Allow restarting a sensor from web UI

client/main.go

@@ -58,6 +58,13 @@ func main() {
 
 	configureHeartbeat(mqttClient, *sensorSource)
 
+	mqttClient.subscribeRestart(func(messageString string) {
+		if *sensorSource == messageString {
+			logger.Println("Received restart message, restarting app now")
+			os.Exit(0)
+		}
+	})
+
 	lastStatus := UNKNOWN
 	var currentStatus string
 	for true {

client/mqtt.go

@@ -3,13 +3,17 @@ package main
 import (
 	"fmt"
 	"strconv"
+	"sync"
 
 	mqtt "github.com/eclipse/paho.mqtt.golang"
 	"github.com/gofrs/uuid"
 )
 
+type fn func(string)
+
 const (
 	sensorHeartbeatChannel = "sensor/heartbeat"
+	restartTopic           = "sensor/restart"
 )
 
 var connectHandler mqtt.OnConnectHandler = func(client mqtt.Client) {
@@ -66,3 +70,14 @@ func (c mqttClient) publishHeartbeat(sensorSource string, timestamp int64) {
 	token := c.client.Publish(sensorHeartbeatChannel, 0, false, text)
 	token.Wait()
 }
+
+func (c mqttClient) subscribeRestart(subscribeHandler fn) {
+	var wg sync.WaitGroup
+	wg.Add(1)
+
+	if token := c.client.Subscribe(restartTopic, 0, func(client mqtt.Client, msg mqtt.Message) {
+		subscribeHandler(string(msg.Payload()))
+	}); token.Wait() && token.Error() != nil {
+		logger.Fatal(token.Error())
+	}
+}

server/frontend/src/SensorPage.js

@@ -15,6 +15,19 @@ class SensorPage extends Component {
     this.state = this.props.location.state
   }
 
+  restartSensor(source) {
+    fetch("/api/sensor/restart", {
+      method: 'POST',
+      credentials: 'same-origin',
+      headers: {
+        'Content-Type': 'application/json'
+      },
+      referrerPolicy: 'no-referrer',
+      body: JSON.stringify({source: source})
+    })
+    .then(r => r.json())
+  }
+
   render() {
     return (
       <SiteWrapper>
@@ -25,6 +38,9 @@ class SensorPage extends Component {
           </Card.Header>
           <Card.Body>
               <p>Last activity: {this.state.timesince}</p>
+              <button onClick={() => this.restartSensor(this.state.source)}>
+                Restart
+              </button>
           </Card.Body>
         </Card>
         <Link to={{pathname: "/"}}><Button color="secondary">Back</Button></Link>

server/main.go

@@ -1,9 +1,11 @@
 package main
 
 import (
+	"encoding/json"
 	"flag"
 	"fmt"
 	"log"
+	"net/http"
 	"os"
 	"strconv"
 	"time"
@@ -38,6 +40,7 @@ const (
 
 var _webServer webServer
 var _redisClient redisClient
+var _mqttClient mqttClient
 
 func newClientHandler() {
 	state, err := _redisClient.ReadAllState()
@@ -48,6 +51,21 @@ func newClientHandler() {
 	}
 }
 
+type Sensor struct {
+	Source string
+}
+
+func sensorRestartHandler(w http.ResponseWriter, req *http.Request) {
+	var sensor Sensor
+	err := json.NewDecoder(req.Body).Decode(&sensor)
+	if err != nil {
+		http.Error(w, "Error parsing request", http.StatusBadRequest)
+		return
+	}
+	_mqttClient.publishSensorRestart(sensor.Source)
+	fmt.Fprintf(w, "{\"status\":\"success\"}")
+}
+
 func main() {
 	logger.Println("Initializing server")
 	flag.Parse()
@@ -119,9 +137,9 @@ func main() {
 
 	messenger := newMessenger(serverConfig.twilioConfig)
 	var delayTimerMap map[string]*time.Timer = make(map[string]*time.Timer)
-	_webServer = newWebServer(serverConfig, newClientHandler)
-	mqttClient := newMQTTClient(serverConfig)
-	mqttClient.Subscribe(sensorStatusChannel, func(messageString string) {
+	_webServer = newWebServer(serverConfig, newClientHandler, sensorRestartHandler)
+	_mqttClient = newMQTTClient(serverConfig)
+	_mqttClient.Subscribe(sensorStatusChannel, func(messageString string) {
 		message := toStruct(messageString)
 		lastMessageString, _ := _redisClient.ReadState(message.Source)
 		lastMessage := toStruct(lastMessageString)
@@ -147,7 +165,7 @@ func main() {
 	})
 
 	var heartbeatTimerMap map[string]*time.Timer = make(map[string]*time.Timer)
-	mqttClient.Subscribe(sensorHeartbeatChannel, func(messageString string) {
+	_mqttClient.Subscribe(sensorHeartbeatChannel, func(messageString string) {
 		heartbeat := toHeartbeat(messageString)
 		currentTimer := heartbeatTimerMap[heartbeat.Source]
 		if currentTimer != nil {

server/mqtt.go

@@ -60,3 +60,8 @@ func (c mqttClient) Subscribe(topic string, subscribeHandler fn) {
 		logger.Fatal(token.Error())
 	}
 }
+
+func (c mqttClient) publishSensorRestart(sensorSource string) {
+	token := c.client.Publish(sensorRestartChannel, 0, false, sensorSource)
+	token.Wait()
+}

server/web.go

@@ -25,33 +25,32 @@ const (
 	// Time allowed to read the next pong message from the peer.
 	pongWait = 60 * time.Second
 
-	publicDir         = "/frontend/build/"
-	channelName       = "sensor"
-	sessionName       = "pi-sensor" // TODO need to make this dynamic?
-	sessionUserKey    = "9024685F-97A4-441E-90D3-F0F11AA7A602"
-	post              = "post"
-	sensorListChannel = "sensor/list"
+	publicDir            = "/frontend/build/"
+	channelName          = "sensor"
+	sessionName          = "pi-sensor" // TODO need to make this dynamic?
+	sessionUserKey       = "9024685F-97A4-441E-90D3-F0F11AA7A602"
+	post                 = "post"
+	get                  = "get"
+	sensorListChannel    = "sensor/list"
+	sensorRestartChannel = "sensor/restart"
 )
 
 var sessionStore *sessions.CookieStore
 
 type newClientHandlerFunc func()
 
-var channel *gosocketio.Channel
-
 type webServer struct {
 	httpServer   *http.Server
 	socketServer *gosocketio.Server
 }
 
-func newWebServer(serverConfig ServerConfig, newClientHandler newClientHandlerFunc) webServer {
+func newWebServer(serverConfig ServerConfig, newClientHandler newClientHandlerFunc, sensorRestartHandler http.HandlerFunc) webServer {
 	router := gmux.NewRouter().StrictSlash(true)
 	socketServer := gosocketio.NewServer(transport.GetDefaultWebsocketTransport())
 	socketServer.On(gosocketio.OnConnection, func(c *gosocketio.Channel) {
-		channel = c
-		// c.BroadcastTo("chat", "message", msg)
 		newClientHandler()
 	})
+
 	router.Handle("/socket.io/", socketServer)
 	oauth2Config := &oauth2.Config{
 		ClientID:     serverConfig.googleConfig.clientId,
@@ -62,6 +61,7 @@ func newWebServer(serverConfig ServerConfig, newClientHandler newClientHandlerFu
 	}
 	sessionStore = sessions.NewCookieStore([]byte(serverConfig.googleConfig.sessionSecret), nil)
 	stateConfig := gologin.DebugOnlyCookieConfig
+	router.Handle("/api/sensor/restart", requireLogin(http.HandlerFunc(sensorRestartHandler))).Methods(post)
 	router.Handle("/google/login", google.StateHandler(stateConfig, google.LoginHandler(oauth2Config, nil)))
 	router.Handle("/google/callback", google.StateHandler(stateConfig, google.CallbackHandler(oauth2Config, issueSession(serverConfig), nil)))
 	router.HandleFunc("/logout", logoutHandler)