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123 lines
3.0 KiB
123 lines
3.0 KiB
package main
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import (
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"context"
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"fmt"
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"log"
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"os"
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"os/signal"
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"syscall"
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"time"
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"github.com/segmentio/kafka-go"
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)
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func main() {
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// Configuration
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brokerAddress := "localhost:9093" // Kafka gateway port (not SeaweedMQ broker port 17777)
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topicName := "_raw_messages" // Topic with "_" prefix - should skip schema validation
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groupID := "raw-message-consumer"
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fmt.Printf("Consuming messages from topic '%s' on broker '%s'\n", topicName, brokerAddress)
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// Create a new reader
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reader := kafka.NewReader(kafka.ReaderConfig{
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Brokers: []string{brokerAddress},
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Topic: topicName,
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GroupID: groupID,
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// Start reading from the beginning for testing
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StartOffset: kafka.FirstOffset,
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// Configure for quick consumption
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MinBytes: 1,
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MaxBytes: 10e6, // 10MB
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})
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defer reader.Close()
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// Set up signal handling for graceful shutdown
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ctx, cancel := context.WithCancel(context.Background())
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defer cancel()
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sigChan := make(chan os.Signal, 1)
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signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM)
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go func() {
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<-sigChan
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fmt.Println("\nReceived shutdown signal, stopping consumer...")
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cancel()
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}()
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fmt.Println("Starting to consume messages (Press Ctrl+C to stop)...")
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fmt.Println("=" + fmt.Sprintf("%60s", "="))
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messageCount := 0
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for {
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select {
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case <-ctx.Done():
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fmt.Printf("\nStopped consuming. Total messages processed: %d\n", messageCount)
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return
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default:
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// Set a timeout for reading messages
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msgCtx, msgCancel := context.WithTimeout(ctx, 5*time.Second)
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message, err := reader.ReadMessage(msgCtx)
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msgCancel()
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if err != nil {
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if err == context.DeadlineExceeded {
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fmt.Print(".")
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continue
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}
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log.Printf("Error reading message: %v", err)
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continue
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}
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messageCount++
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// Display message details
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fmt.Printf("\nMessage #%d:\n", messageCount)
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fmt.Printf(" Partition: %d, Offset: %d\n", message.Partition, message.Offset)
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fmt.Printf(" Key: %s\n", string(message.Key))
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fmt.Printf(" Value: %s\n", string(message.Value))
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fmt.Printf(" Timestamp: %s\n", message.Time.Format(time.RFC3339))
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// Display headers if present
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if len(message.Headers) > 0 {
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fmt.Printf(" Headers:\n")
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for _, header := range message.Headers {
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fmt.Printf(" %s: %s\n", header.Key, string(header.Value))
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}
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}
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// Try to detect content type
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contentType := detectContentType(message.Value)
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fmt.Printf(" Content Type: %s\n", contentType)
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fmt.Printf(" Raw Size: %d bytes\n", len(message.Value))
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fmt.Println(" " + fmt.Sprintf("%50s", "-"))
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}
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}
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}
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// detectContentType tries to determine the content type of the message
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func detectContentType(data []byte) string {
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if len(data) == 0 {
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return "empty"
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}
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// Check if it looks like JSON
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trimmed := string(data)
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if (trimmed[0] == '{' && trimmed[len(trimmed)-1] == '}') ||
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(trimmed[0] == '[' && trimmed[len(trimmed)-1] == ']') {
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return "JSON"
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}
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// Check if it's printable text
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for _, b := range data {
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if b < 32 && b != 9 && b != 10 && b != 13 { // Allow tab, LF, CR
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return "binary"
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}
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}
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return "text"
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}
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