Community: Add mistral oss model support to azureml endpoints, plus configurable timeout (#19123)

- **Description:** There was no formatter for mistral models for Azure
ML endpoints. Adding that, plus a configurable timeout (it was hard
coded before)
- **Dependencies:** none
- **Twitter handle:** @tjaffri @docugami

libs/community/langchain_community/chat_models/azureml_endpoint.py

@@ -143,6 +143,44 @@ class LlamaChatContentFormatter(ContentFormatterBase):
         raise ValueError(f"`api_type` {api_type} is not supported by this formatter")
 
 
+class MistralChatContentFormatter(LlamaChatContentFormatter):
+    """Content formatter for `Mistral`."""
+
+    def format_messages_request_payload(
+        self,
+        messages: List[BaseMessage],
+        model_kwargs: Dict,
+        api_type: AzureMLEndpointApiType,
+    ) -> bytes:
+        """Formats the request according to the chosen api"""
+        chat_messages = [self._convert_message_to_dict(message) for message in messages]
+
+        if chat_messages and chat_messages[0]["role"] == "system":
+            # Mistral OSS models do not explicitly support system prompts, so we have to
+            # stash in the first user prompt
+            chat_messages[1]["content"] = (
+                chat_messages[0]["content"] + "\n\n" + chat_messages[1]["content"]
+            )
+            del chat_messages[0]
+
+        if api_type == AzureMLEndpointApiType.realtime:
+            request_payload = json.dumps(
+                {
+                    "input_data": {
+                        "input_string": chat_messages,
+                        "parameters": model_kwargs,
+                    }
+                }
+            )
+        elif api_type == AzureMLEndpointApiType.serverless:
+            request_payload = json.dumps({"messages": chat_messages, **model_kwargs})
+        else:
+            raise ValueError(
+                f"`api_type` {api_type} is not supported by this formatter"
+            )
+        return str.encode(request_payload)
+
+
 class AzureMLChatOnlineEndpoint(BaseChatModel, AzureMLBaseEndpoint):
     """Azure ML Online Endpoint chat models.