core/homeassistant/util/ruamel_yaml.py

153 lines
4.7 KiB
Python

"""ruamel.yaml utility functions."""
from __future__ import annotations
from collections import OrderedDict
from contextlib import suppress
import logging
import os
from os import O_CREAT, O_TRUNC, O_WRONLY, stat_result
from typing import Dict, List, Union
import ruamel.yaml
from ruamel.yaml import YAML # type: ignore
from ruamel.yaml.compat import StringIO
from ruamel.yaml.constructor import SafeConstructor
from ruamel.yaml.error import YAMLError
from homeassistant.exceptions import HomeAssistantError
from homeassistant.util.yaml import secret_yaml
_LOGGER = logging.getLogger(__name__)
JSON_TYPE = Union[List, Dict, str] # pylint: disable=invalid-name
class ExtSafeConstructor(SafeConstructor):
"""Extended SafeConstructor."""
name: str | None = None
class UnsupportedYamlError(HomeAssistantError):
"""Unsupported YAML."""
class WriteError(HomeAssistantError):
"""Error writing the data."""
def _include_yaml(
constructor: ExtSafeConstructor, node: ruamel.yaml.nodes.Node
) -> JSON_TYPE:
"""Load another YAML file and embeds it using the !include tag.
Example:
device_tracker: !include device_tracker.yaml
"""
if constructor.name is None:
raise HomeAssistantError(
"YAML include error: filename not set for %s" % node.value
)
fname = os.path.join(os.path.dirname(constructor.name), node.value)
return load_yaml(fname, False)
def _yaml_unsupported(
constructor: ExtSafeConstructor, node: ruamel.yaml.nodes.Node
) -> None:
raise UnsupportedYamlError(
f"Unsupported YAML, you can not use {node.tag} in "
f"{os.path.basename(constructor.name or '(None)')}"
)
def object_to_yaml(data: JSON_TYPE) -> str:
"""Create yaml string from object."""
yaml = YAML(typ="rt")
yaml.indent(sequence=4, offset=2)
stream = StringIO()
try:
yaml.dump(data, stream)
result: str = stream.getvalue()
return result
except YAMLError as exc:
_LOGGER.error("YAML error: %s", exc)
raise HomeAssistantError(exc) from exc
def yaml_to_object(data: str) -> JSON_TYPE:
"""Create object from yaml string."""
yaml = YAML(typ="rt")
try:
result: list | dict | str = yaml.load(data)
return result
except YAMLError as exc:
_LOGGER.error("YAML error: %s", exc)
raise HomeAssistantError(exc) from exc
def load_yaml(fname: str, round_trip: bool = False) -> JSON_TYPE:
"""Load a YAML file."""
if round_trip:
yaml = YAML(typ="rt")
yaml.preserve_quotes = True
else:
if ExtSafeConstructor.name is None:
ExtSafeConstructor.name = fname
yaml = YAML(typ="safe")
yaml.Constructor = ExtSafeConstructor
try:
with open(fname, encoding="utf-8") as conf_file:
# If configuration file is empty YAML returns None
# We convert that to an empty dict
return yaml.load(conf_file) or OrderedDict()
except YAMLError as exc:
_LOGGER.error("YAML error in %s: %s", fname, exc)
raise HomeAssistantError(exc) from exc
except UnicodeDecodeError as exc:
_LOGGER.error("Unable to read file %s: %s", fname, exc)
raise HomeAssistantError(exc) from exc
def save_yaml(fname: str, data: JSON_TYPE) -> None:
"""Save a YAML file."""
yaml = YAML(typ="rt")
yaml.indent(sequence=4, offset=2)
tmp_fname = f"{fname}__TEMP__"
try:
try:
file_stat = os.stat(fname)
except OSError:
file_stat = stat_result((0o644, -1, -1, -1, -1, -1, -1, -1, -1, -1))
with open(
os.open(tmp_fname, O_WRONLY | O_CREAT | O_TRUNC, file_stat.st_mode),
"w",
encoding="utf-8",
) as temp_file:
yaml.dump(data, temp_file)
os.replace(tmp_fname, fname)
if hasattr(os, "chown") and file_stat.st_ctime > -1:
with suppress(OSError):
os.chown(fname, file_stat.st_uid, file_stat.st_gid)
except YAMLError as exc:
_LOGGER.error(str(exc))
raise HomeAssistantError(exc) from exc
except OSError as exc:
_LOGGER.exception("Saving YAML file %s failed: %s", fname, exc)
raise WriteError(exc) from exc
finally:
if os.path.exists(tmp_fname):
try:
os.remove(tmp_fname)
except OSError as exc:
# If we are cleaning up then something else went wrong, so
# we should suppress likely follow-on errors in the cleanup
_LOGGER.error("YAML replacement cleanup failed: %s", exc)
ExtSafeConstructor.add_constructor("!secret", secret_yaml)
ExtSafeConstructor.add_constructor("!include", _include_yaml)
ExtSafeConstructor.add_constructor(None, _yaml_unsupported)