core-extra/daemon/core/configservice/manager.py

103 lines
3.3 KiB
Python

import logging
import pathlib
import pkgutil
from pathlib import Path
from core import configservices, utils
from core.configservice.base import ConfigService
from core.errors import CoreError
logger = logging.getLogger(__name__)
class ConfigServiceManager:
"""
Manager for configurable services.
"""
def __init__(self):
"""
Create a ConfigServiceManager instance.
"""
self.services: dict[str, type[ConfigService]] = {}
def get_service(self, name: str) -> type[ConfigService]:
"""
Retrieve a service by name.
:param name: name of service
:return: service class
:raises CoreError: when service is not found
"""
service_class = self.services.get(name)
if service_class is None:
raise CoreError(f"service does not exist {name}")
return service_class
def add(self, service: type[ConfigService]) -> None:
"""
Add service to manager, checking service requirements have been met.
:param service: service to add to manager
:return: nothing
:raises CoreError: when service is a duplicate or has unmet executables
"""
name = service.name
logger.debug(
"loading service: class(%s) name(%s)", service.__class__.__name__, name
)
# avoid duplicate services
if name in self.services:
raise CoreError(f"duplicate service being added: {name}")
# validate dependent executables are present
for executable in service.executables:
try:
utils.which(executable, required=True)
except CoreError as e:
raise CoreError(f"config service({service.name}): {e}")
# make service available
self.services[name] = service
def load_locals(self) -> list[str]:
"""
Search and add config service from local core module.
:return: list of errors when loading services
"""
errors = []
for module_info in pkgutil.walk_packages(
configservices.__path__, f"{configservices.__name__}."
):
services = utils.load_module(module_info.name, ConfigService)
for service in services:
try:
self.add(service)
except CoreError as e:
errors.append(service.name)
logger.debug("not loading config service(%s): %s", service.name, e)
return errors
def load(self, path: Path) -> list[str]:
"""
Search path provided for config services and add them for being managed.
:param path: path to search configurable services
:return: list errors when loading services
"""
path = pathlib.Path(path)
subdirs = [x for x in path.iterdir() if x.is_dir()]
subdirs.append(path)
service_errors = []
for subdir in subdirs:
logger.debug("loading config services from: %s", subdir)
services = utils.load_classes(subdir, ConfigService)
for service in services:
try:
self.add(service)
except CoreError as e:
service_errors.append(service.name)
logger.debug("not loading service(%s): %s", service.name, e)
return service_errors