[FEATURE] Send required REST APIs to OpenSearch #68
Description
Is your feature request related to a problem?
See step 3 described in #64
What solution would you like?
The initial connection from ExtensionsOrchestrator (in OpenSearch) to ExtensionsRunner (in each extension) is handled by this method:
https://github.com/opensearch-project/opensearch-sdk/blob/f9b3157af6b6b8cf05d4fb34ce6a8f529446a55f/src/main/java/org/opensearch/sdk/ExtensionsRunner.java#L100-L106
Another option is for ExtensionsOrchestrator to send a second request to the Extension after the initial acknowledgement, containing a different pluginRequest and then receive the list of APIs.
What alternatives have you considered?
Given the basic implementation at present, this seems like an unnecessary extra step, somewhat like pinging someone on chat and asking "Can I ask a question?" Rather than simply returning the extension name, this handler could return a more detailed response including the REST APIs that the Extension will require OpenSearch to handle.
However, having two handshakes provides a bit more flexibility in the future such as implementing #52 and sending the extensions.yaml information in the second interchange.
Do you have any additional context?
See also the DESIGN.md file (draft in #60)