firehose event gets truncated/appended garbage characters about awsbeats

[mumoshu]

@di1214 Hi. I believe I spotted the source of issue.

This is data corruption. awsbeats is passing output from beat json encoder's output to the record sent to Firehose. This is wrong - beat's json encoder isn't designed to be used this way. It should copy the output before further usage.

So, instead of:

return &firehose.Record{Data: serializedEvent}, nil

We should write:

buf := make([]byte, len(serializedEvent))
copy(buf, serializedEvent)
serializedEvent = buf

return &firehose.Record{Data: serializedEvent}, nil

[di1214]

@mumoshu I have tested with your suggestion. It works now! thanks

[s12v]

@mumoshu, awesome catch