systemlink-file-subscriber-example-service

SystemLink service example for subscribing to file broadcasts

SystemLink allows launching python projects as SystemLink services. The SystemLink service manager detects new service descriptors which instruct the service manager which executables to launch. The service manager is capable of launching C# DLLs which implement the ManagedServiceBase class, but can also launch external executable applications which implement the ManagedServiceBase as well. In this case, the ManagedServiceBase is provided by the SystemLink python SDK, and provides the control messages and configuration through the Service Manager.

1. Initial Setup

Copy the files in the two base folders (ProgramData and Program Files) to your SystemLink server.

2. Restart the SystemLink Service Manager

Using the SystemLink Server Configuration application, click restart to re-launch the application. The service descriptors are read only once when the service starts, so the Service Manager must be restarted to detect newly installed services.

3. Customize the File Subscriber example service

The File Subscriber is a basic example that can be modified to perform tasks when a file broadcast message is received. The example implementation shows how the service subscribes to specific messages and defines callbacks to run when those events occur.

Modify the /Program Files/Skyline/FileSubscriberExample/systemlink/filesubscriberexampleservice/handlers/amqp_handlers.py file's file_available_broadcast method to insert your custom code.

def file_available_broadcast(
        self,
        generic_message: GenericMessage,
    ):
    """
    :param generic_message: An object representing the AMQP message.
    """
    # Log that the broadcast was received.
    # This is logged at ERROR level so that it will appear in the log.
    # Logging level should be decreased or removed once implementation and debugging is completed.
    # Optionally, logging could be done to a tracepoint instead.
    LOGGER.error('received file available broadcast!')
    # TODO: Customize the code here to perform your task