Onboard Core and plugins for the Smoke test

[zelinh]

Since the smoke test framework (#5223) is already established, we aim to expand its capabilities by onboarding more OpenSearch API tests and selected plugin tests into the framework. This effort will enhance the testing coverage, ensuring greater reliability and functionality validation for OpenSearch and its plugins.

Objectives for the First Onboarding Phase:

OpenSearch Core API Tests:

Identify key OpenSearch APIs for inclusion in the smoke test framework.
Ensure comprehensive test coverage for critical functionalities.

Plugin Tests:

Select a few high-priority OpenSearch plugins to be onboarded during this phase.
Develop plugin-specific tests to validate their functionality when integrated with the OpenSearch core.

Collaboration with Plugin Owners:

We will work closely with plugin owners to encourage their participation in onboarding plugin tests into the smoke test framework. Providing detailed guidelines, documentation, and support will help them contribute effectively to the testing process.

Expected Outcome:

By onboarding core API tests and plugin tests, we aim to:

• Strengthen the robustness of OpenSearch releases.
• Provide a reliable, reusable testing framework for ongoing and future plugin validation.

[zelinh]

Tried to onboard k-NN into smoke test framework.
Able to test /_plugins/_knn/stats.

However, training model is a large task after ingesting the data, the cluster also stops every time we run /_plugins/_knn/models/_train. We would not include this as part of k-NN smoke tests.

[zelinh]

Working on index-management plugins and successfully onboarded few essential APIs to our smoke tests.