What does this PR do?

Add CentML as a Remote Inference Provider in llama-stack.

This PR integrates CentML into llama-stack, enabling users to utilize CentML's models (meta-llama/Llama-3.3-70B-Instruct and meta-llama/Llama-3.1-405B-Instruct-FP8) for inference tasks like chat and text completions.

Right now only supported for conda deployments, simply build with llama stack build --template centml --image-type conda and run with llama stack run run.yaml --port <PORT> --env CENTML_API_KEY=<API_KEY>, then use llama-stack-client to perform any inference workload as needed.

Key Changes:

• Added CentML as a remote inference provider with model supports for meta-llama/Llama-3.3-70B-Instruct and meta-llama/Llama-3.1-405B-Instruct-FP8.

Addresses issue #809

Test Plan

The integration tests is only ran against the dev cluster becuase of model's availability. Plus the completion endpoints and lobprobs / tool-calling ability is not yet implemented on centml end, the tests are failing so currently there is no point to alter it. Please see the following manual testing on the integration tests for more details.

• Manual Testing:

  • Changed to development cluster for testing with llama_3b (production cluster only have 70b and 405b models).
  • right now only support for basic chat completion and models.
  • no support for tool-calling / completion / logprobs.

Passed test:

llama_stack/providers/tests/inference/test_text_inference.py::TestInference::test_model_list[llama_3b-centml] PASSED
llama_stack/providers/tests/inference/test_text_inference.py::TestInference::test_chat_completion_non_streaming[llama_3b-centml] PASSED
llama_stack/providers/tests/inference/test_text_inference.py::TestInference::test_chat_completion_streaming[llama_3b-centml] PASSED

Reproduction Instructions:

(P.S: the tests will only run on developement cluster because of model availability (which is this PR is not set to))

1. change URL to point to CentML development cluster
2. Run tests on dev cluster, result is the one above:

   pytest -s -v --providers inference=centml llama_stack/providers/tests/inference/test_text_inference.py  -m "llama_3b" --env CENTML_API_KEY=<API_KEY>

3. Perform inference:
   

Sources

• Related Issue: #809

Before submitting

• This PR fixes an issue (CentML inference provider support #809)
• Ran pre-commit to handle lint / formatting issues.
• Read the contributor guideline, Pull Request section.
• [] Updated relevant documentation.
• [] Wrote necessary unit or integration tests.