[DOC] Add documentation page for opensearch_api source in Data Prepper

[divakarsingh]

What do you want to do?

• Request a change to existing documentation
• Add new documentation
• Report a technical problem with the documentation
• Other

Tell us about your request.

The opensearch_api source plugin for Data Prepper has no documentation page on the docs portal. The URL https://docs.opensearch.org/latest/data-prepper/pipelines/configuration/sources/opensearch-api-source/ returns 404.

Every other Data Prepper source plugin (http_source, otel_trace_source, kafka, etc.) has a corresponding page on the docs website.

Additionally, the existing plugin README (https://github.com/opensearch-project/data-prepper/blob/main/data-prepper-plugins/opensearch-api-source/README.md) is missing several important details:

• Supported bulk actions (index, create, update, delete) and which require a document body
• Event metadata attributes set per action (opensearch_action, opensearch_index, opensearch_id, opensearch_routing, opensearch_pipeline)
• Response body format ({took, errors, items[]}) — clients depend on this for error handling
• Integration examples showing usage with Flink OpenSearch Connector, opensearch-py, and Logstash

A new page needs to be created at opensearch-project/documentation-website/_data-prepper/pipelines/configuration/sources/opensearch-api-source.md covering:

• Overview and use cases (accepting OpenSearch Bulk API traffic from standard clients like Flink, Logstash, opensearch-py)
• Configuration parameters (port, path, authentication, SSL, compression)
• Supported bulk actions (index, create, update, delete)
• Response format ({took, errors, items[]})
• Event metadata attributes (opensearch_action, opensearch_index, opensearch_id, opensearch_routing, opensearch_pipeline)
• Metrics reference
• Example pipeline configurations

Version: 2.15+

What other resources are available?

• Plugin source: https://github.com/opensearch-project/data-prepper/tree/main/data-prepper-plugins/opensearch-api-source
• Existing README: https://github.com/opensearch-project/data-prepper/blob/main/data-prepper-plugins/opensearch-api-source/README.md

[kolchfa-aws]

Thanks, @divakarsingh! Would you be willing to put up a PR for this?

[divakarsingh]

sure @kolchfa-aws , just done.