Improve settings by using pydantic

CHANGELOG.md

@@ -6,6 +6,10 @@ The format is based on the [KeepAChangeLog] project.
 [KeepAChangeLog]: https://keepachangelog.com/
 
 ## Unreleased
+### Changed
+- [#847] Using pydantic for settings instead of custom class
+
+[#847]: https://github.com/CZ-NIC/pyoidc/pull/847
 
 ## 1.5.0 [2022-12-14]
 

doc/conf.py

@@ -1,12 +1,19 @@
 import alabaster
+import os
+import sys
+
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..', 'src')))
 
 extensions = [
     'sphinx.ext.autodoc',
     'sphinx.ext.napoleon',
+    'sphinxcontrib.autodoc_pydantic',
 ]
 
 autoclass_content = 'both'  # Merge the __init__ docstring into the class docstring.
 autodoc_member_order = 'bysource'  # Order by source ordering
+autodoc_pydantic_model_show_config = True
+autodoc_pydantic_settings_show_json = False
 
 templates_path = ['_templates']
 

setup.py

@@ -78,7 +78,7 @@ def run_tests(self):
     extras_require={
         'develop': ["cherrypy==3.2.4", "pyOpenSSL"],
         'testing': tests_requires,
-        'docs': ['Sphinx', 'sphinx-autobuild', 'alabaster'],
+        'docs': ['Sphinx', 'sphinx-autobuild', 'alabaster', 'autodoc_pydantic'],
         'quality': ['pylama', 'isort', 'eradicate', 'mypy', 'black', 'bandit', 'readme_renderer[md]'],
         'types': ['types-requests'],
         'ldap_authn': ['python-ldap'],
@@ -87,6 +87,7 @@ def run_tests(self):
     install_requires=[
         "requests",
         "pycryptodomex",
+        "pydantic",
         "pyjwkest>=1.3.6",
         "mako",
         "cryptography",

src/oic/utils/settings.py

@@ -8,97 +8,48 @@
 
 In order to configure some objects in PyOIDC, you need a settings object.
 If you need to add some settings, make sure that you settings class inherits from the appropriate class in this module.
+
+The settings make use of `pydantic <https://docs.pydantic.dev/usage/settings/>`_ library.
+It is possible to instance them directly or use environment values to fill the settings.
 """
-import typing
 from typing import Optional
 from typing import Tuple
 from typing import Union
 
 import requests
+from pydantic import BaseSettings
 
 
-class SettingsException(Exception):
-    """Exception raised by misconfigured settings class."""
-
+class PyoidcSettings(BaseSettings):
+    """Main class for all settings shared among consumer and client."""
 
-class PyoidcSettings:
+    verify_ssl: Union[bool, str] = True
     """
-    Main class for all settings shared among consumer and client.
-
-    Keyword Args:
-        verify_ssl
-            Control TLS server certificate validation.
-            If set to True the certificate is validated against the global settings,
-            if set to False, no validation is performed.
-            If set to a filename this is used as a certificate bundle in openssl format.
-            If set to a directory name this is used as a CA directory in the openssl format.
-        client_cert
-            Local cert to use as client side certificate.
-            Can be a single file (containing the private key and the certificate) or a tuple of both file's path.
-        timeout
-            Timeout for requests library.
-            Can be specified either as a single float or as a tuple of floats.
-            For more details, refer to ``requests`` documentation.
+    Control TLS server certificate validation:
 
+    * If set to True the certificate is validated against the global settings,
+    * If set to False, no validation is performed.
+    * If set to a filename this is used as a certificate bundle in openssl format.
+    * If set to a directory name this is used as a CA directory in the openssl format.
     """
-
-    def __init__(
-        self,
-        verify_ssl: Union[bool, str] = True,
-        client_cert: Union[None, str, Tuple[str, str]] = None,
-        timeout: Union[float, Tuple[float, float]] = 5,
-    ):
-        self.verify_ssl = verify_ssl
-        self.client_cert = client_cert
-        self.timeout = timeout
-
-    def __setattr__(self, name, value):
-        """This attempts to check if value matches the expected value."""
-        annotation = typing.get_type_hints(self.__init__)[name]  # type: ignore
-        # Expand Union -> Since 3.8, this can be written as typing.get_origin
-        if getattr(annotation, "__origin__", annotation) is Union:
-            expanded = tuple(an for an in annotation.__args__)
-        else:
-            expanded = (annotation,)
-        # Convert Generics
-        # FIXME: this doesn't check the args of the generic
-        resolved = tuple(getattr(an, "__origin__", an) for an in expanded)
-        # Add int if float is present
-        if float in resolved:
-            resolved = resolved + (int,)
-        # FIXME: Add more valid substitution
-        if isinstance(value, resolved):
-            # FIXME: Handle bool being an instance of int...
-            super().__setattr__(name, value)
-        else:
-            raise SettingsException(
-                "%s has a type of %s, expected any of %s."
-                % (name, type(value), resolved),
-            )
-
-
-class ClientSettings(PyoidcSettings):
+    client_cert: Union[None, str, Tuple[str, str]] = None
+    """
+    Local cert to use as client side certificate.
+    Can be a single file (containing the private key and the certificate) or a tuple of both file's path.
+    """
+    timeout: Union[float, Tuple[float, float]] = 5
+    """
+    Timeout for requests library.
+    Can be specified either as a single float or as a tuple of floats.
+    For more details, refer to ``requests`` documentation.
     """
-    Base settings for consumer shared among OAuth 2.0 and OpenID Connect.
 
-    Keyword Args:
-        requests_session
-            Instance of `requests.Session` with configuration options.
 
-    """
+class ClientSettings(PyoidcSettings):
+    """Base settings for consumer shared among OAuth 2.0 and OpenID Connect."""
 
-    def __init__(
-        self,
-        verify_ssl: Union[bool, str] = True,
-        client_cert: Union[None, str, Tuple[str, str]] = None,
-        timeout: Union[float, Tuple[float, float]] = 5,
-        requests_session: Optional[requests.Session] = None,
-    ):
-        super().__init__(
-            verify_ssl=verify_ssl, client_cert=client_cert, timeout=timeout
-        )
-        # For session persistence
-        self.requests_session = requests_session
+    requests_session: Optional[requests.Session] = None
+    """Instance of `requests.Session` with configuration options."""
 
 
 class OauthClientSettings(ClientSettings):
@@ -131,6 +82,3 @@ class OauthProviderSettings(OauthServerSettings):
 
 class OicProviderSettings(OicServerSettings):
     """Specific settings for OpenID Connect provider."""
-
-    # TODO: Decide on inheritance...
-    # It might be better to have a mixin providing OIC specific stuff?