"""Copy of ``awscli.customizations.cloudformation.yamlhelper.py``."""
# Copyright 2012-2015 Amazon.com, Inc. or its affiliates. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"). You
# may not use this file except in compliance with the License. A copy of
# the License is located at
#
# http://aws.amazon.com/apache2.0/
#
# or in the "license" file accompanying this file. This file is
# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
# ANY KIND, either express or implied. See the License for the specific
# language governing permissions and limitations under the License.
from __future__ import annotations
import json
from typing import Any, Dict, MutableMapping, MutableSequence, cast
import yaml
[docs]def intrinsics_multi_constructor( # pylint: disable=unused-argument
loader: yaml.Loader, tag_prefix: str, node: yaml.Node
) -> Dict[str, Any]:
"""YAML constructor to parse CloudFormation intrinsics.
This will return a dictionary with key being the intrinsic name
"""
# Get the actual tag name excluding the first exclamation
tag = node.tag[1:]
# Some intrinsic functions doesn't support prefix "Fn::"
prefix = "Fn::"
if tag in ["Ref", "Condition"]:
prefix = ""
cfntag = prefix + tag
if tag == "GetAtt" and isinstance(node.value, str):
# ShortHand notation for !GetAtt accepts Resource.Attribute format
# while the standard notation is to use an array
# [Resource, Attribute]. Convert shorthand to standard format
value = node.value.split(".", 1)
elif isinstance(node, yaml.ScalarNode):
# Value of this node is scalar
value = loader.construct_scalar(node)
elif isinstance(node, yaml.SequenceNode):
# Value of this node is an array (Ex: [1,2])
value = cast(MutableSequence[Any], loader.construct_sequence(node))
else:
# Value of this node is an mapping (ex: {foo: bar})
value = cast(MutableMapping[Any, Any], loader.construct_mapping(node)) # type: ignore
return {cfntag: value}
[docs]def yaml_dump(dict_to_dump: Dict[str, Any]) -> str:
"""Dump the dictionary as a YAML document."""
return yaml.safe_dump(dict_to_dump, default_flow_style=False)
[docs]def yaml_parse(yamlstr: str) -> Dict[str, Any]:
"""Parse a yaml string."""
try:
# PyYAML doesn't support json as well as it should, so if the input
# is actually just json it is better to parse it with the standard
# json parser.
return json.loads(yamlstr)
except ValueError:
yaml.SafeLoader.add_multi_constructor("!", intrinsics_multi_constructor)
return yaml.safe_load(yamlstr)