71 lines
1.2 KiB
Go
71 lines
1.2 KiB
Go
|
package consumer
|
||
|
|
|
||
|
|
import (
|
||
|
|
"context"
|
||
|
|
"fmt"
|
||
|
|
"sync"
|
||
|
|
|
||
|
|
"github.com/segmentio/kafka-go"
|
||
|
|
)
|
||
|
|
|
||
|
|
type Consumer interface {
|
||
|
|
Start() error
|
||
|
|
Stop() error
|
||
|
|
}
|
||
|
|
|
||
|
|
func New() Consumer {
|
||
|
|
return &KafkaConsumer{}
|
||
|
|
}
|
||
|
|
|
||
|
|
type KafkaConsumer struct {
|
||
|
|
Consumer
|
||
|
|
|
||
|
|
reader *kafka.Reader
|
||
|
|
|
||
|
|
stopChan chan struct{}
|
||
|
|
stopWg sync.WaitGroup
|
||
|
|
}
|
||
|
|
|
||
|
|
func (kc *KafkaConsumer) Start() error {
|
||
|
|
if kc.stopChan != nil {
|
||
|
|
return fmt.Errorf("Consumer: already running. Stop it before starting it again")
|
||
|
|
}
|
||
|
|
kc.stopChan = make(chan struct{})
|
||
|
|
|
||
|
|
kc.reader = kafka.NewReader(kafka.ReaderConfig{
|
||
|
|
Brokers: []string{"192.168.1.50:9092"},
|
||
|
|
GroupID: "overflow-metric-group-id",
|
||
|
|
Topic: "overflow-metric-topic",
|
||
|
|
MinBytes: 10e3, // 10KB
|
||
|
|
MaxBytes: 10e6, // 10MB
|
||
|
|
})
|
||
|
|
|
||
|
|
if nil == kc.reader {
|
||
|
|
return fmt.Errorf("Consumer: cannot start kafka reader")
|
||
|
|
}
|
||
|
|
|
||
|
|
kc.stopWg.Add(1)
|
||
|
|
go handleRun(kc)
|
||
|
|
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
|
||
|
|
func (kc *KafkaConsumer) Stop() error {
|
||
|
|
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
|
||
|
|
func handleRun(kc *KafkaConsumer) {
|
||
|
|
defer func() {
|
||
|
|
kc.stopWg.Done()
|
||
|
|
}()
|
||
|
|
|
||
|
|
for {
|
||
|
|
m, err := kc.reader.ReadMessage(context.Background())
|
||
|
|
if err != nil {
|
||
|
|
break
|
||
|
|
}
|
||
|
|
fmt.Printf("message at topic/partition/offset %v/%v/%v: %s = %s\n", m.Topic, m.Partition, m.Offset, string(m.Key), string(m.Value))
|
||
|
|
}
|
||
|
|
}
|