import os
from yarl import URL
from typing import Any, Callable, Iterable, Tuple, Union
__all__ = [
'get_config',
'set_config',
'APIConfig',
]
_config = None
[docs]def get_env(key: str,
default: Any = None,
clean: Callable[[str], Any] = lambda v: v):
'''
Retrieves a configuration value from the environment variables.
The given *key* is uppercased and prefixed by ``"BACKEND_"`` and then
``"SORNA_"`` if the former does not exist.
:param key: The key name.
:param default: The default value returned when there is no corresponding
environment variable.
:param clean: A single-argument function that is applied to the result of lookup
(in both successes and the default value for failures).
The default is returning the value as-is.
:returns: The value processed by the *clean* function.
'''
key = key.upper()
v = os.environ.get('BACKEND_' + key)
if v is None:
v = os.environ.get('SORNA_' + key)
if v is None:
if default is None:
raise KeyError(key)
v = default
return clean(v)
def bool_env(v: str) -> bool:
v = v.lower()
if v in ('y', 'yes', 't', 'true', '1'):
return True
if v in ('n', 'no', 'f', 'false', '0'):
return False
raise ValueError('Unrecognized value of boolean environment variable', v)
def _clean_url(v):
v = v if isinstance(v, URL) else URL(v)
if not v.is_absolute():
raise ValueError('URL must be absolute.')
return v
def _clean_tokens(v):
if isinstance(v, str):
if not v:
return tuple()
return tuple(v.split(','))
return tuple(iter(v))
[docs]class APIConfig:
'''
Represents a set of API client configurations.
The access key and secret key are mandatory -- they must be set in either
environment variables or as the explicit arguments.
:param endpoint: The URL prefix to make API requests via HTTP/HTTPS.
:param version: The API protocol version.
:param user_agent: A custom user-agent string which is sent to the API
server as a ``User-Agent`` HTTP header.
:param access_key: The API access key.
:param secret_key: The API secret key.
:param hash_type: The hash type to generate per-request authentication
signatures.
:param vfolder_mounts: A list of vfolder names (that must belong to the given
access key) to be automatically mounted upon any
:func:`Kernel.get_or_create()
<ai.backend.client.kernel.Kernel.get_or_create>` calls.
'''
DEFAULTS = {
'endpoint': 'https://api.backend.ai',
'version': 'v4.20190315',
'hash_type': 'sha256',
}
'''
The default values except the access and secret keys.
'''
def __init__(self, *,
endpoint: Union[URL, str] = None,
version: str = None,
user_agent: str = None,
access_key: str = None,
secret_key: str = None,
hash_type: str = None,
vfolder_mounts: Iterable[str] = None,
skip_sslcert_validation: bool = None) -> None:
from . import get_user_agent # noqa; to avoid circular imports
self._endpoint = (
_clean_url(endpoint) if endpoint else
get_env('ENDPOINT', self.DEFAULTS['endpoint'], clean=_clean_url))
self._version = version if version else self.DEFAULTS['version']
self._user_agent = user_agent if user_agent else get_user_agent()
self._access_key = access_key if access_key else get_env('ACCESS_KEY')
self._secret_key = secret_key if secret_key else get_env('SECRET_KEY')
self._hash_type = hash_type.lower() if hash_type else \
self.DEFAULTS['hash_type']
arg_vfolders = set(vfolder_mounts) if vfolder_mounts else set()
env_vfolders = set(get_env('VFOLDER_MOUNTS', [], clean=_clean_tokens))
self._vfolder_mounts = [*(arg_vfolders | env_vfolders)]
# prefer the argument flag and fallback to env if the flag is not set.
self._skip_sslcert_validation = (skip_sslcert_validation
if skip_sslcert_validation else
get_env('SKIP_SSLCERT_VALIDATION', default='no', clean=bool_env))
@property
def endpoint(self) -> URL:
'''The configured endpoint URL prefix.'''
return self._endpoint
@property
def user_agent(self) -> str:
'''The configured user agent string.'''
return self._user_agent
@property
def access_key(self) -> str:
'''The configured API access key.'''
return self._access_key
@property
def secret_key(self) -> str:
'''The configured API secret key.'''
return self._secret_key
@property
def version(self) -> str:
'''The configured API protocol version.'''
return self._version
@property
def hash_type(self) -> str:
'''The configured hash algorithm for API authentication signatures.'''
return self._hash_type
@property
def vfolder_mounts(self) -> Tuple[str, ...]:
'''The configured auto-mounted vfolder list.'''
return self._vfolder_mounts
@property
def skip_sslcert_validation(self) -> bool:
'''Whether to skip SSL certificate validation for the API gateway.'''
return self._skip_sslcert_validation
[docs]def get_config():
'''
Returns the configuration for the current process.
If there is no explicitly set :class:`APIConfig` instance,
it will generate a new one from the current environment variables
and defaults.
'''
global _config
if _config is None:
_config = APIConfig()
return _config
[docs]def set_config(conf: APIConfig):
'''
Sets the configuration used throughout the current process.
'''
global _config
_config = conf