Golang lambda function to send Streams data to Firehose

streams_to_firehose.go

package main

import (
	"github.com/apex/go-apex"
	"github.com/apex/go-apex/kinesis"
	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/firehose"
)

const (
	deliveryStreamName = "HarlowTest"
	maxBatchSize       = 400
)

func main() {
	kinesis.HandleFunc(func(event *kinesis.Event, ctx *apex.Context) error {
		svc := firehose.New(session.New())
		records := make([]*firehose.Record, 0, maxBatchSize)
		numRecords := len(event.Records)

		for i, r := range event.Records {
			records = append(
				records,
				&firehose.Record{Data: append(r.Kinesis.Data, '\n')},
			)

			if len(records) == maxBatchSize || i == (numRecords-1) {
				_, err := svc.PutRecordBatch(
					&firehose.PutRecordBatchInput{
						DeliveryStreamName: aws.String(deliveryStreamName),
						Records:            records,
					},
				)
				if err != nil {
					return err
				}
				records = records[:0]
			}
		}

		return nil
	})
}