feat: add bedrock runtime agent for knowledge base

[yuye-aws]

Description

Enable users to register bedrock runtime agent for calling bedrock knowledge base.

Issues Resolved

POST /_plugins/_ml/connectors/_create
{
  "name": "Amazon Bedrock Connector: knowledge",
  "description": "The connector to the Bedrock knowledge base",
  "version": 1,
  "protocol": "aws_sigv4",
  "parameters": {
    "region": "...",
    "service_name": "bedrock"
  },
  "credential": {
    "access_key": "...",
    "secret_key": "..."
  },
  "actions": [
    {
      "action_type": "predict",
      "method": "POST",
      "url": "...",
      "headers": {
        "content-type": "application/json",
        "x-amz-content-sha256": "required"
      },
      "request_body": "{\"retrievalQuery\": {\"text\": \"${parameters.text}\"}}"
    }
  ]
}

POST /_plugins/_ml/models/_register?deploy=true
{
  "name": "bedrock: knowledge base",
  "function_name": "remote",
  "description": "Test connector for bedrock knowledge base",
  "connector_id": <connector_id>
}

POST /_plugins/_ml/models/<model_id>/_predict/
{
  "parameters": {
    "text": "aws 2021"
  }
}

Check List

• New functionality includes testing.
  • All tests pass
• New functionality has been documented.
  • New functionality has javadoc added
• Commits are signed per the DCO using --signoff

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[Hailong-am]

should we combine these two bedrock endpoint into one?

[yuye-aws]

Do you mean regex like the following?
^https://(?:bedrock-runtime|bedrock-agent-runtime)\\..*[a-z0-9-]\\.amazonaws\\.com/.*$

But I think the current code is more readable, so I prefer remain unchanged.

[Hailong-am]

I mean bedrock.* to include all bedrock related, so we don't need to add more if there has another bedrock-xyz. I think it's ok to keep as two for now and merge into one if we have more bedrock endpoints comes after.