feat(helper): Rework graceful terminator

* Rename module
* Silence pylint error
* Add method for cicd mode termination

duties/helper/terminate.py

@@ -0,0 +1,51 @@
+"""Helper module for graceful shutdown
+"""
+
+import signal
+from sys import exit as sys_exit
+from typing import Any, List
+
+from cli.arguments import Mode
+from fetcher.data_types import ValidatorDuty
+
+
+# pylint: disable=too-few-public-methods
+class GracefulTerminator:
+    """Helper class for graceful termination"""
+
+    def __init__(self, max_number_of_cicd_cycles: int) -> None:
+        self.kill_now = False
+        self.__cicd_cycle_counter = 0
+        self.__max_number_of_cicd_cycles = max_number_of_cicd_cycles
+        signal.signal(signal.SIGINT, self.__terminate_gracefully)
+        signal.signal(signal.SIGTERM, self.__terminate_gracefully)
+
+    def __terminate_gracefully(self, *_: Any) -> None:
+        """Main method to terminate program gracefully"""
+        self.kill_now = True
+
+    def terminate_in_cicd_mode(
+        self, running_mode: Mode, duties: List[ValidatorDuty]
+    ) -> None:
+        """Terminates the running application in dependence of the mode and
+        the duties which could be found for the provided validators
+
+        Args:
+            running_mode (Mode): Running mode of eth-duties
+            duties (List[ValidatorDuty]): List of fetched validator duties
+        """
+        match running_mode:
+            case Mode.CICD_EXIT:
+                if len(duties) > 0:
+                    sys_exit(1)
+                sys_exit(0)
+            case Mode.CICD_WAIT:
+                if len(duties) == 0:
+                    sys_exit(0)
+                if self.__cicd_cycle_counter >= self.__max_number_of_cicd_cycles:
+                    sys_exit(1)
+            case Mode.EXIT_GRACEFULLY:
+                sys_exit(0)
+            case _:
+                pass
+        self.__cicd_cycle_counter += 1