Danube-go client

The Go Client library for interacting with Danube Pub/Sub messaging platform.

Danube is an open-source distributed Pub/Sub messaging platform written in Rust. Consult the documentation for supported concepts and the platform architecture.

Example usage

Check out the example files.

Start the Danube server

Use the instructions from the documentation to run the Danube broker/cluster.

Create Producer

client := danube.NewClient().ServiceURL("127.0.0.1:6650").Build()

ctx := context.Background()
topic := "/default/test_topic"
producerName := "test_producer"

producer, err := client.NewProducer(ctx).
    WithName(producerName).
    WithTopic(topic).
    Build()
if err != nil {
    log.Fatalf("unable to initialize the producer: %v", err)
}

if err := producer.Create(ctx); err != nil {
    log.Fatalf("Failed to create producer: %v", err)
}
log.Printf("The Producer %s was created", producerName)

payload := fmt.Sprintln("Hello Danube")

// Convert string to bytes
bytes_payload := []byte(payload)

// You can send the payload along with the user defined attributes, in this case is nil
messageID, err := producer.Send(ctx, bytes_payload, nil)
if err != nil {
    log.Fatalf("Failed to send message: %v", err)
}
log.Printf("The Message with id %v was sent", messageID)

Create Consumer

client := danube.NewClient().ServiceURL("127.0.0.1:6650").Build()

ctx := context.Background()
topic := "/default/test_topic"
consumerName := "test_consumer"
subscriptionName := "test_subscription"
subType := danube.Exclusive

consumer, err := client.NewConsumer(ctx).
    WithConsumerName(consumerName).
    WithTopic(topic).
    WithSubscription(subscriptionName).
    WithSubscriptionType(subType).
    Build()
if err != nil {
    log.Fatalf("Failed to initialize the consumer: %v", err)
}

// Request to subscribe to the topic and create the resources on the Danube Broker
if err := consumer.Subscribe(ctx); err != nil {
    log.Fatalf("Failed to subscribe: %v", err)
}
log.Printf("The Consumer %s was created", consumerName)

// Request to receive messages
stream, err := consumer.Receive(ctx)
if err != nil {
    log.Fatalf("Failed to receive messages: %v", err)
}

// consume the messages from the go channel
for msg := range stream {
    fmt.Printf("Received message: %+v\n", string(msg.GetPayload()))

}

Contribution

I'm working on improving and adding new features. Please feel free to contribute or report any issues you encounter.

Use latest DanubeApi.proto file

Make sure the proto/DanubeApi.proto is the latest from Danube project.

If not replace the file and add at the top of the file

option go_package = "github.com/danrusei/danube-go/proto";

right after the package danube;

In order to generate the Go grpc code you need the following packages installed:

go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@latest

And generate the Go code from the proto file:

protoc --proto_path=./proto --go_out=./proto --go-grpc_out=./proto --go_opt=paths=source_relative      --go-grpc_opt=paths=source_relative proto/DanubeApi.proto