Add read-only mode support and enhance logging throughout the application

Dockerfile

@@ -9,6 +9,7 @@ FROM scratch
 
 # Group ID 20 is dialout, needed for tty read/write access
 USER 3000:20
+ENV READ_ONLY=false
 COPY --from=builder /build/invertergui /bin/
 ENTRYPOINT [ "/bin/invertergui" ]
 EXPOSE 8080

README.md

@@ -31,6 +31,7 @@ Usage:
 
 Application Options:
       --address=        The IP/DNS and port of the machine that the application is running on. (default: :8080) [$ADDRESS]
+      --read_only       Disable all write operations and run in monitoring-only mode. [$READ_ONLY]
       --data.source=    Set the source of data for the inverter gui. "serial", "tcp" or "mock" (default: serial) [$DATA_SOURCE]
       --data.host=      Host to connect when source is set to tcp. (default: localhost:8139) [$DATA_HOST]
       --data.device=    TTY device to use when source is set to serial. (default: /dev/ttyUSB0) [$DATA_DEVICE]
@@ -54,6 +55,26 @@ Help Options:
   -h, --help            Show this help message
 ```
 
+### Read-Only Mode
+
+Set `READ_ONLY=true` (or `--read_only`) to disable all write operations.
+When read-only mode is enabled, the app still monitors and publishes telemetry, but it will not send commands to the Victron device.
+
+This affects:
+
+- MQTT command handling (`--mqtt.command_topic` commands are ignored)
+- Web UI control actions (`POST /api/remote-panel/state` and `POST /api/remote-panel/standby`)
+
+Example `docker-compose.yml` snippet:
+
+```yaml
+services:
+  invertergui:
+    image: registry.coadcorp.com/nathan/invertergui:latest
+    environment:
+      READ_ONLY: "true"
+```
+
 ## Port 8080
 
 The default HTTP server port is hosted on port 8080. This exposes the HTTP server that hosts the:
@@ -315,6 +336,12 @@ The MQTT client will publish updates to the given broker at the set topic.
 --mqtt.password-file= Path to a file containing the MQTT password [$MQTT_PASSWORD_FILE]
 ```
 
+Related global option:
+
+```bash
+--read_only Disable all write operations and run in monitoring-only mode. [$READ_ONLY]
+```
+
 The MQTT client can be enabled by setting the environment variable `MQTT_ENABLED=true` or flag `--mqtt.enabled`.
 All MQTT configuration can be done via flags or as environment variables.
 The URI for the broker can be configured format should be `scheme://host:port`, where "scheme" is one of "tcp", "ssl", or "ws".

cmd/invertergui/config.go

@@ -9,8 +9,9 @@ import (
 )
 
 type config struct {
-	Address string `long:"address" env:"ADDRESS" default:":8080" description:"The IP/DNS and port of the machine that the application is running on."`
+	Address  string `long:"address" env:"ADDRESS" default:":8080" description:"The IP/DNS and port of the machine that the application is running on."`
-	Data    struct {
+	ReadOnly bool   `long:"read_only" env:"READ_ONLY" description:"Disable all write operations and run in monitoring-only mode."`
+	Data     struct {
 		Source string `long:"data.source" env:"DATA_SOURCE" default:"serial" description:"Set the source of data for the inverter gui. \"serial\", \"tcp\" or \"mock\""`
 		Host   string `long:"data.host" env:"DATA_HOST" default:"localhost:8139" description:"Host to connect when source is set to tcp."`
 		Device string `long:"data.device" env:"DATA_DEVICE" default:"/dev/ttyUSB0" description:"TTY device to use when source is set to serial."`

cmd/invertergui/main.go

@@ -55,6 +55,7 @@ var log = logrus.WithField("ctx", "inverter-gui")
 func main() {
 	conf, err := parseConfig()
 	if err != nil {
+		log.WithError(err).Error("Could not parse configuration")
 		os.Exit(1)
 	}
 	log.Info("Starting invertergui")
@@ -63,16 +64,33 @@ func main() {
 		log.Fatalf("Could not parse log level: %v", err)
 	}
 	logrus.SetLevel(logLevel)
+	log.WithFields(logrus.Fields{
+		"loglevel":           conf.Loglevel,
+		"address":            conf.Address,
+		"read_only":          conf.ReadOnly,
+		"data_source":        conf.Data.Source,
+		"data_host":          conf.Data.Host,
+		"data_device":        conf.Data.Device,
+		"cli_enabled":        conf.Cli.Enabled,
+		"mqtt_enabled":       conf.MQTT.Enabled,
+		"mqtt_broker":        conf.MQTT.Broker,
+		"mqtt_topic":         conf.MQTT.Topic,
+		"mqtt_command_topic": conf.MQTT.CommandTopic,
+		"mqtt_status_topic":  conf.MQTT.StatusTopic,
+		"mqtt_ha_enabled":    conf.MQTT.HA.Enabled,
+	}).Info("Configuration loaded")
 
 	mk2, err := getMk2Device(conf.Data.Source, conf.Data.Host, conf.Data.Device)
 	if err != nil {
 		log.Fatalf("Could not open data source: %v", err)
 	}
 	defer mk2.Close()
+	log.Info("MK2 device connection established")
 
 	core := mk2core.NewCore(mk2)
 
 	if conf.Cli.Enabled {
+		log.Info("CLI plugin enabled")
 		cli.NewCli(core.NewSubscription())
 	}
 
@@ -80,21 +98,35 @@ func main() {
 	var writer mk2driver.SettingsWriter
 	if w, ok := mk2.(mk2driver.SettingsWriter); ok {
 		writer = w
+		log.Info("MK2 data source supports settings writes")
+	} else {
+		log.Warn("MK2 data source does not support settings writes")
+	}
+	if conf.ReadOnly {
+		if writer != nil {
+			log.Warn("READ_ONLY enabled; disabling all write operations")
+		} else {
+			log.Info("READ_ONLY enabled")
+		}
+		writer = nil
 	}
 	gui := webui.NewWebGui(core.NewSubscription(), writer)
 	http.Handle("/", static.New())
 	http.Handle("/ws", http.HandlerFunc(gui.ServeHub))
 	http.Handle("/api/remote-panel/state", http.HandlerFunc(gui.ServeRemotePanelState))
 	http.Handle("/api/remote-panel/standby", http.HandlerFunc(gui.ServeRemotePanelStandby))
+	log.Info("Web UI routes registered")
 
 	// Munin
 	mu := munin.NewMunin(core.NewSubscription())
 	http.Handle("/munin", http.HandlerFunc(mu.ServeMuninHTTP))
 	http.Handle("/muninconfig", http.HandlerFunc(mu.ServeMuninConfigHTTP))
+	log.Info("Munin routes registered")
 
 	// Prometheus
 	prometheus.NewPrometheus(core.NewSubscription())
 	http.Handle("/metrics", promhttp.Handler())
+	log.Info("Prometheus route registered")
 
 	// MQTT
 	if conf.MQTT.Enabled {
@@ -119,6 +151,7 @@ func main() {
 		if err := mqttclient.New(core.NewSubscription(), writer, mqttConf); err != nil {
 			log.Fatalf("Could not setup MQTT client: %v", err)
 		}
+		log.Info("MQTT client initialized")
 	}
 	log.Infof("Invertergui web server starting on: %v", conf.Address)
 
@@ -134,12 +167,14 @@ func getMk2Device(source, ip, dev string) (mk2driver.Mk2, error) {
 
 	switch source {
 	case "serial":
+		log.WithField("device", dev).Info("Opening serial MK2 source")
 		serialConfig := &serial.Config{Name: dev, Baud: 2400}
 		p, err = serial.OpenPort(serialConfig)
 		if err != nil {
 			return nil, err
 		}
 	case "tcp":
+		log.WithField("host", ip).Info("Opening TCP MK2 source")
 		tcpAddr, err = net.ResolveTCPAddr("tcp", ip)
 		if err != nil {
 			return nil, err
@@ -149,6 +184,7 @@ func getMk2Device(source, ip, dev string) (mk2driver.Mk2, error) {
 			return nil, err
 		}
 	case "mock":
+		log.Info("Using mock MK2 data source")
 		return mk2driver.NewMk2Mock(), nil
 	default:
 		return nil, fmt.Errorf("Invalid source selection: %v\nUse \"serial\", \"tcp\" or \"mock\"", source)
@@ -158,6 +194,7 @@ func getMk2Device(source, ip, dev string) (mk2driver.Mk2, error) {
 	if err != nil {
 		return nil, err
 	}
+	log.WithField("source", source).Info("MK2 connection ready")
 
 	return mk2, nil
 }

mk2core/core.go

@@ -2,8 +2,11 @@ package mk2core
 
 import (
 	"git.coadcorp.com/nathan/invertergui/mk2driver"
+	"github.com/sirupsen/logrus"
 )
 
+var log = logrus.WithField("ctx", "inverter-gui-core")
+
 type Core struct {
 	mk2driver.Mk2
 	plugins  map[*subscription]bool
@@ -16,6 +19,7 @@ func NewCore(m mk2driver.Mk2) *Core {
 		register: make(chan *subscription, 255),
 		plugins:  map[*subscription]bool{},
 	}
+	log.Info("Core initialized")
 	go core.run()
 	return core
 }
@@ -25,6 +29,7 @@ func (c *Core) NewSubscription() mk2driver.Mk2 {
 		send: make(chan *mk2driver.Mk2Info),
 	}
 	c.register <- sub
+	log.Debug("New plugin subscription registered")
 	return sub
 }
 
@@ -33,11 +38,13 @@ func (c *Core) run() {
 		select {
 		case r := <-c.register:
 			c.plugins[r] = true
+			log.WithField("subscribers", len(c.plugins)).Debug("Subscription added")
 		case e := <-c.C():
 			for plugin := range c.plugins {
 				select {
 				case plugin.send <- e:
 				default:
+					log.WithField("subscribers", len(c.plugins)).Warn("Dropping update for a slow subscriber")
 				}
 			}
 		}

mk2driver/mk2.go

@@ -11,6 +11,8 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
+var mk2log = logrus.WithField("ctx", "inverter-gui-mk2driver")
+
 type scaling struct {
 	scale     float64
 	offset    float64
@@ -122,6 +124,7 @@ func NewMk2Connection(dev io.ReadWriter) (Mk2, error) {
 	mk2.run = make(chan struct{})
 	mk2.infochan = make(chan *Mk2Info)
 	mk2.wg.Add(1)
+	mk2log.Info("MK2 connection initialized")
 	go mk2.frameLocker()
 	return mk2, nil
 }
@@ -163,7 +166,7 @@ func (m *mk2Ser) frameLocker() {
 				} else {
 					if checkChecksum(frameLength, tmp, frame[:frameLengthOffset]) {
 						m.frameLock = true
-						logrus.Info("Locked")
+						mk2log.Info("Frame lock acquired")
 					}
 				}
 			}
@@ -174,8 +177,10 @@ func (m *mk2Ser) frameLocker() {
 
 // Close Mk2
 func (m *mk2Ser) Close() {
+	mk2log.Info("Closing MK2 connection")
 	close(m.run)
 	m.wg.Wait()
+	mk2log.Info("MK2 connection closed")
 }
 
 func (m *mk2Ser) C() chan *Mk2Info {
@@ -183,11 +188,31 @@ func (m *mk2Ser) C() chan *Mk2Info {
 }
 
 func (m *mk2Ser) WriteRAMVar(id uint16, value int16) error {
-	return m.writeByID(commandWriteRAMVar, commandWriteRAMResponse, id, value)
+	mk2log.WithFields(logrus.Fields{
+		"id":    id,
+		"value": value,
+	}).Info("WriteRAMVar requested")
+	err := m.writeByID(commandWriteRAMVar, commandWriteRAMResponse, id, value)
+	if err != nil {
+		mk2log.WithError(err).WithField("id", id).Error("WriteRAMVar failed")
+		return err
+	}
+	mk2log.WithField("id", id).Info("WriteRAMVar applied")
+	return nil
 }
 
 func (m *mk2Ser) WriteSetting(id uint16, value int16) error {
-	return m.writeByID(commandWriteSetting, commandWriteSettingResponse, id, value)
+	mk2log.WithFields(logrus.Fields{
+		"id":    id,
+		"value": value,
+	}).Info("WriteSetting requested")
+	err := m.writeByID(commandWriteSetting, commandWriteSettingResponse, id, value)
+	if err != nil {
+		mk2log.WithError(err).WithField("id", id).Error("WriteSetting failed")
+		return err
+	}
+	mk2log.WithField("id", id).Info("WriteSetting applied")
+	return nil
 }
 
 func (m *mk2Ser) SetPanelState(switchState PanelSwitchState, currentLimitA *float64) error {
@@ -203,6 +228,12 @@ func (m *mk2Ser) SetPanelState(switchState PanelSwitchState, currentLimitA *floa
 	m.commandMu.Lock()
 	defer m.commandMu.Unlock()
 
+	logEntry := mk2log.WithField("switch_state", switchState)
+	if currentLimitA != nil {
+		logEntry = logEntry.WithField("current_limit_a", *currentLimitA)
+	}
+	logEntry.Info("SetPanelState requested")
+
 	m.clearStateResponses()
 	m.sendCommandLocked([]byte{
 		stateFrame,
@@ -213,7 +244,13 @@ func (m *mk2Ser) SetPanelState(switchState PanelSwitchState, currentLimitA *floa
 		panelStateVariant2Flags,
 	})
 
-	return m.waitForStateResponse()
+	err = m.waitForStateResponse()
+	if err != nil {
+		logEntry.WithError(err).Error("SetPanelState failed")
+		return err
+	}
+	logEntry.Info("SetPanelState acknowledged")
+	return nil
 }
 
 func (m *mk2Ser) SetStandby(enabled bool) error {
@@ -224,6 +261,8 @@ func (m *mk2Ser) SetStandby(enabled bool) error {
 
 	m.commandMu.Lock()
 	defer m.commandMu.Unlock()
+	logEntry := mk2log.WithField("standby_enabled", enabled)
+	logEntry.Info("SetStandby requested")
 
 	m.clearInterfaceResponses()
 	m.sendCommandLocked([]byte{
@@ -231,7 +270,13 @@ func (m *mk2Ser) SetStandby(enabled bool) error {
 		lineState,
 	})
 
-	return m.waitForInterfaceResponse(enabled)
+	err := m.waitForInterfaceResponse(enabled)
+	if err != nil {
+		logEntry.WithError(err).Error("SetStandby failed")
+		return err
+	}
+	logEntry.Info("SetStandby acknowledged")
+	return nil
 }
 
 func validPanelSwitchState(switchState PanelSwitchState) bool {
@@ -261,6 +306,12 @@ func encodePanelCurrentLimit(currentLimitA *float64) (uint16, error) {
 func (m *mk2Ser) writeByID(selectCommand, expectedResponse byte, id uint16, value int16) error {
 	m.commandMu.Lock()
 	defer m.commandMu.Unlock()
+	mk2log.WithFields(logrus.Fields{
+		"select_command":    fmt.Sprintf("0x%02x", selectCommand),
+		"expected_response": fmt.Sprintf("0x%02x", expectedResponse),
+		"id":                id,
+		"value":             value,
+	}).Debug("Issuing write-by-id command")
 
 	m.clearWriteResponses()
 
@@ -303,6 +354,10 @@ func (m *mk2Ser) waitForWriteResponse(expectedResponse byte) error {
 
 	select {
 	case response := <-m.writeAck:
+		mk2log.WithFields(logrus.Fields{
+			"expected_response": fmt.Sprintf("0x%02x", expectedResponse),
+			"received_response": fmt.Sprintf("0x%02x", response),
+		}).Debug("Received write acknowledgement")
 		switch response {
 		case expectedResponse:
 			return nil
@@ -314,6 +369,7 @@ func (m *mk2Ser) waitForWriteResponse(expectedResponse byte) error {
 			return fmt.Errorf("unexpected write response 0x%02x", response)
 		}
 	case <-time.After(writeResponseTimeout):
+		mk2log.WithField("expected_response", fmt.Sprintf("0x%02x", expectedResponse)).Error("Timed out waiting for write acknowledgement")
 		return fmt.Errorf("timed out waiting for write response after %s", writeResponseTimeout)
 	}
 }
@@ -350,8 +406,10 @@ func (m *mk2Ser) waitForStateResponse() error {
 
 	select {
 	case <-m.stateAck:
+		mk2log.Debug("Received panel state acknowledgement")
 		return nil
 	case <-time.After(writeResponseTimeout):
+		mk2log.Error("Timed out waiting for panel state acknowledgement")
 		return fmt.Errorf("timed out waiting for panel state response after %s", writeResponseTimeout)
 	}
 }
@@ -389,11 +447,17 @@ func (m *mk2Ser) waitForInterfaceResponse(expectedStandby bool) error {
 	select {
 	case lineState := <-m.ifaceAck:
 		standbyEnabled := lineState&interfaceStandbyFlag != 0
+		mk2log.WithFields(logrus.Fields{
+			"line_state":       fmt.Sprintf("0x%02x", lineState),
+			"expected_standby": expectedStandby,
+			"actual_standby":   standbyEnabled,
+		}).Debug("Received standby interface acknowledgement")
 		if standbyEnabled != expectedStandby {
 			return fmt.Errorf("unexpected standby line state 0x%02x", lineState)
 		}
 		return nil
 	case <-time.After(writeResponseTimeout):
+		mk2log.WithField("expected_standby", expectedStandby).Error("Timed out waiting for standby acknowledgement")
 		return fmt.Errorf("timed out waiting for standby response after %s", writeResponseTimeout)
 	}
 }
@@ -421,7 +485,7 @@ func (m *mk2Ser) readByte() byte {
 
 // Adds error to error slice.
 func (m *mk2Ser) addError(err error) {
-	logrus.Errorf("Mk2 serial slice error: %q", err.Error())
+	mk2log.Errorf("Mk2 serial slice error: %q", err.Error())
 	if m.info.Errors == nil {
 		m.info.Errors = make([]error, 0)
 	}
@@ -432,16 +496,27 @@ func (m *mk2Ser) addError(err error) {
 // Updates report.
 func (m *mk2Ser) updateReport() {
 	m.info.Timestamp = time.Now()
+	mk2log.WithFields(logrus.Fields{
+		"in_voltage":   m.info.InVoltage,
+		"in_current":   m.info.InCurrent,
+		"out_voltage":  m.info.OutVoltage,
+		"out_current":  m.info.OutCurrent,
+		"bat_voltage":  m.info.BatVoltage,
+		"bat_current":  m.info.BatCurrent,
+		"charge_state": m.info.ChargeState,
+		"valid":        m.info.Valid,
+	}).Debug("Publishing MK2 status update")
 	select {
 	case m.infochan <- m.info:
 	default:
+		mk2log.Warn("Dropping MK2 status update; consumer channel is full")
 	}
 	m.info = &Mk2Info{}
 }
 
 // Checks for valid frame and chooses decoding.
 func (m *mk2Ser) handleFrame(l byte, frame []byte) {
-	logrus.Debugf("[handleFrame] frame %#v", frame)
+	mk2log.Debugf("[handleFrame] frame %#v", frame)
 	if checkChecksum(l, frame[0], frame[1:]) {
 		switch frame[0] {
 		case bootupFrameHeader:
@@ -465,13 +540,13 @@ func (m *mk2Ser) handleFrame(l byte, frame []byte) {
 				case commandWriteRAMResponse, commandWriteSettingResponse, commandUnsupportedResponse, commandWriteNotAllowedResponse:
 					m.pushWriteResponse(frame[2])
 				default:
-					logrus.Warnf("[handleFrame] invalid winmonFrame %v", frame[2:])
+					mk2log.Warnf("[handleFrame] invalid winmonFrame %v", frame[2:])
 				}
 
 			case ledFrame:
 				m.ledDecode(frame[2:])
 			default:
-				logrus.Warnf("[handleFrame] invalid frameHeader %v", frame[1])
+				mk2log.Warnf("[handleFrame] invalid frameHeader %v", frame[1])
 			}
 
 		case infoFrameHeader:
@@ -481,13 +556,13 @@ func (m *mk2Ser) handleFrame(l byte, frame []byte) {
 			case acL1InfoFrame:
 				m.acDecode(frame[1:])
 			default:
-				logrus.Warnf("[handleFrame] invalid infoFrameHeader %v", frame[5])
+				mk2log.Warnf("[handleFrame] invalid infoFrameHeader %v", frame[5])
 			}
 		default:
-			logrus.Warnf("[handleFrame] Invalid frame %v", frame[0])
+			mk2log.Warnf("[handleFrame] Invalid frame %v", frame[0])
 		}
 	} else {
-		logrus.Errorf("[handleFrame] Invalid incoming frame checksum: %x", frame)
+		mk2log.Errorf("[handleFrame] Invalid incoming frame checksum: %x", frame)
 		m.frameLock = false
 	}
 }
@@ -520,10 +595,10 @@ func int16Abs(in int16) uint16 {
 // Decode the scale factor frame.
 func (m *mk2Ser) scaleDecode(frame []byte) {
 	tmp := scaling{}
-	logrus.Debugf("Scale frame(%d): 0x%x", len(frame), frame)
+	mk2log.Debugf("Scale frame(%d): 0x%x", len(frame), frame)
 	if len(frame) < 6 {
 		tmp.supported = false
-		logrus.Warnf("Skiping scaling factors for: %d", m.scaleCount)
+		mk2log.Warnf("Skiping scaling factors for: %d", m.scaleCount)
 	} else {
 		tmp.supported = true
 		var scl int16
@@ -546,19 +621,19 @@ func (m *mk2Ser) scaleDecode(frame []byte) {
 			tmp.scale = float64(scale)
 		}
 	}
-	logrus.Debugf("scalecount %v: %#v \n", m.scaleCount, tmp)
+	mk2log.Debugf("scalecount %v: %#v \n", m.scaleCount, tmp)
 	m.scales = append(m.scales, tmp)
 	m.scaleCount++
 	if m.scaleCount < ramVarMaxOffset {
 		m.reqScaleFactor(byte(m.scaleCount))
 	} else {
-		logrus.Info("Monitoring starting.")
+		mk2log.Info("Monitoring starting.")
 	}
 }
 
 // Decode the version number
 func (m *mk2Ser) versionDecode(frame []byte) {
-	logrus.Debugf("versiondecode %v", frame)
+	mk2log.Debugf("versiondecode %v", frame)
 	m.info.Version = 0
 	m.info.Valid = true
 	for i := 0; i < 4; i++ {
@@ -566,7 +641,7 @@ func (m *mk2Ser) versionDecode(frame []byte) {
 	}
 
 	if m.scaleCount < ramVarMaxOffset {
-		logrus.Info("Get scaling factors.")
+		mk2log.WithField("version", m.info.Version).Info("Get scaling factors")
 		m.reqScaleFactor(byte(m.scaleCount))
 	} else {
 		// Send DC status request
@@ -623,7 +698,7 @@ func (m *mk2Ser) dcDecode(frame []byte) {
 	m.info.BatCurrent = usedC - chargeC
 
 	m.info.OutFrequency = m.calcFreq(frame[13], ramVarInverterPeriod)
-	logrus.Debugf("dcDecode %#v", m.info)
+	mk2log.Debugf("dcDecode %#v", m.info)
 
 	// Send L1 status request
 	cmd := make([]byte, 2)
@@ -640,7 +715,7 @@ func (m *mk2Ser) acDecode(frame []byte) {
 	m.info.OutCurrent = m.applyScale(getSigned(frame[11:13]), ramVarIInverter)
 	m.info.InFrequency = m.calcFreq(frame[13], ramVarMainPeriod)
 
-	logrus.Debugf("acDecode %#v", m.info)
+	mk2log.Debugf("acDecode %#v", m.info)
 
 	// Send status request
 	cmd := make([]byte, 1)
@@ -658,7 +733,7 @@ func (m *mk2Ser) calcFreq(data byte, scaleIndex int) float64 {
 // Decode charge state of battery.
 func (m *mk2Ser) stateDecode(frame []byte) {
 	m.info.ChargeState = m.applyScaleAndSign(frame[1:3], ramVarChargeState)
-	logrus.Debugf("battery state decode %#v", m.info)
+	mk2log.Debugf("battery state decode %#v", m.info)
 	m.updateReport()
 }
 
@@ -711,9 +786,10 @@ func (m *mk2Ser) sendCommandLocked(data []byte) {
 	}
 	dataOut[l+2] = cr
 
-	logrus.Debugf("sendCommand %#v", dataOut)
+	mk2log.Debugf("sendCommand %#v", dataOut)
 	_, err := m.p.Write(dataOut)
 	if err != nil {
+		mk2log.WithError(err).Error("Failed to send MK2 command")
 		m.addError(fmt.Errorf("Write error: %v", err))
 	}
 }

plugins/mqttclient/mqtt.go

@@ -99,6 +99,17 @@ type panelStateCache struct {
 
 // New creates an MQTT client that publishes MK2 updates and optionally handles setting write commands.
 func New(mk2 mk2driver.Mk2, writer mk2driver.SettingsWriter, config Config) error {
+	log.WithFields(logrus.Fields{
+		"broker":         config.Broker,
+		"client_id":      config.ClientID,
+		"topic":          config.Topic,
+		"command_topic":  config.CommandTopic,
+		"status_topic":   config.StatusTopic,
+		"ha_enabled":     config.HomeAssistant.Enabled,
+		"ha_node_id":     config.HomeAssistant.NodeID,
+		"ha_device_name": config.HomeAssistant.DeviceName,
+	}).Info("Initializing MQTT client")
+
 	c := mqtt.NewClient(getOpts(config))
 	if token := c.Connect(); token.Wait() && token.Error() != nil {
 		return token.Error()
@@ -135,14 +146,18 @@ func New(mk2 mk2driver.Mk2, writer mk2driver.SettingsWriter, config Config) erro
 	go func() {
 		for e := range mk2.C() {
 			if e == nil || !e.Valid {
+				log.Debug("Skipping invalid/nil MK2 event for MQTT publish")
 				continue
 			}
 			if err := publishJSON(c, config.Topic, e, 0, false); err != nil {
 				log.Errorf("Could not publish update to MQTT topic %q: %v", config.Topic, err)
+			} else {
+				log.WithField("topic", config.Topic).Debug("Published MK2 update to MQTT")
 			}
 		}
 	}()
 
+	log.Info("MQTT client setup complete")
 	return nil
 }
 
@@ -152,9 +167,14 @@ func subscribeHAPanelModeState(client mqtt.Client, config Config, cache *panelSt
 	}
 
 	stateTopic := haPanelSwitchStateTopic(config)
+	log.WithField("topic", stateTopic).Info("Subscribing to Home Assistant mode state topic for panel cache")
 	t := client.Subscribe(stateTopic, 1, func(_ mqtt.Client, msg mqtt.Message) {
 		switchState, switchName, err := normalizePanelSwitch(string(msg.Payload()))
 		if err != nil {
+			log.WithFields(logrus.Fields{
+				"topic":   msg.Topic(),
+				"payload": string(msg.Payload()),
+			}).WithError(err).Warn("Ignoring invalid Home Assistant mode state payload")
 			return
 		}
 		cache.remember(writeCommand{
@@ -163,6 +183,10 @@ func subscribeHAPanelModeState(client mqtt.Client, config Config, cache *panelSt
 			SwitchState: switchState,
 			SwitchName:  switchName,
 		})
+		log.WithFields(logrus.Fields{
+			"topic":       msg.Topic(),
+			"switch_name": switchName,
+		}).Debug("Updated panel mode cache from Home Assistant state topic")
 	})
 	t.Wait()
 	return t.Error()
@@ -174,6 +198,11 @@ func commandHandler(client mqtt.Client, writer mk2driver.SettingsWriter, config
 	}
 
 	return func(_ mqtt.Client, msg mqtt.Message) {
+		log.WithFields(logrus.Fields{
+			"topic":   msg.Topic(),
+			"payload": string(msg.Payload()),
+		}).Debug("Received MQTT command message")
+
 		cmd, err := decodeWriteCommand(msg.Payload())
 		if err != nil {
 			log.Errorf("Invalid MQTT write command payload from topic %q: %v", msg.Topic(), err)
@@ -247,6 +276,7 @@ func (c *panelStateCache) resolvePanelCommand(cmd writeCommand) (writeCommand, e
 	cmd.HasSwitch = true
 	cmd.SwitchName = c.switchName
 	cmd.SwitchState = c.switchState
+	log.WithField("switch", cmd.SwitchName).Debug("Resolved panel command switch from cache")
 	return cmd, nil
 }
 
@@ -260,6 +290,7 @@ func (c *panelStateCache) remember(cmd writeCommand) {
 	c.switchName = cmd.SwitchName
 	c.switchState = cmd.SwitchState
 	c.mu.Unlock()
+	log.WithField("switch", cmd.SwitchName).Debug("Remembered panel switch state in cache")
 }
 
 func decodeWriteCommand(payload []byte) (writeCommand, error) {
@@ -465,6 +496,7 @@ func decodeStandbyValue(msg writeCommandPayload) (bool, error) {
 
 func publishWriteStatus(client mqtt.Client, topic string, status writeStatus) {
 	if topic == "" {
+		log.Debug("Skipping write status publish; status topic is empty")
 		return
 	}
 	if err := publishJSON(client, topic, status, 1, false); err != nil {
@@ -479,6 +511,11 @@ func publishHADiscovery(client mqtt.Client, config Config) error {
 
 	for _, def := range definitions {
 		topic := fmt.Sprintf("%s/%s/%s/%s/config", prefix, def.Component, nodeID, def.ObjectID)
+		log.WithFields(logrus.Fields{
+			"topic":     topic,
+			"component": def.Component,
+			"object_id": def.ObjectID,
+		}).Debug("Publishing Home Assistant discovery definition")
 		if err := publishJSON(client, topic, def.Config, 1, true); err != nil {
 			return fmt.Errorf("could not publish discovery for %s/%s: %w", def.Component, def.ObjectID, err)
 		}
@@ -665,6 +702,12 @@ func publishJSON(client mqtt.Client, topic string, payload any, qos byte, retain
 	if t.Error() != nil {
 		return t.Error()
 	}
+	log.WithFields(logrus.Fields{
+		"topic":    topic,
+		"qos":      qos,
+		"retained": retained,
+		"bytes":    len(data),
+	}).Debug("Published JSON message")
 
 	return nil
 }
@@ -679,6 +722,12 @@ func publishString(client mqtt.Client, topic, payload string, qos byte, retained
 	if t.Error() != nil {
 		return t.Error()
 	}
+	log.WithFields(logrus.Fields{
+		"topic":    topic,
+		"qos":      qos,
+		"retained": retained,
+		"payload":  payload,
+	}).Debug("Published string message")
 	return nil
 }
 

plugins/webui/webgui.go

@@ -85,6 +85,7 @@ func NewWebGui(source mk2driver.Mk2, writer mk2driver.SettingsWriter) *WebGui {
 			Mode:     modeUnknown,
 		},
 	}
+	log.WithField("remote_writable", writer != nil).Info("Web UI initialized")
 	w.wg.Add(1)
 	go w.dataPoll()
 	return w
@@ -138,50 +139,77 @@ type setRemotePanelStandbyRequest struct {
 }
 
 func (w *WebGui) ServeHub(rw http.ResponseWriter, r *http.Request) {
+	log.WithFields(logrus.Fields{
+		"remote": r.RemoteAddr,
+		"path":   r.URL.Path,
+	}).Debug("WebSocket hub request")
 	w.hub.ServeHTTP(rw, r)
 }
 
 func (w *WebGui) ServeRemotePanelState(rw http.ResponseWriter, r *http.Request) {
+	log.WithFields(logrus.Fields{
+		"method": r.Method,
+		"path":   r.URL.Path,
+		"remote": r.RemoteAddr,
+	}).Debug("Remote panel state API request")
+
 	switch r.Method {
 	case http.MethodGet:
 		writeJSON(rw, http.StatusOK, w.getRemotePanelState())
 	case http.MethodPost:
 		w.handleSetRemotePanelState(rw, r)
 	default:
+		log.WithField("method", r.Method).Warn("Remote panel state API received unsupported method")
 		http.Error(rw, "method not allowed", http.StatusMethodNotAllowed)
 	}
 }
 
 func (w *WebGui) ServeRemotePanelStandby(rw http.ResponseWriter, r *http.Request) {
+	log.WithFields(logrus.Fields{
+		"method": r.Method,
+		"path":   r.URL.Path,
+		"remote": r.RemoteAddr,
+	}).Debug("Remote panel standby API request")
+
 	switch r.Method {
 	case http.MethodGet:
 		writeJSON(rw, http.StatusOK, w.getRemotePanelState())
 	case http.MethodPost:
 		w.handleSetRemotePanelStandby(rw, r)
 	default:
+		log.WithField("method", r.Method).Warn("Remote panel standby API received unsupported method")
 		http.Error(rw, "method not allowed", http.StatusMethodNotAllowed)
 	}
 }
 
 func (w *WebGui) handleSetRemotePanelState(rw http.ResponseWriter, r *http.Request) {
 	if w.writer == nil {
+		log.Warn("Remote panel state write requested, but writer is unavailable")
 		http.Error(rw, "remote control is not supported by this data source", http.StatusNotImplemented)
 		return
 	}
 
 	req := setRemotePanelStateRequest{}
 	if err := decodeJSONBody(r, &req); err != nil {
+		log.WithError(err).Warn("Invalid remote panel state request body")
 		http.Error(rw, err.Error(), http.StatusBadRequest)
 		return
 	}
+	logEntry := log.WithField("mode", req.Mode)
+	if req.CurrentLimit != nil {
+		logEntry = logEntry.WithField("current_limit_a", *req.CurrentLimit)
+	}
+	logEntry.Info("Applying remote panel state from API")
 
 	switchState, normalizedMode, err := parsePanelMode(req.Mode)
 	if err != nil {
+		logEntry.WithError(err).Warn("Unsupported remote panel mode")
 		http.Error(rw, err.Error(), http.StatusBadRequest)
 		return
 	}
 
 	if err := w.writer.SetPanelState(switchState, req.CurrentLimit); err != nil {
+		logEntry.WithError(err).Error("Failed to apply remote panel state")
 		w.updateRemotePanelState(func(state *remotePanelState) {
 			state.LastCommand = "set_remote_panel_state"
 			state.LastError = err.Error()
@@ -196,22 +224,27 @@ func (w *WebGui) handleSetRemotePanelState(rw http.ResponseWriter, r *http.Reque
 		state.LastCommand = "set_remote_panel_state"
 		state.LastError = ""
 	})
+	logEntry.WithField("normalized_mode", normalizedMode).Info("Remote panel state applied")
 	writeJSON(rw, http.StatusOK, w.getRemotePanelState())
 }
 
 func (w *WebGui) handleSetRemotePanelStandby(rw http.ResponseWriter, r *http.Request) {
 	if w.writer == nil {
+		log.Warn("Remote panel standby write requested, but writer is unavailable")
 		http.Error(rw, "remote control is not supported by this data source", http.StatusNotImplemented)
 		return
 	}
 
 	req := setRemotePanelStandbyRequest{}
 	if err := decodeJSONBody(r, &req); err != nil {
+		log.WithError(err).Warn("Invalid remote panel standby request body")
 		http.Error(rw, err.Error(), http.StatusBadRequest)
 		return
 	}
+	log.WithField("standby", req.Standby).Info("Applying standby state from API")
 
 	if err := w.writer.SetStandby(req.Standby); err != nil {
+		log.WithError(err).WithField("standby", req.Standby).Error("Failed to apply standby state")
 		w.updateRemotePanelState(func(state *remotePanelState) {
 			state.LastCommand = "set_remote_panel_standby"
 			state.LastError = err.Error()
@@ -225,6 +258,7 @@ func (w *WebGui) handleSetRemotePanelStandby(rw http.ResponseWriter, r *http.Req
 		state.LastCommand = "set_remote_panel_standby"
 		state.LastError = ""
 	})
+	log.WithField("standby", req.Standby).Info("Standby state applied")
 	writeJSON(rw, http.StatusOK, w.getRemotePanelState())
 }
 
@@ -301,23 +335,32 @@ func buildTemplateInput(status *mk2driver.Mk2Info) *templateInput {
 }
 
 func (w *WebGui) Stop() {
+	log.Info("Stopping Web UI polling")
 	close(w.stopChan)
 	w.wg.Wait()
+	log.Info("Web UI polling stopped")
 }
 
 func (w *WebGui) dataPoll() {
 	for {
 		select {
 		case s := <-w.C():
-			if s.Valid {
+			if s == nil {
-				payload := buildTemplateInput(s)
+				log.Debug("Skipping nil MK2 update in Web UI poller")
-				w.stateMu.Lock()
+				continue
-				payload.RemotePanel = w.remote
+			}
-				w.latest = payload
+			if !s.Valid {
-				w.stateMu.Unlock()
+				log.WithField("errors", len(s.Errors)).Debug("Skipping invalid MK2 update in Web UI poller")
-				if err := w.hub.Broadcast(payload); err != nil {
+				continue
-					log.Errorf("Could not send update to clients: %v", err)
+			}
-				}
+
+			payload := buildTemplateInput(s)
+			w.stateMu.Lock()
+			payload.RemotePanel = w.remote
+			w.latest = payload
+			w.stateMu.Unlock()
+			if err := w.hub.Broadcast(payload); err != nil {
+				log.Errorf("Could not send update to clients: %v", err)
 			}
 		case <-w.stopChan:
 			w.wg.Done()
@@ -336,6 +379,13 @@ func (w *WebGui) updateRemotePanelState(update func(state *remotePanelState)) {
 	w.stateMu.Lock()
 	update(&w.remote)
 	w.remote.LastUpdated = time.Now().UTC().Format(time.RFC3339)
+	log.WithFields(logrus.Fields{
+		"mode":         w.remote.Mode,
+		"has_limit":    w.remote.CurrentLimit != nil,
+		"has_standby":  w.remote.Standby != nil,
+		"last_command": w.remote.LastCommand,
+		"last_error":   w.remote.LastError,
+	}).Debug("Updated remote panel state cache")
 	snapshot := w.snapshotLocked()
 	w.stateMu.Unlock()