updated and tested till end of lesson 4

2026-10-11 15:00:58 +03:30
parent d73090946b
commit 2d639d78eb
18 changed files with 1120 additions and 187 deletions
@@ -2,16 +2,16 @@ package main

 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"log"
-	"net/url"
 	"os"
 	"os/signal"
 	"syscall"
 	"time"

-	"github.com/eclipse/paho.golang/autopaho"
-	"github.com/eclipse/paho.golang/paho"
+	"example.com/mqtt5-learning/internal/config"
+	"example.com/mqtt5-learning/internal/mqtt"
 )

 func main() {
@@ -21,71 +21,52 @@ func main() {
 }

 func run() error {
+	cfg, err := config.Load(os.Args[1:])
+	if err != nil {
+		return fmt.Errorf("failed to load config: %w", err)
+	}
+
 	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
 	defer stop()

-	user := os.Getenv("TEST_MQTT5_MQTT_USERNAME")
-	pass := os.Getenv("TEST_MQTT5_MQTT_PASSWORD")
+	base := "lab/v1/devices/" + cfg.MQTT.DeviceID
+	inbox := make(chan mqtt.Message, 16)

-	if user == "" || pass == "" {
-		return fmt.Errorf("TEST_MQTT5_MQTT_USERNAME and TEST_MQTT5_MQTT_PASSWORD environment variables not set")
-	}
-
-	broker, err := url.Parse("mqtt://127.0.0.1:18883")
+	manager, err := mqtt.Start(ctx, cfg, []string{base + "/telemetry", base + "/responses"}, inbox)
 	if err != nil {
-		return fmt.Errorf("failed to parse broker url: %w", err)
+		return fmt.Errorf("failed to start MQTT client: %w", err)
 	}
+	defer mqtt.Stop(manager)

-	cfg := autopaho.ClientConfig{
-		ServerUrls:                    []*url.URL{broker},
-		KeepAlive:                     20,
-		CleanStartOnInitialConnection: true,
-		SessionExpiryInterval:         0,
-		ConnectUsername:               user,
-		ConnectPassword:               []byte(pass),
-		OnConnectionUp: func(_ *autopaho.ConnectionManager, ack *paho.Connack) {
-			log.Printf("connected: session_present=%t reason=0x%02x", ack.SessionPresent, ack.ReasonCode)
-		},
-		OnConnectionDown: func() bool {
-			log.Print("connection down; AutoPaho will retry")
-			return true
-		},
-		OnConnectError: func(err error) {
-			log.Printf("connect attempt failed: %v", err)
-		},
-		ClientID: "lab-backend",
-		OnClientError: func(err error) {
-			log.Printf("client error: %v", err)
-		},
-		OnServerDisconnect: func(packet *paho.Disconnect) {
-			log.Printf("server disconnected: reason=0x%02x", packet.ReasonCode)
-		},
-	}
+	ticker := time.NewTicker(10 * time.Second)
+	defer ticker.Stop()

-	manager, err := autopaho.NewConnection(ctx, cfg)
-	if err != nil {
-		return fmt.Errorf("failed to create connection manager: %w", err)
-	}
+	runID := time.Now().UnixNano()
+	sequence := 0

-	defer func() {
-		shutdownCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
-		defer cancel()
-		if err := manager.Disconnect(shutdownCtx); err != nil {
-			log.Printf("shutdown did not finish within deadline: %v", err)
+	for {
+		select {
+		case <-ctx.Done():
+			log.Print("shutting down")
+			return nil
+		case msg := <-inbox:
+			log.Printf("received message on topic %s retained=%t payload=%s", msg.Topic, msg.Retain, string(msg.Payload))
+
+		case <-ticker.C:
+			sequence++
+			payload, err := json.Marshal(struct {
+				ID      string `json:"id"`
+				Command string `json:"command"`
+			}{
+				ID: fmt.Sprintf("ping-%d-%d", runID, sequence), Command: "ping",
+			})
+			if err != nil {
+				return fmt.Errorf("failed to marshal payload: %w", err)
+			}
+			if err := mqtt.Publish(ctx, manager, base+"/commands", payload); err != nil {
+				log.Printf("command publication failed or outcome uncertain: %v", err)
+			}
 		}
-	}()
-
-	startup, cancel := context.WithTimeout(ctx, 10*time.Second)
-	err = manager.AwaitConnection(startup)
-	cancel()
-
-	if err != nil {
-		return fmt.Errorf("failed to connect to broker: %w", err)
 	}

-	log.Print("connected to broker; pres Ctrl+C to stop")
-
-	<-ctx.Done()
-
-	return nil
 }
@@ -0,0 +1,18 @@
+package main
+
+import (
+	"log"
+	"os"
+
+	"example.com/mqtt5-learning/internal/config"
+)
+
+func main() {
+	cfg, err := config.Load(os.Args[1:])
+	if err != nil {
+		log.Print(err)
+		os.Exit(1)
+	}
+	log.Printf("client_id=%s device_id=%s username=%s timeout=%s password=[redacted]",
+		cfg.MQTT.ClientID, cfg.MQTT.DeviceID, cfg.MQTT.Username, cfg.ConnectTimeout())
+}
@@ -0,0 +1,87 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"log"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"example.com/mqtt5-learning/internal/config"
+	mqtt "example.com/mqtt5-learning/internal/mqtt"
+)
+
+func main() {
+	// Convert a returned application error into a visible nonzero process exit.
+	if err := run(); err != nil {
+		log.Print(err)
+		os.Exit(1)
+	}
+}
+
+func run() error {
+	// Load settings and bind cancellation to Ctrl+C or the container stop signal.
+	cfg, err := config.Load(os.Args[1:])
+	if err != nil {
+		return err
+	}
+	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
+	defer stop()
+	// Build this device's topic namespace and bounded receive queue.
+	base := "lab/v1/devices/" + cfg.MQTT.DeviceID
+	inbox := make(chan mqtt.Message, 16)
+	manager, err := mqtt.Start(ctx, cfg, []string{base + "/commands"}, inbox)
+	if err != nil {
+		return err
+	}
+	defer mqtt.Stop(manager)
+	// Heartbeats are periodic; command handling remains active between ticks.
+	ticker := time.NewTicker(3 * time.Second)
+	defer ticker.Stop()
+	for {
+		// Handle cancellation, telemetry publication, and inbound commands together.
+		select {
+		case <-ctx.Done():
+			return nil
+		case <-ticker.C:
+			payload, err := json.Marshal(struct {
+				DeviceID string `json:"device_id"`
+				Time     string `json:"time"`
+			}{cfg.MQTT.DeviceID, time.Now().UTC().Format(time.RFC3339)})
+			if err != nil {
+				return err
+			}
+			if err := mqtt.Publish(ctx, manager, base+"/telemetry", payload); err != nil {
+				log.Printf("heartbeat: %v", err)
+			}
+		case message := <-inbox:
+			// Decode into a local command value only after rejecting retained messages.
+			var command struct {
+				ID      string `json:"id"`
+				Command string `json:"command"`
+			}
+			if message.Retain {
+				log.Print("ignoring retained command")
+				continue
+			}
+			if err := json.Unmarshal(message.Payload, &command); err != nil || command.ID == "" || command.Command != "ping" {
+				log.Print("ignoring malformed or unsupported command")
+				continue
+			}
+			// Echo the command ID so the backend can associate this pong with its ping.
+			response, err := json.Marshal(struct {
+				ID       string `json:"id"`
+				DeviceID string `json:"device_id"`
+				Status   string `json:"status"`
+			}{command.ID, cfg.MQTT.DeviceID, "pong"})
+			if err != nil {
+				return err
+			}
+			if err := mqtt.Publish(ctx, manager, base+"/responses", response); err != nil {
+				log.Printf("response: %v", err)
+			}
+		}
+	}
+}