Send data in cloudevents format to Kafka topic - go

Question

Right now I have this code and it works fine. (It sends some json format data to Kafka topic)
j, err := json.Marshal(data)
if err != nil {
log.Fatal(err)
}
msg := &sarama.ProducerMessage{
Topic: tName,
Value: sarama.StringEncoder(j),
}
_, _, err = producer.SendMessage(msg)
but somebody wishes ho have this data in cloudevents format. -> https://github.com/cloudevents/sdk-go
so what should I do because this Event structure can not be directly casted to string.
type Event struct {
Context EventContext
DataEncoded []byte
// DataBase64 indicates if the event, when serialized, represents
// the data field using the base64 encoding.
// In v0.3, this field is superseded by DataContentEncoding
DataBase64 bool
FieldErrors map[string]error
}
so this code won't even compile.
j, err := json.Marshal(data)
if err != nil {
log.Fatal(err)
}
//...
event := cloudevents.NewEvent()
event.SetSource("example/uri")
event.SetType("example.type")
event.SetData(cloudevents.ApplicationJSON, j)
producerMsg := &sarama.ProducerMessage{
Topic: s.outputTopic,
Value: sarama.StringEncoder(event),
}
_, _, err = s.producer.SendMessage(producerMsg)
What should I do to send this Event to Kafka? Try to cast event.DataEncoded to string or something like that?
btw.
Programming language is golang.

Answer 1

Did you see the section of the docs that serialized the event?
https://github.com/cloudevents/sdk-go#serializedeserialize-a-cloudevent
event := cloudevents.NewEvent()
event.SetSource("example/uri")
event.SetType("example.type")
// data here is a map[string] interface{}, or some other Struct type representing the "example.type" schema type above
event.SetData(cloudevents.ApplicationJSON, data)
bytes, err := json.Marshal(event)
if err != nil {
log.Fatal(err)
}
producerMsg := &sarama.ProducerMessage{
Topic: s.outputTopic,
Value: bytes, // you've already encoded the event
}
Otherwise, be sure to look at the sample code provided that uses the CloudEvent client https://github.com/cloudevents/sdk-go/blob/main/samples/kafka/sender/main.go
sender, err := kafka_sarama.NewSender([]string{"127.0.0.1:9092"}, saramaConfig, "test-topic")
if err != nil {
log.Fatalf("failed to create protocol: %s", err.Error())
}
defer sender.Close(context.Background())
c, err := cloudevents.NewClient(sender, cloudevents.WithTimeNow(), cloudevents.WithUUIDs())
if err != nil {
log.Fatalf("failed to create client, %v", err)
}
event := cloudevents.NewEvent()
event.Set...
c.Send(..., event)
...