feat: Part 2 - Add custom LLM inference class

ragengine/config.py

@@ -0,0 +1,20 @@
+# config.py
+
+# Variables are set via environment variables from the RAGEngine CR
+# and exposed to the pod. For example, InferenceURL is specified in the CR and 
+# passed to the pod via env variables.
+
+import os
+
+EMBEDDING_TYPE = os.getenv("EMBEDDING_TYPE", "local")
+EMBEDDING_URL = os.getenv("EMBEDDING_URL")
+
+INFERENCE_URL = os.getenv("INFERENCE_URL", "http://localhost:5000/chat")
+INFERENCE_ACCESS_SECRET = os.getenv("AccessSecret", "default-inference-secret")
+# RESPONSE_FIELD = os.getenv("RESPONSE_FIELD", "result")
+
+MODEL_ID = os.getenv("MODEL_ID", "BAAI/bge-small-en-v1.5")
+VECTOR_DB_TYPE = os.getenv("VECTOR_DB_TYPE", "faiss")
+INDEX_SERVICE_NAME = os.getenv("INDEX_SERVICE_NAME", "default-index-service")
+ACCESS_SECRET = os.getenv("ACCESS_SECRET", "default-access-secret")
+PERSIST_DIR = "storage"

ragengine/inference/inference.py

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+from typing import Any
+from llama_index.core.llms import CustomLLM, CompletionResponse, LLMMetadata, CompletionResponseGen
+from llama_index.llms.openai import OpenAI
+from llama_index.core.llms.callbacks import llm_completion_callback
+import requests
+from config import INFERENCE_URL, INFERENCE_ACCESS_SECRET #, RESPONSE_FIELD
+
+class Inference(CustomLLM):
+    params: dict = {}
+
+    def set_params(self, params: dict) -> None:
+        self.params = params
+
+    def get_param(self, key, default=None):
+        return self.params.get(key, default)
+
+    @llm_completion_callback()
+    def stream_complete(self, prompt: str, **kwargs: Any) -> CompletionResponseGen:
+        pass
+
+    @llm_completion_callback()
+    def complete(self, prompt: str, **kwargs) -> CompletionResponse:
+        try:
+            if "openai" in INFERENCE_URL:
+                return self._openai_complete(prompt, **kwargs, **self.params)
+            else:
+                return self._custom_api_complete(prompt, **kwargs, **self.params)
+        finally:
+            # Clear params after the completion is done
+            self.params = {}
+
+    def _openai_complete(self, prompt: str, **kwargs: Any) -> CompletionResponse:
+        llm = OpenAI(
+            api_key=INFERENCE_ACCESS_SECRET,
+            **kwargs  # Pass all kwargs directly; kwargs may include model, temperature, max_tokens, etc.
+        )
+        return llm.complete(prompt)
+
+    def _custom_api_complete(self, prompt: str, **kwargs: Any) -> CompletionResponse:
+        headers = {"Authorization": f"Bearer {INFERENCE_ACCESS_SECRET}"}
+        data = {"prompt": prompt, **kwargs}
+
+        response = requests.post(INFERENCE_URL, json=data, headers=headers)
+        response_data = response.json()
+
+        # Dynamically extract the field from the response based on the specified response_field
+        # completion_text = response_data.get(RESPONSE_FIELD, "No response field found") # not necessary for now
+        return CompletionResponse(text=str(response_data))
+
+    @property
+    def metadata(self) -> LLMMetadata:
+        """Get LLM metadata."""
+        return LLMMetadata()