Decompress processor

[dlvenable]

Add a decompress processor:

processor:
  - decompress:
       keys: [my_gzip_key]
       type: gzip

Replace the value of the existing key with the decompressed value. Users likely don't want to save compressed values in OpenSearch.

See #3841 for more details.

[graytaylor0]

Should this processor also be responsible for decompressing from different encodings such as base64?

[dlvenable]

@graytaylor0 , Ultimately to get binary data into Data Prepper, the source is decoding something. And there is something similar going out of Data Prepper. With DynamoDB and OpenSearch, binary data comes in as a base64-encoded string. But, some sources may have a different approach.

I tend to think that our Event model should have an internal model to represent binary data. This model could even avoid encoding/decoding when it is unnecessary.

This may be a bigger change than we need right now. I'd say that the decompress processor can just assume a base64-encoded string since that is what we get from DynamoDB and OpenSearch.

[dlvenable]

@graytaylor0 , I put together an issue for handling binary data in a somewhat consistent way in Data Prepper: #4096