# README

Apache Pulsar Go Client Library

A Go client library for the Apache Pulsar project.

Goal

This projects is developing a pure-Go client library for Pulsar that does not depend on the C++ Pulsar library.

Once feature parity and stability are reached, this will supersede the current CGo based library.

Requirements

Go 1.15+

Status

Check the Projects page at https://github.com/apache/pulsar-client-go/projects for tracking the status and the progress.

Usage

Import the client library:

import "github.com/apache/pulsar-client-go/pulsar"

Create a Producer:

client, err := pulsar.NewClient(pulsar.ClientOptions{
    URL: "pulsar://localhost:6650",
})

defer client.Close()

producer, err := client.CreateProducer(pulsar.ProducerOptions{
	Topic: "my-topic",
})

_, err = producer.Send(context.Background(), &pulsar.ProducerMessage{
	Payload: []byte("hello"),
})

defer producer.Close()

if err != nil {
    fmt.Println("Failed to publish message", err)
} else {
    fmt.Println("Published message")
}

Create a Consumer:

client, err := pulsar.NewClient(pulsar.ClientOptions{
    URL: "pulsar://localhost:6650",
})

defer client.Close()

consumer, err := client.Subscribe(pulsar.ConsumerOptions{
        Topic:            "my-topic",
        SubscriptionName: "my-sub",
        Type:             pulsar.Shared,
    })

defer consumer.Close()

msg, err := consumer.Receive(context.Background())
    if err != nil {
        log.Fatal(err)
    }

fmt.Printf("Received message msgId: %#v -- content: '%s'\n",
            msg.ID(), string(msg.Payload()))

Create a Reader:

client, err := pulsar.NewClient(pulsar.ClientOptions{URL: "pulsar://localhost:6650"})
if err != nil {
	log.Fatal(err)
}

defer client.Close()

reader, err := client.CreateReader(pulsar.ReaderOptions{
	Topic:          "topic-1",
	StartMessageID: pulsar.EarliestMessageID(),
})
if err != nil {
	log.Fatal(err)
}
defer reader.Close()

for reader.HasNext() {
	msg, err := reader.Next(context.Background())
	if err != nil {
		log.Fatal(err)
	}

	fmt.Printf("Received message msgId: %#v -- content: '%s'\n",
		msg.ID(), string(msg.Payload()))
}