Base project

.gitignore

@@ -0,0 +1 @@
+.env

cmd/MQTTLogger/main.go

@@ -0,0 +1,45 @@
+package main
+
+import (
+	"MQTTLogger/config"
+	"MQTTLogger/internal/csv"
+	"MQTTLogger/internal/mqtt"
+
+	"go.uber.org/fx"
+	"go.uber.org/zap"
+)
+
+func main() {
+	fx.New(
+		fx.Provide(
+			NewLogger,
+			config.NewConfig,
+			mqtt.NewClient,
+			csv.NewHelper,
+		),
+		fx.Invoke(
+			csv.InitializeHeader,
+			mqtt.SetupMQTTLogging,
+			mqtt.StartListening,
+		),
+		fx.Logger(NewFXLogger()),
+	).Run()
+}
+
+func NewLogger() (*zap.Logger, error) {
+	return zap.NewDevelopment()
+}
+
+// Simple logger for fx
+type FXLogger struct {
+	logger *zap.Logger
+}
+
+func NewFXLogger() *FXLogger {
+	logger, _ := zap.NewDevelopment()
+	return &FXLogger{logger: logger}
+}
+
+func (l *FXLogger) Printf(str string, args ...any) {
+	l.logger.Sugar().Infof(str, args...)
+}

config/config.go

@@ -0,0 +1,50 @@
+package config
+
+import (
+	"os"
+
+	"github.com/joho/godotenv"
+	"go.uber.org/zap"
+)
+
+type Config struct {
+	URI      string
+	Username string
+	Password string
+	Topics   []string
+}
+
+func NewConfig(logger *zap.Logger) *Config {
+	err := godotenv.Load()
+	if err != nil {
+		logger.Warn("Error loading .env file, using environment variables")
+	}
+
+	uri := os.Getenv("MQTT_URI")
+	if uri == "" {
+		logger.Fatal("MQTT_URI is not set")
+	}
+
+	username := os.Getenv("MQTT_USERNAME")
+	if username == "" {
+		logger.Warn("MQTT_USERNAME is not set")
+	}
+
+	password := os.Getenv("MQTT_PASSWORD")
+	if password == "" {
+		logger.Warn("MQTT_PASSWORD is not set")
+	}
+
+	topics := os.Getenv("MQTT_TOPICS")
+	if topics == "" {
+		logger.Warn("MQTT_TOPICS is not set, defaulting to #")
+		topics = "#"
+	}
+
+	return &Config{
+		URI:      uri,
+		Username: username,
+		Password: password,
+		Topics:   []string{topics},
+	}
+}

go.mod

@@ -0,0 +1,16 @@
+module MQTTLogger
+
+go 1.25.1
+
+require (
+	github.com/eclipse/paho.mqtt.golang v1.5.1 // indirect
+	github.com/gorilla/websocket v1.5.3 // indirect
+	github.com/joho/godotenv v1.5.1 // indirect
+	go.uber.org/dig v1.19.0 // indirect
+	go.uber.org/fx v1.24.0 // indirect
+	go.uber.org/multierr v1.11.0 // indirect
+	go.uber.org/zap v1.27.0 // indirect
+	golang.org/x/net v0.44.0 // indirect
+	golang.org/x/sync v0.17.0 // indirect
+	golang.org/x/sys v0.36.0 // indirect
+)

go.sum

@@ -0,0 +1,24 @@
+github.com/eclipse/paho.mqtt.golang v1.5.1 h1:/VSOv3oDLlpqR2Epjn1Q7b2bSTplJIeV2ISgCl2W7nE=
+github.com/eclipse/paho.mqtt.golang v1.5.1/go.mod h1:1/yJCneuyOoCOzKSsOTUc0AJfpsItBGWvYpBLimhArU=
+github.com/gorilla/websocket v1.5.3 h1:saDtZ6Pbx/0u+bgYQ3q96pZgCzfhKXGPqt7kZ72aNNg=
+github.com/gorilla/websocket v1.5.3/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
+github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
+github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=
+go.uber.org/dig v1.19.0 h1:BACLhebsYdpQ7IROQ1AGPjrXcP5dF80U3gKoFzbaq/4=
+go.uber.org/dig v1.19.0/go.mod h1:Us0rSJiThwCv2GteUN0Q7OKvU7n5J4dxZ9JKUXozFdE=
+go.uber.org/fx v1.24.0 h1:wE8mruvpg2kiiL1Vqd0CC+tr0/24XIB10Iwp2lLWzkg=
+go.uber.org/fx v1.24.0/go.mod h1:AmDeGyS+ZARGKM4tlH4FY2Jr63VjbEDJHtqXTGP5hbo=
+go.uber.org/multierr v1.10.0 h1:S0h4aNzvfcFsC3dRF1jLoaov7oRaKqRGC/pUEJ2yvPQ=
+go.uber.org/multierr v1.10.0/go.mod h1:20+QtiLqy0Nd6FdQB9TLXag12DsQkrbs3htMFfDN80Y=
+go.uber.org/multierr v1.11.0 h1:blXXJkSxSSfBVBlC76pxqeO+LN3aDfLQo+309xJstO0=
+go.uber.org/multierr v1.11.0/go.mod h1:20+QtiLqy0Nd6FdQB9TLXag12DsQkrbs3htMFfDN80Y=
+go.uber.org/zap v1.26.0 h1:sI7k6L95XOKS281NhVKOFCUNIvv9e0w4BF8N3u+tCRo=
+go.uber.org/zap v1.26.0/go.mod h1:dtElttAiwGvoJ/vj4IwHBS/gXsEu/pZ50mUIRWuG0so=
+go.uber.org/zap v1.27.0 h1:aJMhYGrd5QSmlpLMr2MftRKl7t8J8PTZPA732ud/XR8=
+go.uber.org/zap v1.27.0/go.mod h1:GB2qFLM7cTU87MWRP2mPIjqfIDnGu+VIO4V/SdhGo2E=
+golang.org/x/net v0.44.0 h1:evd8IRDyfNBMBTTY5XRF1vaZlD+EmWx6x8PkhR04H/I=
+golang.org/x/net v0.44.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
+golang.org/x/sync v0.17.0 h1:l60nONMj9l5drqw6jlhIELNv9I0A4OFgRsG9k2oT9Ug=
+golang.org/x/sync v0.17.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
+golang.org/x/sys v0.36.0 h1:KVRy2GtZBrk1cBYA7MKu5bEZFxQk4NIDV6RLVcC8o0k=
+golang.org/x/sys v0.36.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=

internal/csv/helper.go

@@ -0,0 +1,54 @@
+package csv
+
+import (
+	"encoding/csv"
+	"os"
+
+	"go.uber.org/fx"
+	"go.uber.org/zap"
+)
+
+type Helper struct {
+	fx.In
+	csvFile   *os.File
+	csvWriter *csv.Writer
+	logger    *zap.Logger
+}
+
+func NewHelper(lc fx.Lifecycle, logger *zap.Logger) *Helper {
+	csvFile, err := os.OpenFile("mqtt-logs.csv", os.O_CREATE|os.O_RDWR|os.O_APPEND, 0644)
+	if err != nil {
+		logger.Fatal("error opening csv file", zap.Error(err))
+	}
+
+	csvWriter := csv.NewWriter(csvFile)
+
+	return &Helper{
+		csvFile:   csvFile,
+		csvWriter: csvWriter,
+		logger:    logger,
+	}
+}
+
+func (h *Helper) AddEntry(date string, topic string, message string) error {
+	record := []string{date, topic, message}
+	if err := h.csvWriter.Write(record); err != nil {
+		h.logger.Error("error writing to csv file", zap.Error(err))
+		return err
+	}
+
+	h.csvWriter.Flush()
+
+	return nil
+}
+
+func (h *Helper) Close() error {
+	h.csvWriter.Flush()
+
+	if err := h.csvFile.Close(); err != nil {
+		h.logger.Error("error closing csv file", zap.Error(err))
+		return err
+	}
+
+	return nil
+}

internal/csv/init.go

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+package csv
+
+import (
+	"encoding/csv"
+	"io"
+	"os"
+
+	"go.uber.org/zap"
+)
+
+func InitializeHeader(logger *zap.Logger) {
+	csvFile, err := os.OpenFile("mqtt-logs.csv", os.O_CREATE|os.O_RDWR|os.O_APPEND, 0644)
+	if err != nil {
+		logger.Fatal("error opening csv file", zap.Error(err))
+	}
+	defer csvFile.Close()
+
+	r := csv.NewReader(csvFile)
+	w := csv.NewWriter(csvFile)
+	record, err := r.Read()
+
+	if err == io.EOF {
+		w.Write([]string{"Date (UTC)", "Topic", "Message"})
+		w.Flush()
+	} else if err != nil {
+		logger.Fatal("error initializing csv file", zap.Error(err))
+	} else if record[0] == "Date (UTC)" && record[1] == "Topic" && record[2] == "Message" {
+		return
+	} else {
+		logger.Fatal("First row of csv file is not as expected. Please make sure the file is in the correct format.")
+	}
+
+}

internal/mqtt/logger.go

@@ -0,0 +1,24 @@
+package mqtt
+
+import (
+	"log"
+	"strings"
+
+	mqtt "github.com/eclipse/paho.mqtt.golang"
+	"go.uber.org/zap"
+)
+
+type ZapWriter struct {
+    sugar *zap.SugaredLogger
+}
+
+func (z *ZapWriter) Write(p []byte) (n int, err error) {
+    z.sugar.Debug(strings.TrimSpace(string(p)))
+    return len(p), nil
+}
+
+func SetupMQTTLogging(logger *zap.Logger) {
+    sugar := logger.Sugar()
+    mqtt.DEBUG = log.New(&ZapWriter{sugar: sugar}, "[DEBUG] ", 0)
+    mqtt.ERROR = log.New(&ZapWriter{sugar: sugar}, "[ERROR] ", 0)
+}

internal/mqtt/mqtt.go

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+package mqtt
+
+import (
+	"MQTTLogger/config"
+	"MQTTLogger/internal/csv"
+	"time"
+
+	mqtt "github.com/eclipse/paho.mqtt.golang"
+	"go.uber.org/zap"
+)
+
+func NewClient(logger *zap.Logger, config *config.Config, csvHelper *csv.Helper) mqtt.Client {
+	var f mqtt.MessageHandler = func(client mqtt.Client, msg mqtt.Message) {
+		csvHelper.AddEntry(time.Now().UTC().Format("2006-01-02 15:04:05"), msg.Topic(), string(msg.Payload()))
+	}
+
+	opts := mqtt.NewClientOptions().AddBroker(config.URI).SetClientID("mqtt-logger")
+	opts.SetKeepAlive(2 * time.Second)
+	opts.SetDefaultPublishHandler(f)
+	opts.SetPingTimeout(1 * time.Second)
+	opts.SetConnectionNotificationHandler(func(client mqtt.Client, notification mqtt.ConnectionNotification) {
+		switch n := notification.(type) {
+		case mqtt.ConnectionNotificationConnected:
+			logger.Info("Connected to MQTT broker")
+		case mqtt.ConnectionNotificationConnecting:
+			logger.Info("connecting", zap.Bool("isReconnect", n.IsReconnect), zap.Int("attempt", n.Attempt))
+		case mqtt.ConnectionNotificationFailed:
+			logger.Error("connection failed", zap.String("error", n.Reason.Error()))
+		case mqtt.ConnectionNotificationLost:
+			logger.Error("connection lost", zap.String("error", n.Reason.Error()))
+		case mqtt.ConnectionNotificationBroker:
+			logger.Info("broker", zap.String("name", n.Broker.String()))
+		case mqtt.ConnectionNotificationBrokerFailed:
+			logger.Error("broker failed", zap.String("broker", n.Broker.String()), zap.String("error", n.Reason.Error()))
+		}
+	})
+
+	c := mqtt.NewClient(opts)
+	if token := c.Connect(); token.Wait() && token.Error() != nil {
+		logger.Fatal("error connecting to MQTT broker", zap.Error(token.Error()))
+	}
+
+	return c
+}
+
+func StartListening(logger *zap.Logger, config *config.Config, client mqtt.Client) {
+	for _, topic := range config.Topics {
+		if token := client.Subscribe(topic, 0, nil); token.Wait() && token.Error() != nil {
+			logger.Error("error subscribing to topic", zap.String("topic", topic), zap.Error(token.Error()))
+		}
+	}
+}