Scheduled Commands

Cortex XSIAM guidance for scheduling commands in playbook tasks.

A command can schedule the future execution of another command. In playbook tasks using scheduled commands, the task does not proceed to the next task until it is done with all scheduled commands and there is no future execution scheduled. When a playbook waits for a command execution, it does not use a worker, since workers are only used at the time commands are executed.

You can use scheduled commands in a polling flow when a command cannot return the full result in a single execution (for example, when a remote process hasn't finished execution). Scheduled commands enable you to try the command again later and return the full results when available. For an example, see Cortex XDRIR Endpoint Isolation.

Scheduled command YAML prerequisites

• Integration - in the integration YAML, under the command root, add polling: true.
• Script - in the script YAML, in the root of the file, add polling: true

Use the polling_function decorator

The polling_function decorator can be used to avoid much of the code you would otherwise need to implement to write a polling function.

All functions implementing this decorator must always return a PollResult object.

Note

Args must be the first parameter in the function definition and call.

polling_function decorator example

In the example below, we are polling against the client.call_api function. If the API has a successful response, we return our results wrapped in a PollResult object. If the response is not successful, we return whether to continue_to_poll according to the results of the should_not_keep_polling function. A Boolean or a predicate can be passed to continue_to_poll

@polling_function('cs-falcon-sandbox-result')
def some_polling_command(args: Dict[str, Any], client: Client):
    key = get_api_id(args)
    api_response = client.call_api()
    successful_response = api_response.status_code == 200

    if successful_response:
        success_return = show_successful_response()
        return PollResult(success_return)

    else:
        error_response = CommandResults(raw_response=report_response,
                                        readable_output='API returned an error',
                                        entry_type=entryTypes['error'])

        return PollResult(continue_to_poll=lambda: not should_not_keep_polling(client, key), response=error_response)

polling_function decorator arguments

Arg	Type	Description	Default
name	str	The name of the command.	Not applicable
interval	int	How many seconds until the next run.	30
timeout	int	How long to poll until timeout.	600
poll_message	str	The message to display in the war room while polling.	Fetching Results:
polling_arg_name	str	The name of the argument to indicate polling should be done.	polling
requires_polling_arg	bool	Whether a polling argument should be expected as one of the demisto args.	True

PollResult class

Arg	Type	Description
response	any	The response of the command in the event of success, or in case of failure but Polling is false.
continue_to_poll	union [bool, Callable]	Whether to return a ScheduledCommand to the server to keep polling.
args_for_next_run	dict	The arguments to use in the next iteration. Will use the input args in case of None. Note If you are using this argument, you must add it to the YAML file with the attribute "hidden: true", so that the polling command recognizes the argument for the next run.
partial_result	CommandResults	CommandResults to return, even though we will poll again.

Note

To ignore scheduled War Room entries, add hide_polling_output as a Boolean argument to the command in the YAML file. For an example, see the cs-falcon-sandbox-scan command.

Advanced scheduled command example

In this example, we are trying to implement a command that submits a URL for analysis and then polls for the result. The proper way to implement this is to split the flow into two commands, the submit command and the find command. The find command is a polling command, and is useful on its own without the context of submit. We want to perform the submit command once and poll on the get_result command until we have a response. We will then have the submit-file command call the find-url command.

@polling_function('find-url')
def find_url_command(args: Dict[str, Any], client: Client):
    api_response = client.call_api(args.get('url')
    successful_response = api_response.status_code == 200

    if successful_response:
        success_return = show_successful_response(api_response)
        return PollResult(success_return)

    else:
        error_response = CommandResults(raw_response=report_response,
                                        readable_output='API returned an error',
                                        entry_type=entryTypes['error'])

        return PollResult(continue_to_poll=True, response=error_response)
        
def submit_url_command(args: Dict[str, Any], client: Client):
    client.submit_url(args.get('url))
    return find_url_command(args, client)

ScheduledCommand class

For scenarios the polling_function decorator does not cover, you can use the ScheduledCommand class for more advanced control over polling. ScheduledCommand is an optional class that enables scheduling commands via the command results.

Arg	Type	Description
command	str	The command that runs after next_run_in_seconds has passed.
next_run_in_seconds	int	How long to wait before executing the command. The interval between each run is determined by next_run_in_seconds, however it will never be less than 10 seconds.
args (optional)	dict	Arguments to use when executing the command.
timeout_in_seconds (optional)	int	Number of seconds until the polling sequence timeouts.

When provided to CommandResults it transforms the result into a schedule result. After the next_run_in_seconds delay, the command will be executed. The scheduled command can return another schedule result that schedules another scheduled command and so on.

The schedule sequence completes when any one of three terminating actions occur:

• Done: The integration finishes a schedule sequence by not returning a schedule result. Otherwise, the sequence continues as long as a schedule result is returned.
• Error: The schedule sequence finishes with an error when a command in the sequence returns an error result.
• Timeout (automatically handled): The schedule sequence finishes execution with a timeout error when the timeout is reached. Cortex XSIAM returns the timeout error entry automatically.

Polling scripts and ScheduledCommand

When a script with polling: true is re-run because it still has work to do (for example, items_remaining > 0), it ignores any new arguments you try to pass it. Instead, it re-runs with the original arguments from the very first time the script was executed in that sequence. This behavior is by design for polling scripts, which are meant to repeatedly check on a single, long-running task. The system assumes you want to keep checking on the same task with the same initial parameters. If you need to pass new information or manage different stages of a task, the best and most reliable way to do this is to store the data in the incident context. This ensures your script can access and update the necessary information throughout its different runs, regardless of the polling logic.

Hide scheduled War Room entries

You can prevent printing the Scheduled Entries to the War Room when there is no output. However, this is possible only for entries that are subsequent to the first entry, since the first entry is expected to provide context about the expected final result. This means the first entry is always expected to have a result, but the entries that come after it may be empty until a non-scheduled result is returned.

It is recommended to prevent printing to the War Room until the final result is available, since the schedule icon provides the scheduling context via its tooltip . To prevent War Room entries while using a ScheduledCommand, return a CommandResults with just a scheduled_command.

For example: return_results(CommandResults(scheduled_command=scheduled_command))

Polling script ScheduledCommand example

In the following example, if the status is not complete then a result with scheduled_command is returned. After interval_in_seconds seconds (60 by default), the result schedules a poll for the search status and result. This is done in the next run as well, and repeats until the status is complete.

def run_polling_command(args: dict, cmd: str, search_function: Callable, results_function: Callable):
    interval_in_secs = int(args.get('interval_in_seconds', 60))
    if 'af_cookie' not in args:
        # create new search
        command_results = search_function(args)
        outputs = command_results.outputs
        af_cookie = outputs.get('AFCookie')
        if outputs.get('Status') != 'complete':
            polling_args = {
                'af_cookie': af_cookie,
                'interval_in_seconds': interval_in_secs,
                'polling': True,
                **args
            }
            scheduled_command = ScheduledCommand(
                command=cmd,
                next_run_in_seconds=interval_in_secs,
                args=polling_args,
                timeout_in_seconds=600)
            command_results.scheduled_command = scheduled_command
            return command_results
        else:
            # continue to look for search results
            args['af_cookie'] = af_cookie
    # get search status
    command_results, status = results_function(args)
    if status != 'complete':
        # schedule next poll
        polling_args = {
            'af_cookie': args.get('af_cookie'),
            'interval_in_seconds': interval_in_secs,
            'polling': True,
            **args
        }
        scheduled_command = ScheduledCommand(
            command=cmd,
            next_run_in_seconds=interval_in_secs,
            args=polling_args,
            timeout_in_seconds=600)

        # result with scheduled_command only - no update to the war room
        command_results = CommandResults(scheduled_command=scheduled_command)
    return command_results

Use scheduled commands with demisto.executeCommand

When using demisto.executeCommand() a command or a script that returns a schedule result will not schedule a command execution. However, its result will contain the schedule metadata.

We recommend creating a new result with the ScheduledCommand class to schedule a future script execution.

Advanced users can extract the schedule metadata, and use it when scheduling the future script execution. The schedule metadata fields are: PollingCommand, NextRun, Timeout, and PollingArgs (for more information, see return_results in Python code conventions).

demisto.executeCommand example

For the autofocus-search-samples command that may return a schedule result (if it has Metadata.polling in its fields and af_cookie in its Contents) or a non-scheduled result, the wrapping script AutoFocusSearchScript can handle it as follows.

args = demisto.args()
samples_result = demisto.executeCommand('autofocus-search-samples', **args)
script_results = []
if samples_result and not isError(samples_result[0]):
    if demisto.get(samples_result[0], 'Metadata.polling'):  # result has polling metadata
        # extract the af_cookie from the results
        af_cookie = demisto.get(samples_result[0], 'Contents.AFCookie')
        if not af_cookie:
            raise ValueError('af_cookie is missing from schedule result.')
        schedule_args = {
            'af_cookie': af_cookie,
            'polling': True
        }
        schedule_command = 'AutoFocusSearchScript'
        # take the timeout and next_run from the polling fields
        schedule_timeout = demisto.get(samples_result[0], 'Timeout')
        schedule_next_run = demisto.get(samples_result[0], 'NextRun')
        scheduled_command = ScheduledCommand(
            command=schedule_command,
            next_run_in_seconds=int(schedule_next_run),
            args=schedule_args,
            timeout_in_seconds=int(schedule_timeout)
        )
        readable_output = "Autofocus search created successfully."
        script_results.append(CommandResults(
            readable_output=readable_output,
            scheduled_command=scheduled_command
        ))
    else:
        readable_output = "Autofocus search is done, see result below."
        script_results.append(CommandResults(readable_output=readable_output))
        script_results.extend(samples_result)
return_results(script_results)