""" Simple example for a user-defined service. """ from core.services.coreservices import CoreService, ServiceMode class MyService(CoreService): """ Custom CORE Service :var str name: name used as a unique ID for this service and is required, no spaces :var str group: allows you to group services within the GUI under a common name :var tuple executables: executables this service depends on to function, if executable is not on the path, service will not be loaded :var tuple dependencies: services that this service depends on for startup, tuple of service names :var tuple dirs: directories that this service will create within a node :var tuple configs: files that this service will generate, without a full path this file goes in the node's directory e.g. /tmp/pycore.12345/n1.conf/myfile :var tuple startup: commands used to start this service, any non-zero exit code will cause a failure :var tuple validate: commands used to validate that a service was started, any non-zero exit code will cause a failure :var ServiceMode validation_mode: validation mode, used to determine startup success. NON_BLOCKING - runs startup commands, and validates success with validation commands BLOCKING - runs startup commands, and validates success with the startup commands themselves TIMER - runs startup commands, and validates success by waiting for "validation_timer" alone :var int validation_timer: time in seconds for a service to wait for validation, before determining success in TIMER/NON_BLOCKING modes. :var float validation_validation_period: period in seconds to wait before retrying validation, only used in NON_BLOCKING mode :var tuple shutdown: shutdown commands to stop this service """ name = "MyService" group = "Utility" executables = () dependencies = () dirs = () configs = ("myservice1.sh", "myservice2.sh") startup = tuple(f"sh {x}" for x in configs) validate = () validation_mode = ServiceMode.NON_BLOCKING validation_timer = 5 validation_period = 0.5 shutdown = () @classmethod def on_load(cls): """ Provides a way to run some arbitrary logic when the service is loaded, possibly to help facilitate dynamic settings for the environment. :return: nothing """ pass @classmethod def get_configs(cls, node): """ Provides a way to dynamically generate the config files from the node a service will run. Defaults to the class definition and can be left out entirely if not needed. :param node: core node that the service is being ran on :return: tuple of config files to create """ return cls.configs @classmethod def generate_config(cls, node, filename): """ Returns a string representation for a file, given the node the service is starting on the config filename that this information will be used for. This must be defined, if "configs" are defined. :param node: core node that the service is being ran on :param str filename: configuration file to generate :return: configuration file content :rtype: str """ cfg = "#!/bin/sh\n" if filename == cls.configs[0]: cfg += "# auto-generated by MyService (sample.py)\n" for iface in node.get_ifaces(): cfg += f'echo "Node {node.name} has interface {iface.name}"\n' elif filename == cls.configs[1]: cfg += "echo hello" return cfg @classmethod def get_startup(cls, node): """ Provides a way to dynamically generate the startup commands from the node a service will run. Defaults to the class definition and can be left out entirely if not needed. :param node: core node that the service is being ran on :return: tuple of startup commands to run """ return cls.startup @classmethod def get_validate(cls, node): """ Provides a way to dynamically generate the validate commands from the node a service will run. Defaults to the class definition and can be left out entirely if not needed. :param node: core node that the service is being ran on :return: tuple of commands to validate service startup with """ return cls.validate