76 lines
1.7 KiB
Go
76 lines
1.7 KiB
Go
// Sources for https://watermill.io/learn/getting-started/
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package main
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import (
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"context"
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"log"
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"time"
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"github.com/IBM/sarama"
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"github.com/ThreeDotsLabs/watermill"
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"github.com/ThreeDotsLabs/watermill-kafka/v3/pkg/kafka"
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"github.com/ThreeDotsLabs/watermill/message"
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)
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func main() {
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saramaSubscriberConfig := kafka.DefaultSaramaSubscriberConfig()
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// equivalent of auto.offset.reset: earliest
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saramaSubscriberConfig.Consumer.Offsets.Initial = sarama.OffsetOldest
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subscriber, err := kafka.NewSubscriber(
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kafka.SubscriberConfig{
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Brokers: []string{"kafka:9092"},
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Unmarshaler: kafka.DefaultMarshaler{},
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OverwriteSaramaConfig: saramaSubscriberConfig,
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ConsumerGroup: "test_consumer_group",
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},
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watermill.NewStdLogger(false, false),
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)
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if err != nil {
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panic(err)
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}
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messages, err := subscriber.Subscribe(context.Background(), "example.topic")
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if err != nil {
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panic(err)
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}
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go process(messages)
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publisher, err := kafka.NewPublisher(
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kafka.PublisherConfig{
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Brokers: []string{"kafka:9092"},
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Marshaler: kafka.DefaultMarshaler{},
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},
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watermill.NewStdLogger(false, false),
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)
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if err != nil {
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panic(err)
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}
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publishMessages(publisher)
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}
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func publishMessages(publisher message.Publisher) {
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for {
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msg := message.NewMessage(watermill.NewUUID(), []byte("Hello, world!"))
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if err := publisher.Publish("example.topic", msg); err != nil {
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panic(err)
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}
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time.Sleep(time.Second)
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}
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}
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func process(messages <-chan *message.Message) {
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for msg := range messages {
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log.Printf("received message: %s, payload: %s", msg.UUID, string(msg.Payload))
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// we need to Acknowledge that we received and processed the message,
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// otherwise, it will be resent over and over again.
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msg.Ack()
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}
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}
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