def _usable_shared_cf_stack_exists()

in common/sagemaker_rl/orchestrator/resource_manager.py [0:0]

• 62 lines of code
• 13 McCabe index (conditional complexity)

    def _usable_shared_cf_stack_exists(self):
        """Check if the shared cf stack exist and is usable

        Returns:
            bool: Whether the shared cf stack is usable
        """
        # we can remove this logic, and have checks only on CF stack exists,
        # CF stack in one of [CREATE|UPDATE|ROLLBACK]_COMPLETE state
        try:
            stack_name = self.shared_resource_stack_name
            response = self.cf_client.describe_stacks(StackName=stack_name)["Stacks"]
            if len(response) == 0:
                return False
        except Exception as e:
            if "UnauthorizedOperation" in str(e):
                raise Exception(
                    "You are unauthorized to describe a CloudFormation Stack. Please update your Role with "
                    " appropriate permissions."
                )
            elif "ValidationError" in str(e):
                # stack doesn't exists
                return False
            else:
                raise e

        stack_details = response[0]
        stack_status = stack_details["StackStatus"]
        if stack_status in ["UPDATE_COMPLETE", "CREATE_COMPLETE"]:
            return True
        elif stack_status in ["DELETE_COMPLETE"]:
            return False
        elif stack_status in ["ROLLBACK_COMPLETE"]:
            logger.error(
                f"Stack with name {stack_name} is in {stack_status} state! Please delete/ stabilize/ or "
                "or update Config.yaml to create a new stack"
            )
            raise Exception(
                f"A Cloudformation Stack with name {stack_name}, already exists in {stack_status} State. "
                f"Please debug/ or delete the stack here: {self._get_cf_stack_events_link()}"
            )
        elif "FAILED" in stack_status:
            logger.error(
                f"Stack with name {stack_name} in {stack_status} state! Please delete the stack"
                " or update Config.yaml to create a new stack"
            )
            raise Exception(
                f"A Cloudformation Stack with name {stack_name}, already exists in {stack_status} State. "
                f"Please debug/ or delete the stack here: {self._get_cf_stack_events_link()}"
            )
        elif "DELETE" in stack_status:
            # already checked DELETE_COMPLETE above
            logger.error(
                "Stack with name {} is in {} state! Cannot continue further!"
                " Please wait for the delete to complete".format(stack_name, stack_status)
            )
            raise Exception(
                f"A Cloudformation Stack with name {stack_name}, already exists in {stack_status} State. "
                f"Please retry after the stack gets Deleted/or debug the stack here: {self._get_cf_stack_events_link()}"
            )
        elif "CREATE" in stack_status:
            # one of the create statuses!
            logger.info("Stack with name {} exists in {} state".format(stack_name, stack_status))
            logger.warn("Waiting for stack to get to CREATE_COMPLETE state....")
            self._wait_for_cf_stack_create_to_complete()
            return True
        else:
            # assume stack in modifying. wait for it to goto
            logger.info(
                "Stack in {} state. Waiting for it's to end in successful state...".format(
                    stack_status
                )
            )
            self._wait_for_cf_stack_update_to_complete()
            return True