CASMCMS-9225: Create ApiClients class and provide it to BOS operators…

… inside a context manager

src/bos/operators/base.py

@@ -27,6 +27,7 @@
 """
 
 from abc import ABC, abstractmethod
+from contextlib import ExitStack
 import itertools
 import logging
 import threading
@@ -55,6 +56,41 @@ class MissingSessionData(BaseOperatorException):
     desired state.
     """
 
+class ApiClients:
+    """
+    Context manager to provide API clients to BOS operators.
+    Essentially, it uses an ExitStack context manager to manage the API clients.
+    """
+
+    def __init__(self):
+        #self.bos = BOSClient()
+        #self.bss = BSSClient()
+        #self.cfs = CFSClient()
+        #self.hsm = HSMClient()
+        #self.ims = IMSClient()
+        #self.pcs = PCSClient()
+        self._stack = ExitStack()
+
+    def __enter__(self):
+        """
+        Enter context for all API clients
+        """
+        #self._stack.enter_context(self.bos)
+        #self._stack.enter_context(self.bss)
+        #self._stack.enter_context(self.cfs)
+        #self._stack.enter_context(self.hsm)
+        #self._stack.enter_context(self.ims)
+        #self._stack.enter_context(self.pcs)
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        """
+        Exit context on the exit stack, which will take care of exiting
+        context for all of the API clients.
+        """
+        return self._stack.__exit__(exc_type, exc_val, exc_tb)
+
+
 
 class BaseOperator(ABC):
     """
@@ -76,6 +112,17 @@ class BaseOperator(ABC):
     def __init__(self) -> NoReturn:
         self.bos_client = BOSClient()
         self.__max_batch_size = 0
+        self._client: ApiClients | None = None
+
+    @property
+    def client(self) -> ApiClients:
+        """
+        Return the ApiClients object for this operator.
+        If it is not initialized, raise a ValueError (this should never be the case).        
+        """
+        if self._client is None:
+            raise ValueError("Attempted to access uninitialized API client")
+        return self._client
 
     @property
     @abstractmethod
@@ -98,9 +145,15 @@ def run(self) -> NoReturn:
             try:
                 options.update()
                 _update_log_level()
-                self._run()
+                with ApiClients() as _client:
+                    self._client = _client
+                    self._run()
             except Exception as e:
                 LOGGER.exception('Unhandled exception detected: %s', e)
+            finally:
+                # We have exited the context manager, so make sure to reset the client
+                # value for this operator
+                self._client = None
 
             try:
                 sleep_time = getattr(options, self.frequency_option) - (