ElasticsearchDelivery failed to parse

Question

I am using a lambda function to send data to kinesis-firehose then to elasticsearch. In my ElasticsearchDelivery log I am getting the following error:

{"type":"mapper_parsing_exception","reason":"failed to parse","caused_by":{"type":"not_x_content_exception","reason":"Compressor detection can only be called on some xcontent bytes or compressed xcontent bytes"}}

I am struggling to find solutions for this one online. I suspect there is something wrong with how I am returning the data in my lambda function but not sure how to fix it.

This is my lambda function:

exports.handler = async (event) => {
        var output = [];
        var records = event.records;
        records.map(function (record) {
            output.push({
                'recordId': record['recordId'],
                'result': 'Ok',
                'data':new Buffer(record.data).toString('base64') 
            })
        });

        console.log("OUTPUT!!!!:", output)
        return {'records': output};
    };

Answer 1

I had to change the data to:

'data': record.data.toString('base64')