add varaible service base

src/backend/base/langflow/services/settings/base.py

@@ -73,6 +73,10 @@ class Settings(BaseSettings):
     max_overflow: int = 20
     """The number of connections to allow that can be opened beyond the pool size. If not provided, the default is 10."""
     cache_type: str = "async"
+
+    """The store can be 'db' or 'kubernetes'."""
+    variable_store: str = "db"
+
     remove_api_keys: bool = False
     components_path: List[str] = []
     langchain_cache: str = "InMemoryCache"

src/backend/base/langflow/services/variable/base.py

@@ -0,0 +1,109 @@
+import abc
+from typing import Optional, Union
+from uuid import UUID
+
+from fastapi import Depends
+from sqlmodel import Session
+
+from langflow.services.base import Service
+from langflow.services.database.models.variable.model import Variable
+from langflow.services.deps import get_session
+
+class VariableService(Service):
+    """
+    Abstract base class for a variable service.
+    """
+    name = "variable_service"
+
+    @abc.abstractmethod
+    def initialize_user_variables(self, user_id: Union[UUID, str], session: Session) -> None:
+        """
+        Initialize user variables.
+
+        Args:
+            user_id: The user ID.
+            session: The database session.
+        """
+
+    @abc.abstractmethod
+    def get_variable(self, user_id: Union[UUID, str], name: str, field: str, session: Session) -> str:
+        """
+        Get a variable value.
+
+        Args:
+            user_id: The user ID.
+            name: The name of the variable.
+            field: The field of the variable.
+            session: The database session.
+
+        Returns:
+            The value of the variable.
+        """
+    
+    @abc.abstractmethod
+    def list_variables(self, user_id: Union[UUID, str], session: Session) -> list[Optional[str]]:
+        """
+        List all variables.
+
+        Args:
+            user_id: The user ID.
+            session: The database session.
+
+        Returns:
+            A list of variable names.
+        """
+    
+    @abc.abstractmethod
+    def update_variable(self, user_id: Union[UUID, str], name: str, value: str, session: Session) -> Variable:
+        """
+        Update a variable.
+
+        Args:
+            user_id: The user ID.
+            name: The name of the variable.
+            value: The value of the variable.
+            session: The database session.
+
+        Returns:
+            The updated variable.
+        """ 
+
+    @abc.abstractmethod
+    def delete_variable(self, user_id: Union[UUID, str], name: str, session: Session) -> Variable:
+        """
+        Delete a variable.
+
+        Args:
+            user_id: The user ID.
+            name: The name of the variable.
+            session: The database session.
+
+        Returns:
+            The deleted variable.
+        """ 
+    
+    @abc.abstractmethod
+    def create_variable(
+        self,
+        user_id: Union[UUID, str],
+        name: str,
+        value: str,
+        default_fields: list[str] = [],
+        _type: str = "Generic",
+        session: Session = Depends(get_session),
+    ) -> Variable:
+        """
+        Create a variable.
+
+        Args:
+            user_id: The user ID.
+            name: The name of the variable.
+            value: The value of the variable.
+            default_fields: The default fields of the variable.
+            _type: The type of the variable.
+            session: The database session.
+
+        Returns:
+            The created variable.
+        """
+

src/backend/base/langflow/services/variable/factory.py

@@ -1,7 +1,7 @@
 from typing import TYPE_CHECKING
 
 from langflow.services.factory import ServiceFactory
-from langflow.services.variable.service import VariableService
+from langflow.services.variable.service import DatabaseVariableService, KubernetesSecretService
 
 if TYPE_CHECKING:
     from langflow.services.settings.service import SettingsService
@@ -12,4 +12,10 @@ class VariableServiceFactory(ServiceFactory):
         super().__init__(VariableService)
 
     def create(self, settings_service: "SettingsService"):
-        return VariableService(settings_service)
+        # here you would have logic to create and configure a VariableService
+        # based on the settings_service
+
+        if settings_service.settings.variable_store == "kubernetes":
+            return KubernetesSecretService(settings_service)
+        else:
+            return DatabaseVariableService(settings_service)

src/backend/base/langflow/services/variable/service.py

@@ -8,6 +8,7 @@ from sqlmodel import Session, select
 
 from langflow.services.auth import utils as auth_utils
 from langflow.services.base import Service
+from langflow.services.variable.base import VariableService
 from langflow.services.database.models.variable.model import Variable, VariableCreate
 from langflow.services.deps import get_session
 
@@ -15,8 +16,7 @@ if TYPE_CHECKING:
     from langflow.services.settings.service import SettingsService
 
 
-class VariableService(Service):
-    name = "variable_service"
+class DatabaseVariableService(VariableService, Service):
 
     def __init__(self, settings_service: "SettingsService"):
         self.settings_service = settings_service
@@ -127,3 +127,53 @@ class VariableService(Service):
         session.commit()
         session.refresh(variable)
         return variable
+
+
+
+class KubernetesSecretService(VariableService, Service):
+
+    def __init__(self, settings_service: "SettingsService"):
+        self.settings_service = settings_service
+
+    def initialize_user_variables(self, user_id: Union[UUID, str], session: Session = Depends(get_session)):
+        return
+
+    def get_variable(
+        self,
+        user_id: Union[UUID, str],
+        name: str,
+        field: str,
+        session: Session = Depends(get_session),
+    ) -> str:
+        return ""
+
+    def list_variables(self, user_id: Union[UUID, str], session: Session = Depends(get_session)) -> list[Optional[str]]:
+        return []
+    
+    def update_variable(
+        self,
+        user_id: Union[UUID, str],
+        name: str,
+        value: str,
+        session: Session = Depends(get_session),
+    ):
+        return
+    
+    def delete_variable(    
+        self,
+        user_id: Union[UUID, str],
+        name: str,
+        session: Session = Depends(get_session),
+    ):
+        return
+    
+    def create_variable(
+        self,
+        user_id: Union[UUID, str],
+        name: str,
+        value: str,
+        default_fields: list[str] = [],
+        _type: str = "Generic",
+        session: Session = Depends(get_session),
+    ):
+        return