flow.cylc

#!jinja2
[scheduler]
    [[events]]
        stall timeout = PT0S

[scheduling]
    cycling mode = integer
    final cycle point = 2
    [[graph]]
        P1 = remote_task[-P1] => toggler => remote_task

[runtime]
    [[remote_task]]
        platform = $(cat ${CYLC_WORKFLOW_RUN_DIR}/pretend-hall-info)

    [[toggler]]
        script = """
            # Toggle the platform between localhost and the remote host
            # using the content of a file, ${CYLC_WORKFLOW_RUN_DIR}/pretend-hall-info.
            # between localhost and the remote.

            if (( $CYLC_TASK_CYCLE_POINT % 2 == 1 )); then
                echo ${REMOTE_PLATFORM} > ${CYLC_WORKFLOW_RUN_DIR}/pretend-hall-info
                cylc message -- "changing platform to ${REMOTE_PLATFORM}"
            else
                echo "localhost" > ${CYLC_WORKFLOW_RUN_DIR}/pretend-hall-info
                cylc message -- "changing platform to localhost"
            fi
        """
        [[[environment]]]
            REMOTE_PLATFORM = {{ CYLC_TEST_PLATFORM }}