snapshot of https://github.com/ThreeDotsLabs/watermill.git (master, 2026-09-15; blobs > 131072B omitted)

_examples/pubsubs/aws-sns/main.go

@@ -0,0 +1,133 @@
+// Sources for https://watermill.io/learn/getting-started/
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"net/url"
+	"time"
+
+	"github.com/aws/aws-sdk-go-v2/aws"
+	amazonsns "github.com/aws/aws-sdk-go-v2/service/sns"
+	amazonsqs "github.com/aws/aws-sdk-go-v2/service/sqs"
+	transport "github.com/aws/smithy-go/endpoints"
+	"github.com/samber/lo"
+
+	"github.com/ThreeDotsLabs/watermill"
+	"github.com/ThreeDotsLabs/watermill-aws/sns"
+	"github.com/ThreeDotsLabs/watermill-aws/sqs"
+	"github.com/ThreeDotsLabs/watermill/message"
+)
+
+func main() {
+	logger := watermill.NewStdLogger(false, false)
+
+	snsOpts := []func(*amazonsns.Options){
+		amazonsns.WithEndpointResolverV2(sns.OverrideEndpointResolver{
+			Endpoint: transport.Endpoint{
+				URI: *lo.Must(url.Parse("http://localstack:4566")),
+			},
+		}),
+	}
+
+	sqsOpts := []func(*amazonsqs.Options){
+		amazonsqs.WithEndpointResolverV2(sqs.OverrideEndpointResolver{
+			Endpoint: transport.Endpoint{
+				URI: *lo.Must(url.Parse("http://localstack:4566")),
+			},
+		}),
+	}
+
+	topicResolver, err := sns.NewGenerateArnTopicResolver("000000000000", "us-east-1")
+	if err != nil {
+		panic(err)
+	}
+
+	newSubscriber := func(name string) (message.Subscriber, error) {
+		subscriberConfig := sns.SubscriberConfig{
+			AWSConfig: aws.Config{
+				Credentials: aws.AnonymousCredentials{},
+			},
+			OptFns:        snsOpts,
+			TopicResolver: topicResolver,
+			GenerateSqsQueueName: func(ctx context.Context, snsTopic sns.TopicArn) (string, error) {
+				topic, err := sns.ExtractTopicNameFromTopicArn(snsTopic)
+				if err != nil {
+					return "", err
+				}
+
+				return fmt.Sprintf("%v-%v", topic, name), nil
+			},
+		}
+
+		sqsSubscriberConfig := sqs.SubscriberConfig{
+			AWSConfig: aws.Config{
+				Credentials: aws.AnonymousCredentials{},
+			},
+			OptFns: sqsOpts,
+		}
+
+		return sns.NewSubscriber(subscriberConfig, sqsSubscriberConfig, logger)
+	}
+
+	subA, err := newSubscriber("subA")
+	if err != nil {
+		panic(err)
+	}
+
+	subB, err := newSubscriber("subB")
+	if err != nil {
+		panic(err)
+	}
+
+	messagesA, err := subA.Subscribe(context.Background(), "example-topic")
+	if err != nil {
+		panic(err)
+	}
+
+	messagesB, err := subB.Subscribe(context.Background(), "example-topic")
+	if err != nil {
+		panic(err)
+	}
+
+	go process("A", messagesA)
+	go process("B", messagesB)
+
+	publisherConfig := sns.PublisherConfig{
+		AWSConfig: aws.Config{
+			Credentials: aws.AnonymousCredentials{},
+		},
+		OptFns:        snsOpts,
+		TopicResolver: topicResolver,
+	}
+
+	publisher, err := sns.NewPublisher(publisherConfig, logger)
+	if err != nil {
+		panic(err)
+	}
+
+	publishMessages(publisher)
+}
+
+func publishMessages(publisher message.Publisher) {
+	for {
+		msg := message.NewMessage(watermill.NewUUID(), []byte("Hello, world!"))
+
+		if err := publisher.Publish("example-topic", msg); err != nil {
+			panic(err)
+		}
+
+		time.Sleep(time.Second)
+	}
+}
+
+func process(prefix string, messages <-chan *message.Message) {
+	for msg := range messages {
+		log.Printf("%v received message: %s, payload: %s", prefix, msg.UUID, string(msg.Payload))
+
+		// we need to Acknowledge that we received and processed the message,
+		// otherwise, it will be resent over and over again.
+		msg.Ack()
+	}
+}