Spaces:
Running
Running
File size: 1,331 Bytes
4bdb245 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 |
import os
import re
import typing
from typing import Any, TextIO
from yaml import SafeLoader
_env_replace_matcher = re.compile(r"\$\{(\w|_)+:?.*}")
@typing.no_type_check # pyaml does not have good hints, everything is Any
def load_yaml_with_envvars(
stream: TextIO, environ: dict[str, Any] = os.environ
) -> dict[str, Any]:
"""Load yaml file with environment variable expansion.
The pattern ${VAR} or ${VAR:default} will be replaced with
the value of the environment variable.
"""
loader = SafeLoader(stream)
def load_env_var(_, node) -> str:
"""Extract the matched value, expand env variable, and replace the match."""
value = str(node.value).removeprefix("${").removesuffix("}")
split = value.split(":", 1)
env_var = split[0]
value = environ.get(env_var)
default = None if len(split) == 1 else split[1]
if value is None and default is None:
raise ValueError(
f"Environment variable {env_var} is not set and not default was provided"
)
return value or default
loader.add_implicit_resolver("env_var_replacer", _env_replace_matcher, None)
loader.add_constructor("env_var_replacer", load_env_var)
try:
return loader.get_single_data()
finally:
loader.dispose()
|