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

_examples/real-world-examples/sending-webhooks/router/main.go

@@ -0,0 +1,70 @@
+package main
+
+import (
+	"context"
+
+	"github.com/ThreeDotsLabs/watermill"
+	watermill_http "github.com/ThreeDotsLabs/watermill-http/pkg/http"
+	"github.com/ThreeDotsLabs/watermill-kafka/v3/pkg/kafka"
+	"github.com/ThreeDotsLabs/watermill/message"
+	"github.com/ThreeDotsLabs/watermill/message/router/plugin"
+)
+
+var (
+	logger = watermill.NewStdLogger(false, false)
+)
+
+// filterMessages passes the message along if its event type is one of acceptedTypes.
+func filterMessages(acceptedTypes ...string) message.HandlerFunc {
+	return func(msg *message.Message) ([]*message.Message, error) {
+		// the kafka producer sets this metadata so that we don't have to unmarshal the body
+		// just sort the messages based on event type metadata
+		msgEventType := msg.Metadata.Get("event_type")
+
+		for _, typ := range acceptedTypes {
+			if typ == msgEventType {
+				return message.Messages{msg}, nil
+			}
+		}
+
+		return nil, nil
+	}
+}
+
+func main() {
+	publisher, err := watermill_http.NewPublisher(watermill_http.PublisherConfig{
+		MarshalMessageFunc: watermill_http.DefaultMarshalMessageFunc,
+	}, logger)
+	if err != nil {
+		panic(err)
+	}
+
+	subscriber, err := kafka.NewSubscriber(
+		kafka.SubscriberConfig{
+			Brokers:     []string{"kafka:9092"},
+			Unmarshaler: kafka.DefaultMarshaler{},
+		},
+		logger,
+	)
+	if err != nil {
+		panic(err)
+	}
+
+	router, err := message.NewRouter(message.RouterConfig{}, logger)
+	if err != nil {
+		panic(err)
+	}
+
+	topic := "kafka_to_http_example"
+	url := "http://webhooks-server:8001/"
+
+	router.AddHandler("foo", topic, subscriber, url+"foo", publisher, filterMessages("Foo"))
+	router.AddHandler("foo_or_bar", topic, subscriber, url+"foo_or_bar", publisher, filterMessages("Foo", "Bar"))
+	router.AddHandler("all", topic, subscriber, url+"all", publisher, filterMessages("Foo", "Bar", "Baz"))
+	router.AddPlugin(plugin.SignalsHandler)
+
+	err = router.Run(context.Background())
+	if err != nil {
+		panic(err)
+	}
+}