sanic/sanic/utils.py
Thomas Grainger 48f8b37b74
support app factory patten in CLI (#2157)
* support app factory patten in CLI

* Update sanic/__main__.py

* fix mypy errors

* Update mypy further

* Update sanic/utils.py

* Update sanic/utils.py

* support hypercorn/gunicorn style 'asgi.app:create_app()'

* add test for app factory
2021-06-09 12:05:56 +03:00

133 lines
4.3 KiB
Python

import types
from importlib.util import module_from_spec, spec_from_file_location
from os import environ as os_environ
from pathlib import Path
from re import findall as re_findall
from typing import Union
from sanic.exceptions import LoadFileException, PyFileError
from sanic.helpers import import_string
def str_to_bool(val: str) -> bool:
"""Takes string and tries to turn it into bool as human would do.
If val is in case insensitive (
"y", "yes", "yep", "yup", "t",
"true", "on", "enable", "enabled", "1"
) returns True.
If val is in case insensitive (
"n", "no", "f", "false", "off", "disable", "disabled", "0"
) returns False.
Else Raise ValueError."""
val = val.lower()
if val in {
"y",
"yes",
"yep",
"yup",
"t",
"true",
"on",
"enable",
"enabled",
"1",
}:
return True
elif val in {"n", "no", "f", "false", "off", "disable", "disabled", "0"}:
return False
else:
raise ValueError(f"Invalid truth value {val}")
def load_module_from_file_location(
location: Union[bytes, str, Path], encoding: str = "utf8", *args, **kwargs
): # noqa
"""Returns loaded module provided as a file path.
:param args:
Coresponds to importlib.util.spec_from_file_location location
parameters,but with this differences:
- It has to be of a string or bytes type.
- You can also use here environment variables
in format ${some_env_var}.
Mark that $some_env_var will not be resolved as environment variable.
:encoding:
If location parameter is of a bytes type, then use this encoding
to decode it into string.
:param args:
Coresponds to the rest of importlib.util.spec_from_file_location
parameters.
:param kwargs:
Coresponds to the rest of importlib.util.spec_from_file_location
parameters.
For example You can:
some_module = load_module_from_file_location(
"some_module_name",
"/some/path/${some_env_var}"
)
"""
if isinstance(location, bytes):
location = location.decode(encoding)
if isinstance(location, Path) or "/" in location or "$" in location:
if not isinstance(location, Path):
# A) Check if location contains any environment variables
# in format ${some_env_var}.
env_vars_in_location = set(re_findall(r"\${(.+?)}", location))
# B) Check these variables exists in environment.
not_defined_env_vars = env_vars_in_location.difference(
os_environ.keys()
)
if not_defined_env_vars:
raise LoadFileException(
"The following environment variables are not set: "
f"{', '.join(not_defined_env_vars)}"
)
# C) Substitute them in location.
for env_var in env_vars_in_location:
location = location.replace(
"${" + env_var + "}", os_environ[env_var]
)
location = str(location)
if ".py" in location:
name = location.split("/")[-1].split(".")[
0
] # get just the file name without path and .py extension
_mod_spec = spec_from_file_location(
name, location, *args, **kwargs
)
assert _mod_spec is not None # type assertion for mypy
module = module_from_spec(_mod_spec)
_mod_spec.loader.exec_module(module) # type: ignore
else:
module = types.ModuleType("config")
module.__file__ = str(location)
try:
with open(location) as config_file:
exec( # nosec
compile(config_file.read(), location, "exec"),
module.__dict__,
)
except IOError as e:
e.strerror = "Unable to load configuration file (e.strerror)"
raise
except Exception as e:
raise PyFileError(location) from e
return module
else:
try:
return import_string(location)
except ValueError:
raise IOError("Unable to load configuration %s" % str(location))