Fixes to the Nebula LLM Integration (#8918)

This addresses some issues with introducing the Nebula LLM to LangChain
in this PR:
https://github.com/langchain-ai/langchain/pull/8876

This fixes the following:
- Removes `SYMBLAI` from variable names
- Fixes bug with `Bearer` for the API KEY


Thanks again in advance for your help!
cc: @hwchase17, @baskaryan

---------

Co-authored-by: dvonthenen <david.vonthenen@gmail.com>

docs/extras/integrations/llms/symblai_nebula.ipynb

@@ -34,9 +34,9 @@
    "source": [
     "import os\n",
     "\n",
-    "os.environ[\"SYMBLAI_NEBULA_SERVICE_URL\"] = SYMBLAI_NEBULA_SERVICE_URL\n",
+    "os.environ[\"NEBULA_SERVICE_URL\"] = NEBULA_SERVICE_URL\n",
-    "os.environ[\"SYMBLAI_NEBULA_SERVICE_PATH\"] = SYMBLAI_NEBULA_SERVICE_PATH\n",
+    "os.environ[\"NEBULA_SERVICE_PATH\"] = NEBULA_SERVICE_PATH\n",
-    "os.environ[\"SYMBLAI_NEBULA_SERVICE_TOKEN\"] = SYMBLAI_NEBULA_SERVICE_TOKEN"
+    "os.environ[\"NEBULA_SERVICE_API_KEY\"] = NEBULA_SERVICE_API_KEY"
    ]
   },
   {

libs/langchain/langchain/llms/symblai_nebula.py

@@ -9,8 +9,8 @@ from langchain.llms.base import LLM
 from langchain.llms.utils import enforce_stop_tokens
 from langchain.utils import get_from_dict_or_env
 
-DEFAULT_SYMBLAI_NEBULA_SERVICE_URL = "https://api-nebula.symbl.ai"
+DEFAULT_NEBULA_SERVICE_URL = "https://api-nebula.symbl.ai"
-DEFAULT_SYMBLAI_NEBULA_SERVICE_PATH = "/v1/model/generate"
+DEFAULT_NEBULA_SERVICE_PATH = "/v1/model/generate"
 
 logger = logging.getLogger(__name__)
 
@@ -18,8 +18,8 @@ logger = logging.getLogger(__name__)
 class Nebula(LLM):
     """Nebula Service models.
 
-    To use, you should have the environment variable ``SYMBLAI_NEBULA_SERVICE_URL``,
+    To use, you should have the environment variable ``NEBULA_SERVICE_URL``,
-    ``SYMBLAI_NEBULA_SERVICE_PATH`` and ``SYMBLAI_NEBULA_SERVICE_TOKEN`` set with your Nebula
+    ``NEBULA_SERVICE_PATH`` and ``NEBULA_SERVICE_API_KEY`` set with your Nebula
     Service, or pass it as a named parameter to the constructor.
 
     Example:
@@ -30,21 +30,8 @@ class Nebula(LLM):
             nebula = Nebula(
                 nebula_service_url="SERVICE_URL",
                 nebula_service_path="SERVICE_ROUTE",
-                nebula_service_token="SERVICE_TOKEN",
+                nebula_api_key="SERVICE_TOKEN",
             )
-
-            # Use Ray for distributed processing
-            import ray
-
-            prompt_list=[]
-
-            @ray.remote
-            def send_query(llm, prompt):
-                resp = llm(prompt)
-                return resp
-
-            futures = [send_query.remote(nebula, prompt) for prompt in prompt_list]
-            results = ray.get(futures)
     """  # noqa: E501
 
     """Key/value arguments to pass to the model. Reserved for future use"""
@@ -53,7 +40,7 @@ class Nebula(LLM):
     """Optional"""
     nebula_service_url: Optional[str] = None
     nebula_service_path: Optional[str] = None
-    nebula_service_token: Optional[str] = None
+    nebula_api_key: Optional[str] = None
     conversation: str = ""
     return_scores: Optional[str] = "false"
     max_new_tokens: Optional[int] = 2048
@@ -69,20 +56,21 @@ class Nebula(LLM):
     def validate_environment(cls, values: Dict) -> Dict:
         """Validate that api key and python package exists in environment."""
         nebula_service_url = get_from_dict_or_env(
-            values, "nebula_service_url", "SYMBLAI_NEBULA_SERVICE_URL"
+            values,
+            "nebula_service_url",
+            "NEBULA_SERVICE_URL",
+            DEFAULT_NEBULA_SERVICE_URL,
         )
         nebula_service_path = get_from_dict_or_env(
-            values, "nebula_service_path", "SYMBLAI_NEBULA_SERVICE_PATH"
+            values,
+            "nebula_service_path",
+            "NEBULA_SERVICE_PATH",
+            DEFAULT_NEBULA_SERVICE_PATH,
         )
-        nebula_service_token = get_from_dict_or_env(
+        nebula_api_key = get_from_dict_or_env(
-            values, "nebula_service_token", "SYMBLAI_NEBULA_SERVICE_TOKEN"
+            values, "nebula_api_key", "NEBULA_SERVICE_API_KEY", ""
         )
 
-        if len(nebula_service_url) == 0:
-            nebula_service_url = DEFAULT_SYMBLAI_NEBULA_SERVICE_URL
-        if len(nebula_service_path) == 0:
-            nebula_service_path = DEFAULT_SYMBLAI_NEBULA_SERVICE_PATH
-
         if nebula_service_url.endswith("/"):
             nebula_service_url = nebula_service_url[:-1]
         if not nebula_service_path.startswith("/"):
@@ -94,7 +82,7 @@ class Nebula(LLM):
             nebula_service_endpoint = f"{nebula_service_url}{nebula_service_path}"
             headers = {
                 "Content-Type": "application/json",
-                "ApiKey": f"Bearer {nebula_service_token}",
+                "ApiKey": "{nebula_api_key}",
                 }
             requests.get(nebula_service_endpoint, headers=headers)
         except requests.exceptions.RequestException as e:
@@ -103,7 +91,7 @@ class Nebula(LLM):
 
         values["nebula_service_url"] = nebula_service_url
         values["nebula_service_path"] = nebula_service_path
-        values["nebula_service_token"] = nebula_service_token
+        values["nebula_api_key"] = nebula_api_key
 
         return values
 
@@ -147,7 +135,7 @@ class Nebula(LLM):
 
         headers = {
             "Content-Type": "application/json",
-            "ApiKey": f"Bearer {self.nebula_service_token}",
+            "ApiKey": f"{self.nebula_api_key}",
         }
 
         body = {