Bug: #898

Describe the bug
When using output.elasticsearch with batch_op_type: create (required for Elasticsearch/OpenSearch data streams), file.d reports errors even though documents are successfully created.
Error message:

unknown elasticsearch response, 'index' field in the response is empty

This happens because bulk responses contain "create": {...} instead of "index": {...}, which the plugin does not currently parse.

To Reproduce
Steps to reproduce the behavior:

Configure output.elasticsearch with batch_op_type: create.

Send logs to an Elasticsearch/OpenSearch data stream (index name starts with .ds-).

Observe file.d logs:

unknown elasticsearch response, 'index' field in the response is empty
some events from batch aren't written

Expected behavior
file.d should correctly parse bulk responses containing "create": {...} when batch_op_type: create is used, and treat them as successful writes.

Additional context

Version: file.d [v0.61.0]

Platform: Kubernetes

Elasticsearch/OpenSearch: OpenSearch [2.18]

Example response from server:

{"create":{
"_index":".ds-file-d-dev-cluster-apps-order-service-000069",
"_id":"ymfJcJkBL5nPyj0lnB8M",
"_version":1,
"result":"created",
"_shards":{"total":2,"successful":2,"failed":0},
"_seq_no":2826141,
"_primary_term":1,
"status":201
}}
Just to clarify: it’s not only about suppressing error logs.
Right now some events are actually marked as failed, so logs from search-gateway (and potentially other services) do not appear in OpenSearch when writing into data streams.

We need proper support for bulk responses with "create": {...} in output.elasticsearch (when batch_op_type: create is used).
Suppressing the error is not enough — the plugin should treat these responses as successful so that all events are indexed.