {
 			select {
-		case <-exitCh:
+			case <-iceDisconnectedCtx.Done():
 				return
 			default:
 				// check for another message
 			}
-		msg, err := client.PopIceMessage(ctx, withAuth(token, &pb.PopIceMessageRequest{
+			msg, err := client.PopIceMessage(iceDisconnectedCtx, withAuth(token, &pb.PopIceMessageRequest{
 				SessionIdentifier: session.Msg.GetId(),
 			}))
 			if err != nil {
@@ -274,51 +279,117 @@ func handleSession(ctx context.Context, client servicepb.SignalerServiceClient,
 				}); err != nil {
 					log.Warn().Err(err).Msg("failed to add ice candidate")
 				}
-
-			// Send back an answer
-			answer, err := peerConnection.CreateAnswer(nil)
-			if err != nil {
-				log.Debug().Msg("Candidate failed")
-				continue
-			}
-
-			if err := peerConnection.SetLocalDescription(answer); err != nil {
-				log.Info().Err(err).Msg("Failed to set local description")
-			}
-
-			_, err = client.CreateIceMessage(ctx, withAuth(token, &pb.CreateIceMessageRequest{
-				SessionIdentifier: session.Msg.GetId(),
-				IceMessage: &pb.IceMessage{
-					Type: &pb.IceMessage_Session{
-						Session: &pb.IceSessionDescription{
-							SdpType: int64(answer.Type),
-							Sdp:     answer.SDP,
-						},
-					},
-				},
-			}))
-			if err != nil {
-				log.Info().Err(err).Msg("Failed to send answer")
-			}
 			case *pb.IceMessage_Session:
-			iceSession := msg.Msg.GetSession()
 
-			switch iceSession.SdpType {
-			case int64(webrtc.SDPTypeOffer):
-				offer := webrtc.SessionDescription{
-					Type: webrtc.SDPType(iceSession.SdpType),
-					SDP:  iceSession.Sdp,
-				}
-
-				if err := peerConnection.SetRemoteDescription(offer); err != nil {
-					log.Warn().Err(err).Msg("failed to set remote description")
-				}
-			default:
-				log.Info().Msgf("unexpected sdp type: %v", webrtc.SDPType(iceSession.SdpType).String())
-			}
-			log.Info().Msg("Accepted promise!")
 			case *pb.IceMessage_NoMoreCandidates:
 				// do nothing
 			}
 		}
+	}()
+
+	select {
+	case <-iceConnectedCtx.Done():
+		// Success; return the connection
+		return iceDisconnectedCtx, nil
+	case <-iceDisconnectedCtx.Done():
+		// No connection; return error
+		return ctx, fmt.Errorf("failed to create connection: ICE disconnected")
+	}
+}
+
+func handleSession(ctx context.Context, client servicepb.SignalerServiceClient, token string, session *connect.Response[pb.Session], vid *h264video.Video) {
+	log.Debug().Msg("new session")
+
+	// connect to the video stream; the cleanup is done in the goroutine which
+	// consumes the framess
+	ch, trackCodec, cleanUp := vid.Join()
+	defer cleanUp()
+
+	// Create a video track
+	videoTrack, err := webrtc.NewTrackLocalStaticSample(webrtc.RTPCodecCapability{MimeType: trackCodec}, "video", "pion")
+	if err != nil {
+		log.Info().Err(err).Msg("Failed to create video track")
+		return
+	}
+
+	peerConnection, err := webrtc.NewPeerConnection(webrtc.Configuration{
+		ICEServers: []webrtc.ICEServer{
+			{
+				URLs: []string{"stun:stun.l.google.com:19302"},
+			},
+		},
+	})
+	if err != nil {
+		log.Err(err).Msg("failed to make connection")
+	}
+
+	rtpSender, err := peerConnection.AddTrack(videoTrack)
+	if err != nil {
+		log.Info().Err(err).Msg("Failed to add track to connection")
+		return
+	}
+
+	disconnectedCtx, err := getIceConnection(ctx, peerConnection, client, token, session)
+	if err != nil {
+		log.Err(err).Msg("failed creating ice connection")
+	}
+
+	log.Info().Msgf("State is %+v", rtpSender.Transport().State())
+
+	// Read incoming RTCP packets
+	// Before these packets are returned they are processed by interceptors. For things
+	// like NACK this needs to be called.
+	go func() {
+		rtcpBuf := make([]byte, 1500)
+		for {
+			select {
+			case <-disconnectedCtx.Done():
+				return
+			default:
+				// do nothing
+			}
+			if _, _, err := rtpSender.Read(rtcpBuf); err != nil {
+				return
+			}
+		}
+	}()
+
+	// Start a routine to send frames from a buffer
+	var frame []byte
+	var frameLock sync.Mutex
+	go func() {
+		ticker := time.NewTicker(time.Millisecond * 30)
+		for {
+			select {
+			case <-disconnectedCtx.Done():
+				return
+			case <-ticker.C:
+				// do nothing
+			}
+			frameLock.Lock()
+			myFrame := frame
+			frame = nil
+			frameLock.Unlock()
+			if myFrame == nil {
+				continue
+			}
+			if err := videoTrack.WriteSample(media.Sample{Data: myFrame, Duration: time.Millisecond * 33}); err != nil {
+				log.Err(err).Msg("failed to write sample")
+				return
+			}
+		}
+	}()
+
+	for myFrame := range ch {
+		select {
+		case <-disconnectedCtx.Done():
+			return
+		default:
+			// do nothing
+		}
+		frameLock.Lock()
+		frame = myFrame
+		frameLock.Unlock()
+	}
+	// TODO: Video ended; close the connection
 }

dbuild/DEBIAN/control

@@ -0,0 +1,5 @@
+Package: watcher
+Version: 0.2
+Maintainer: Charles
+Architecture: all
+Description: Watches cameras and temp sensors

dbuild/DEBIAN/postinst

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+systemctl daemon-reload
+# Make sure its enabled
+systemctl enable --now watcher
+# Restart it; it might have already been installed and running
+systemctl restart watcher

dbuild/etc/systemd/system/watcher.service

@@ -0,0 +1,14 @@
+# Install to /etc/systemd/system/watcher.service
+[Unit]
+Description=Run watcher
+After=network-online.target
+Wants=network-online.target systemd-networkd-wait-online.service
+
+[Service]
+Type=exec
+ExecStart=/usr/local/bin/watcher --watcher_config /etc/watcher_config.yaml --watcher_name /etc/watcher_name.txt
+Restart=on-failure
+RestartSec=5s
+
+[Install]
+WantedBy=multi-user.target

dbuild/etc/systemd/system/watcher.systemd

@@ -0,0 +1,14 @@
+# Install to /etc/systemd/system/watcher.service
+[Unit]
+Description=Run watcher
+After=network-online.target
+Wants=network-online.target systemd-networkd-wait-online.service
+
+[Service]
+Type=exec
+ExecStart=/usr/local/bin --watcher_config /etc/watcher.yaml
+Restart=on-failure
+RestartSec=5s
+
+[Install]
+WantedBy=multi-user.target

dbuild/etc/watcher_config.yaml

@@ -0,0 +1,20 @@
+home: Sunnyvale
+name: Office
+h264:
+  binary: "/usr/bin/libcamera-vid"
+  arguments:
+  - "-n"
+  - "-t"
+  - "0"
+  - "--codec"
+  - "h264"
+  - "--mode"
+  - "1640:1232"
+  - "--inline"
+  - "-o"
+  - "-"
+sensor:
+  binary: "/usr/bin/python3"
+  arguments:
+  - "/usr/local/bin/temperature.py"
+sensor_rate_ms: 10000

dbuild/usr/local/bin/temperature.py

@@ -0,0 +1,17 @@
+import bme280
+import smbus2
+from time import sleep
+
+port = 1
+address = 0x77 # Adafruit BME280 address. Other BME280s may be different
+bus = smbus2.SMBus(port)
+
+bme280.load_calibration_params(bus,address)
+
+while True:
+    bme280_data = bme280.sample(bus,address)
+    humidity  = bme280_data.humidity
+    pressure  = bme280_data.pressure
+    ambient_temperature = bme280_data.temperature
+    print(humidity, pressure, ambient_temperature)
+    sleep(1)

internal/watcher/config/config.go

@@ -25,20 +25,23 @@ type Config struct {
 	SensorRateMS int64  `yaml:"sensor_rate_ms"`
 }
 
-func New(source []byte) (*Config, error) {
+func New(source []byte, name string) (*Config, error) {
 	config := &Config{}
 	if err := yaml.Unmarshal(source, config); err != nil {
 		return nil, fmt.Errorf("failed to parse config: %w", err)
 	}
+	config.CameraName = name
 	return config, nil
 }
 
 type Mod struct {
 	filePath string
+	namePath string
 }
 
 func (m *Mod) RegisterFlags(fs *flag.FlagSet) {
 	fs.StringVar(&m.filePath, "watcher_config", "", "path to the watcher configuration")
+	fs.StringVar(&m.namePath, "watcher_name", "/var/lib/dbus/machine-id", "location of the file to pull name from")
 }
 
 func (m *Mod) Get() (*Config, error) {
@@ -47,7 +50,13 @@ func (m *Mod) Get() (*Config, error) {
 		return nil, fmt.Errorf("failed to read file %q: %w", m.filePath, err)
 	}
 
-	config, err := New(bytes)
+	// Override name using a unique ID; we can let users name things in the app
+	myID, err := os.ReadFile(m.namePath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read machine ID from %q", m.namePath)
+	}
+
+	config, err := New(bytes, string(myID))
 	if err != nil {
 		return nil, err
 	}

pkg/signaler/signaler.go

@@ -223,7 +223,16 @@ func (s *Server) PopSession(ctx context.Context, request *connect.Request[pb.Pop
 	ch := s.sessionsByCamera[authToken.Uid]
 	s.mu.Unlock()
 
-	sess := <-ch
+	var sess *session
+	tick := time.NewTicker(time.Second * 30)
+	defer tick.Stop()
+	select {
+	case sess = <-ch:
+		// OK
+	case <-tick.C:
+		// have them retry
+		return nil, connect.NewError(connect.CodeDeadlineExceeded, fmt.Errorf("try again"))
+	}
 
 	if sess == nil {
 		return nil, status.Errorf(codes.DataLoss, "someone else stole the session")

prod.yaml

@@ -17,7 +17,7 @@ spec:
     spec:
       containers:
       - name: signaler
-        image: us-central1-docker.pkg.dev/home-sensors-400805/signaler/image:20231003-0032
+        image: us-central1-docker.pkg.dev/home-sensors-400805/signaler/image:20240110-2245
         command:
         - /signaler
         ports:
@@ -81,3 +81,10 @@ spec:
   domains:
     - home.chathaway.codes
     - www.home.chathaway.codes
+---
+apiVersion: cloud.google.com/v1
+kind: BackendConfig
+metadata:
+  name: my-bsc-backendconfig
+spec:
+  timeoutSec: 40

rpi_camera.yaml

@@ -10,25 +10,11 @@ h264:
   - "h264"
   - "--mode"
   - "1640:1232"
-  - "--denoise"
-  - "off"
   - "--inline"
   - "-o"
   - "-"
-ivf:
-  binary: "/usr/bin/ffmpeg"
-  arguments:
-  - "-i"
-  - "-"
-  - "-g"
-  - "30"
-  - "-b:v"
-  - "2M"
-  - "-f"
-  - "ivf"
-  - "-"
 sensor:
   binary: "/usr/bin/python3"
   arguments:
-  - "/home/charles/temperature.py"
+  - "/usr/local/bin/temperature.py"
 sensor_rate_ms: 10000

scripts/build_deb.sh

@@ -0,0 +1,34 @@
+#!/bin/bash
+
+mkdir -p dbuild/usr/local/bin
+mkdir -p dbuild/etc/
+mkdir -p dbuild/etc/systemd/system/
+mkdir -p dbuild/DEBIAN
+
+cat <<EOF > dbuild/DEBIAN/control
+Package: watcher
+Version: 0.2
+Maintainer: Charles
+Architecture: all
+Description: Watches cameras and temp sensors
+EOF
+
+cat <<EOF > dbuild/DEBIAN/postinst
+#!/bin/bash
+
+systemctl daemon-reload
+# Make sure its enabled
+systemctl enable --now watcher
+# Restart it; it might have already been installed and running
+systemctl restart watcher
+EOF
+chmod +x dbuild/DEBIAN/postinst
+
+GOOS=linux GOARCH=arm64 go build -o dbuild/usr/local/bin/watcher ./cmd/watcher
+
+cp ./rpi_camera.yaml dbuild/etc/watcher_config.yaml
+cp ./watcher.systemd dbuild/etc/systemd/system/watcher.service
+cp ./temperature.py dbuild/usr/local/bin/
+
+
+dpkg-deb --build dbuild

ui/android/app/src/main/AndroidManifest.xml

@@ -31,5 +31,6 @@
             android:value="2" />
     </application>
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+    <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
 </manifest>

ui/lib/call.dart

@@ -38,15 +38,16 @@ class CallState extends State<Call> {
     logger.i("Init remote renderer");
     await _remoteRenderer.initialize();
     logger.i("Creating session");
-    await _createSesson();
+    await _createSession();
   }
 
-  _createSesson() async {
+  _createSession() async {
     var callOptions = CallOptions(metadata: {
       'Authorization': await widget.sessionService.getAuthToken(widget.home)
     });
 
     var cancelCreate = Completer();
+    var sendIceCandidates = Completer();
 
     var clientSession = await widget.client.createSession(
         pb.CreateSessionRequest(
@@ -73,6 +74,8 @@ class CallState extends State<Call> {
     };
 
     peerConnection.onIceCandidate = (candidate) async {
+      await sendIceCandidates.future;
+      logger.i("Sending ICE candidate");
       if (candidate.candidate == null) {
         await widget.client.createIceMessage(
             CreateIceMessageRequest(
@@ -99,16 +102,15 @@ class CallState extends State<Call> {
     };
 
     peerConnection.onIceConnectionState = (state) {
-      statusLine = "Ice state now $state";
+      statusLine = "$state";
       setState(() {});
-      logger.i("Ice state now $state");
 
       switch (state) {
-        case RTCIceConnectionState.RTCIceConnectionStateClosed:
+        //case RTCIceConnectionState.RTCIceConnectionStateClosed:
-        case RTCIceConnectionState.RTCIceConnectionStateDisconnected:
+        //case RTCIceConnectionState.RTCIceConnectionStateDisconnected:
         case RTCIceConnectionState.RTCIceConnectionStateFailed:
           cancelCreate.complete(CallCancelled());
-          _connect();
+        //_connect();
         default:
         // do nothing
       }
@@ -136,7 +138,6 @@ class CallState extends State<Call> {
     var offer = await peerConnection.createOffer();
     await peerConnection.setLocalDescription(offer);
     // Send offer through signaling server
-    logger.i("Offer is $offer");
     await widget.client.createIceMessage(
         pb.CreateIceMessageRequest(
           sessionIdentifier: clientSession.id,
@@ -149,6 +150,20 @@ class CallState extends State<Call> {
         ),
         options: callOptions);
 
+    // Expect back a response
+    var someResponse = await Future.any([
+      widget.client.popIceMessage(
+          pb.PopIceMessageRequest(sessionIdentifier: clientSession.id),
+          options: callOptions),
+      cancelCreate.future,
+    ]);
+    var resp = someResponse as pb.IceMessage;
+    var session = resp.session;
+    await peerConnection
+        .setRemoteDescription(RTCSessionDescription(session.sdp, "answer"));
+
+    sendIceCandidates.complete();
+
     // Get candidates from remote
     while (true) {
       var someResponse = await Future.any([
@@ -168,10 +183,6 @@ class CallState extends State<Call> {
             resp.candidate.sdpLineIndex));
       } else if (resp.hasNoMoreCandidates()) {
         logger.i("No more candidates from remote");
-      } else if (resp.hasSession()) {
-        var session = resp.session;
-        await peerConnection
-            .setRemoteDescription(RTCSessionDescription(session.sdp, "answer"));
         break;
       }
     }
@@ -183,7 +194,7 @@ class CallState extends State<Call> {
       Text(widget.cameraID.id),
       Text(statusLine),
       SizedBox(
-          height: 480,
+          height: 320,
           child: _ready
               ? RTCVideoView(_remoteRenderer)
               : const Text("Loading...")),

ui/lib/main.dart

@@ -1,3 +1,5 @@
+import 'dart:collection';
+
 import 'package:flutter/material.dart';
 //import 'package:grpc/grpc_web.dart';
 import 'package:grpc/grpc.dart';
@@ -36,9 +38,9 @@ class MyApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
-      title: 'Flutter Demo',
+      title: 'Home Sensors',
-      theme: ThemeData(
+      theme: ThemeData.dark(
-        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
+        // colorScheme: ColorScheme.fromSeed(seedColor: Colors.black87),
         useMaterial3: true,
       ),
       home: MyHomePage(
@@ -75,8 +77,8 @@ class MyHomePage extends StatefulWidget {
 
 class _MyHomePageState extends State<MyHomePage> {
   String topMessage = "Creating session...";
-  List<Call> camerasToRender = [];
+  List<Widget> camerasToRender = [];
-  List<Widget> samples = [];
+  Map<String, Widget> cameraSamples = {};
 
   @override
   void initState() {
@@ -100,8 +102,11 @@ class _MyHomePageState extends State<MyHomePage> {
         .listSamples(ListSamplesRequest(), options: callOptions);
 
     for (var sample in resp.samples) {
-      samples
+      if (sample.type == Sample_Type.TEMPERATURE_C) {
-          .add(Text("${sample.type}: ${sample.reading} on ${sample.cameraId}"));
+        var reading = (sample.reading * 9.0 / 5.0) + 32;
+        cameraSamples[sample.cameraId.id] =
+            Text("${reading.toStringAsFixed(2)} f");
+      }
     }
     setState(() {});
   }
@@ -113,12 +118,22 @@ class _MyHomePageState extends State<MyHomePage> {
     var cameras = await widget.client
         .listCameras(ListCamerasRequest(), options: callOptions);
 
+    cameras.cameras.sort((a, b) => a.identifier.id.compareTo(b.identifier.id));
+    camerasToRender = [];
     for (var camera in cameras.cameras) {
-      camerasToRender.add(Call(
+      List<Widget> children = [
+        Call(
           widget.client,
           widget.sessionService,
           cameraID: camera.identifier,
           home: widget.home,
+        ),
+      ];
+      if (cameraSamples.containsKey(camera.identifier.id)) {
+        children.add(cameraSamples[camera.identifier.id]!);
+      }
+      camerasToRender.add(Column(
+        children: children,
       ));
     }
     setState(() {});
@@ -134,12 +149,7 @@ class _MyHomePageState extends State<MyHomePage> {
     // than having to individually change instances of widgets.
     return Scaffold(
         appBar: AppBar(
-          // TRY THIS: Try changing the color here to a specific color (to
-          // Colors.amber, perhaps?) and trigger a hot reload to see the AppBar
-          // change color while the other colors stay the same.
           backgroundColor: Theme.of(context).colorScheme.inversePrimary,
-          // Here we take the value from the MyHomePage object that was created by
-          // the App.build method, and use it to set our appbar title.
           title: Text(widget.title),
         ),
         body: SingleChildScrollView(
@@ -150,7 +160,6 @@ class _MyHomePageState extends State<MyHomePage> {
             children: <Widget>[
                   Text(topMessage),
                 ] +
-                samples +
                 camerasToRender,
           ),
         ));

watcher.systemd

@@ -0,0 +1,14 @@
+# Install to /etc/systemd/system/watcher.service
+[Unit]
+Description=Run watcher
+After=network-online.target
+Wants=network-online.target systemd-networkd-wait-online.service
+
+[Service]
+Type=exec
+ExecStart=/usr/local/bin/watcher --watcher_config /etc/watcher_config.yaml --watcher_name /etc/watcher_name.txt
+Restart=on-failure
+RestartSec=5s
+
+[Install]
+WantedBy=multi-user.target