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

497 lines
16 KiB
Python

import abc
import enum
import inspect
import logging
import time
from dataclasses import dataclass
from pathlib import Path
from typing import Any, Dict, List, Optional
from mako import exceptions
from mako.lookup import TemplateLookup
from mako.template import Template
from core.config import Configuration
from core.errors import CoreCommandError, CoreError
from core.nodes.base import CoreNode
logger = logging.getLogger(__name__)
TEMPLATES_DIR: str = "templates"
def get_template_path(file_path: Path) -> str:
"""
Utility to convert a given file path to a valid template path format.
:param file_path: file path to convert
:return: template path
"""
if file_path.is_absolute():
template_path = str(file_path.relative_to("/"))
else:
template_path = str(file_path)
return template_path
class ConfigServiceMode(enum.Enum):
BLOCKING = 0
NON_BLOCKING = 1
TIMER = 2
class ConfigServiceBootError(Exception):
pass
class ConfigServiceTemplateError(Exception):
pass
@dataclass
class ShadowDir:
path: str
src: Optional[str] = None
templates: bool = False
has_node_paths: bool = False
class ConfigService(abc.ABC):
"""
Base class for creating configurable services.
"""
# validation period in seconds, how frequent validation is attempted
validation_period: float = 0.5
# time to wait in seconds for determining if service started successfully
validation_timer: int = 5
# directories to shadow and copy files from
shadow_directories: List[ShadowDir] = []
def __init__(self, node: CoreNode) -> None:
"""
Create ConfigService instance.
:param node: node this service is assigned to
"""
self.node: CoreNode = node
class_file = inspect.getfile(self.__class__)
templates_path = Path(class_file).parent.joinpath(TEMPLATES_DIR)
self.templates: TemplateLookup = TemplateLookup(directories=templates_path)
self.config: Dict[str, Configuration] = {}
self.custom_templates: Dict[str, str] = {}
self.custom_config: Dict[str, str] = {}
configs = self.default_configs[:]
self._define_config(configs)
@staticmethod
def clean_text(text: str) -> str:
"""
Returns space stripped text for string literals, while keeping space
indentations.
:param text: text to clean
:return: cleaned text
"""
return inspect.cleandoc(text)
@property
@abc.abstractmethod
def name(self) -> str:
raise NotImplementedError
@property
@abc.abstractmethod
def group(self) -> str:
raise NotImplementedError
@property
@abc.abstractmethod
def directories(self) -> List[str]:
raise NotImplementedError
@property
@abc.abstractmethod
def files(self) -> List[str]:
raise NotImplementedError
@property
@abc.abstractmethod
def default_configs(self) -> List[Configuration]:
raise NotImplementedError
@property
@abc.abstractmethod
def modes(self) -> Dict[str, Dict[str, str]]:
raise NotImplementedError
@property
@abc.abstractmethod
def executables(self) -> List[str]:
raise NotImplementedError
@property
@abc.abstractmethod
def dependencies(self) -> List[str]:
raise NotImplementedError
@property
@abc.abstractmethod
def startup(self) -> List[str]:
raise NotImplementedError
@property
@abc.abstractmethod
def validate(self) -> List[str]:
raise NotImplementedError
@property
@abc.abstractmethod
def shutdown(self) -> List[str]:
raise NotImplementedError
@property
@abc.abstractmethod
def validation_mode(self) -> ConfigServiceMode:
raise NotImplementedError
def start(self) -> None:
"""
Creates services files/directories, runs startup, and validates based on
validation mode.
:return: nothing
:raises ConfigServiceBootError: when there is an error starting service
"""
logger.info("node(%s) service(%s) starting...", self.node.name, self.name)
self.create_shadow_dirs()
self.create_dirs()
self.create_files()
wait = self.validation_mode == ConfigServiceMode.BLOCKING
self.run_startup(wait)
if not wait:
if self.validation_mode == ConfigServiceMode.TIMER:
self.wait_validation()
else:
self.run_validation()
def stop(self) -> None:
"""
Stop service using shutdown commands.
:return: nothing
"""
for cmd in self.shutdown:
try:
self.node.cmd(cmd)
except CoreCommandError:
logger.exception(
f"node({self.node.name}) service({self.name}) "
f"failed shutdown: {cmd}"
)
def restart(self) -> None:
"""
Restarts service by running stop and then start.
:return: nothing
"""
self.stop()
self.start()
def create_shadow_dirs(self) -> None:
"""
Creates a shadow of a host system directory recursively
to be mapped and live within a node.
:return: nothing
:raises CoreError: when there is a failure creating a directory or file
"""
for shadow_dir in self.shadow_directories:
# setup shadow and src paths, using node unique paths when configured
shadow_path = Path(shadow_dir.path)
if shadow_dir.src is None:
src_path = shadow_path
else:
src_path = Path(shadow_dir.src)
if shadow_dir.has_node_paths:
src_path = src_path / self.node.name
# validate shadow and src paths
if not shadow_path.is_absolute():
raise CoreError(f"shadow dir({shadow_path}) is not absolute")
if not src_path.is_absolute():
raise CoreError(f"shadow source dir({src_path}) is not absolute")
if not src_path.is_dir():
raise CoreError(f"shadow source dir({src_path}) does not exist")
# create root of the shadow path within node
logger.info(
"node(%s) creating shadow directory(%s) src(%s) node paths(%s) "
"templates(%s)",
self.node.name,
shadow_path,
src_path,
shadow_dir.has_node_paths,
shadow_dir.templates,
)
self.node.create_dir(shadow_path)
# find all directories and files to create
dir_paths = []
file_paths = []
for path in src_path.rglob("*"):
shadow_src_path = shadow_path / path.relative_to(src_path)
if path.is_dir():
dir_paths.append(shadow_src_path)
else:
file_paths.append((path, shadow_src_path))
# create all directories within node
for path in dir_paths:
self.node.create_dir(path)
# create all files within node, from templates when configured
data = self.data()
templates = TemplateLookup(directories=src_path)
for path, dst_path in file_paths:
if shadow_dir.templates:
template = templates.get_template(path.name)
rendered = self._render(template, data)
self.node.create_file(dst_path, rendered)
else:
self.node.copy_file(path, dst_path)
def create_dirs(self) -> None:
"""
Creates directories for service.
:return: nothing
:raises CoreError: when there is a failure creating a directory
"""
logger.debug("creating config service directories")
for directory in sorted(self.directories):
dir_path = Path(directory)
try:
self.node.create_dir(dir_path)
except (CoreCommandError, CoreError):
raise CoreError(
f"node({self.node.name}) service({self.name}) "
f"failure to create service directory: {directory}"
)
def data(self) -> Dict[str, Any]:
"""
Returns key/value data, used when rendering file templates.
:return: key/value template data
"""
return {}
def set_template(self, name: str, template: str) -> None:
"""
Store custom template to render for a given file.
:param name: file to store custom template for
:param template: custom template to render
:return: nothing
"""
self.custom_templates[name] = template
def get_text_template(self, name: str) -> str:
"""
Retrieves text based template for files that do not have a file based template.
:param name: name of file to get template for
:return: template to render
"""
raise CoreError(f"service({self.name}) unknown template({name})")
def get_templates(self) -> Dict[str, str]:
"""
Retrieves mapping of file names to templates for all cases, which
includes custom templates, file templates, and text templates.
:return: mapping of files to templates
"""
templates = {}
for file in self.files:
file_path = Path(file)
template_path = get_template_path(file_path)
if file in self.custom_templates:
template = self.custom_templates[file]
template = self.clean_text(template)
elif self.templates.has_template(template_path):
template = self.templates.get_template(template_path).source
else:
try:
template = self.get_text_template(file)
except Exception as e:
raise ConfigServiceTemplateError(
f"node({self.node.name}) service({self.name}) file({file}) "
f"failure getting template: {e}"
)
template = self.clean_text(template)
templates[file] = template
return templates
def create_files(self) -> None:
"""
Creates service files inside associated node.
:return: nothing
"""
data = self.data()
for file in sorted(self.files):
logger.debug(
"node(%s) service(%s) template(%s)", self.node.name, self.name, file
)
file_path = Path(file)
template_path = get_template_path(file_path)
if file in self.custom_templates:
text = self.custom_templates[file]
rendered = self.render_text(text, data)
elif self.templates.has_template(template_path):
rendered = self.render_template(template_path, data)
else:
try:
text = self.get_text_template(file)
except Exception as e:
raise ConfigServiceTemplateError(
f"node({self.node.name}) service({self.name}) file({file}) "
f"failure getting template: {e}"
)
rendered = self.render_text(text, data)
self.node.create_file(file_path, rendered)
def run_startup(self, wait: bool) -> None:
"""
Run startup commands for service on node.
:param wait: wait successful command exit status when True, ignore status
otherwise
:return: nothing
:raises ConfigServiceBootError: when a command that waits fails
"""
for cmd in self.startup:
try:
self.node.cmd(cmd, wait=wait)
except CoreCommandError as e:
raise ConfigServiceBootError(
f"node({self.node.name}) service({self.name}) failed startup: {e}"
)
def wait_validation(self) -> None:
"""
Waits for a period of time to consider service started successfully.
:return: nothing
"""
time.sleep(self.validation_timer)
def run_validation(self) -> None:
"""
Runs validation commands for service on node.
:return: nothing
:raises ConfigServiceBootError: if there is a validation failure
"""
start = time.monotonic()
cmds = self.validate[:]
index = 0
while cmds:
cmd = cmds[index]
try:
self.node.cmd(cmd)
del cmds[index]
index += 1
except CoreCommandError:
logger.debug(
f"node({self.node.name}) service({self.name}) "
f"validate command failed: {cmd}"
)
time.sleep(self.validation_period)
if cmds and time.monotonic() - start > self.validation_timer:
raise ConfigServiceBootError(
f"node({self.node.name}) service({self.name}) failed to validate"
)
def _render(self, template: Template, data: Dict[str, Any] = None) -> str:
"""
Renders template providing all associated data to template.
:param template: template to render
:param data: service specific defined data for template
:return: rendered template
"""
if data is None:
data = {}
return template.render_unicode(
node=self.node, config=self.render_config(), **data
)
def render_text(self, text: str, data: Dict[str, Any] = None) -> str:
"""
Renders text based template providing all associated data to template.
:param text: text to render
:param data: service specific defined data for template
:return: rendered template
"""
text = self.clean_text(text)
try:
template = Template(text)
return self._render(template, data)
except Exception:
raise CoreError(
f"node({self.node.name}) service({self.name}) "
f"{exceptions.text_error_template().render_unicode()}"
)
def render_template(self, template_path: str, data: Dict[str, Any] = None) -> str:
"""
Renders file based template providing all associated data to template.
:param template_path: path of file to render
:param data: service specific defined data for template
:return: rendered template
"""
try:
template = self.templates.get_template(template_path)
return self._render(template, data)
except Exception:
raise CoreError(
f"node({self.node.name}) service({self.name}) file({template_path})"
f"{exceptions.text_error_template().render_template()}"
)
def _define_config(self, configs: List[Configuration]) -> None:
"""
Initializes default configuration data.
:param configs: configs to initialize
:return: nothing
"""
for config in configs:
self.config[config.id] = config
def render_config(self) -> Dict[str, str]:
"""
Returns configuration data key/value pairs for rendering a template.
:return: nothing
"""
if self.custom_config:
return self.custom_config
else:
return {k: v.default for k, v in self.config.items()}
def set_config(self, data: Dict[str, str]) -> None:
"""
Set configuration data from key/value pairs.
:param data: configuration key/values to set
:return: nothing
:raise CoreError: when an unknown configuration value is given
"""
for key, value in data.items():
if key not in self.config:
raise CoreError(f"unknown config: {key}")
self.custom_config[key] = value