From bfc669cd116dc38cdea37edb597c96a864b57db1 Mon Sep 17 00:00:00 2001
From: Adrien <me@adrien.run>
Date: Sat, 9 Sep 2023 23:34:04 +0200
Subject: [PATCH] =?UTF-8?q?=E2=99=BB=EF=B8=8F=20Use=20pydantic-settings=20?=
 =?UTF-8?q?to=20handle=20config=20file?=
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---
 backend/backend/settings.py | 75 ++++++++++++++++++++++---------------
 backend/pyproject.toml      |  8 +++-
 2 files changed, 51 insertions(+), 32 deletions(-)

diff --git a/backend/backend/settings.py b/backend/backend/settings.py
index ff6bf84..ab2b75b 100644
--- a/backend/backend/settings.py
+++ b/backend/backend/settings.py
@@ -1,6 +1,14 @@
-from typing import Any
+from __future__ import annotations
 
-from pydantic import BaseModel, BaseSettings, Field, root_validator, SecretStr
+from typing import Annotated
+
+from pydantic import BaseModel, SecretStr
+from pydantic.functional_validators import model_validator
+from pydantic_settings import (
+    BaseSettings,
+    PydanticBaseSettingsSource,
+    SettingsConfigDict,
+)
 
 
 class HttpSettings(BaseModel):
@@ -9,28 +17,13 @@ class HttpSettings(BaseModel):
     cert: str | None = None
 
 
-def check_user_password(cls, values: dict[str, Any]) -> dict[str, Any]:
-    user = values.get("user")
-    password = values.get("password")
-
-    if user is not None and password is None:
-        raise ValueError("user is set, password shall be set too.")
-
-    if password is not None and user is None:
-        raise ValueError("password is set, user shall be set too.")
-
-    return values
-
-
 class DatabaseSettings(BaseModel):
-    name: str = "carrramba-encore-rate"
-    host: str = "127.0.0.1"
-    port: int = 5432
+    name: str
+    host: str
+    port: int
     driver: str = "postgresql+psycopg"
-    user: str | None = None
-    password: SecretStr | None = None
-
-    _user_password_validation = root_validator(allow_reuse=True)(check_user_password)
+    user: str
+    password: Annotated[SecretStr, check_user_password]
 
 
 class CacheSettings(BaseModel):
@@ -38,9 +31,18 @@ class CacheSettings(BaseModel):
     host: str = "127.0.0.1"
     port: int = 6379
     user: str | None = None
-    password: SecretStr | None = None
+    password: Annotated[SecretStr | None, check_user_password] = None
 
-    _user_password_validation = root_validator(allow_reuse=True)(check_user_password)
+
+@model_validator(mode="after")
+def check_user_password(self) -> DatabaseSettings | CacheSettings:
+    if self.user is not None and self.password is None:
+        raise ValueError("user is set, password shall be set too.")
+
+    if self.password is not None and self.user is None:
+        raise ValueError("password is set, user shall be set too.")
+
+    return self
 
 
 class TracingSettings(BaseModel):
@@ -50,10 +52,23 @@ class TracingSettings(BaseModel):
 class Settings(BaseSettings):
     app_name: str
 
-    idfm_api_key: SecretStr = Field(..., env="IDFM_API_KEY")
-    clear_static_data: bool = Field(False, env="CLEAR_STATIC_DATA")
+    idfm_api_key: SecretStr
+    clear_static_data: bool
 
-    http: HttpSettings = HttpSettings()
-    db: DatabaseSettings = DatabaseSettings()
-    cache: CacheSettings = CacheSettings()
-    tracing: TracingSettings = TracingSettings()
+    http: HttpSettings
+    db: DatabaseSettings
+    cache: CacheSettings
+    tracing: TracingSettings
+
+    model_config = SettingsConfigDict(env_prefix="CER__", env_nested_delimiter="__")
+
+    @classmethod
+    def settings_customise_sources(
+        cls,
+        settings_cls: type[BaseSettings],
+        init_settings: PydanticBaseSettingsSource,
+        env_settings: PydanticBaseSettingsSource,
+        dotenv_settings: PydanticBaseSettingsSource,
+        file_secret_settings: PydanticBaseSettingsSource,
+    ) -> tuple[PydanticBaseSettingsSource, ...]:
+        return env_settings, init_settings, file_secret_settings
diff --git a/backend/pyproject.toml b/backend/pyproject.toml
index 8af85e7..0156387 100644
--- a/backend/pyproject.toml
+++ b/backend/pyproject.toml
@@ -9,7 +9,7 @@ readme = "README.md"
 python = "^3.11"
 aiohttp = "^3.8.3"
 aiofiles = "^22.1.0"
-fastapi = "^0.95.0"
+fastapi = "^0.103.0"
 uvicorn = "^0.20.0"
 msgspec = "^0.12.0"
 opentelemetry-instrumentation-fastapi = "^0.38b0"
@@ -23,11 +23,12 @@ sqlalchemy = "^2.0.12"
 psycopg = "^3.1.9"
 pyyaml = "^6.0"
 fastapi-cache2 = {extras = ["redis"], version = "^0.2.1"}
+pydantic-settings = "^2.0.3"
 
 [tool.poetry.group.db_updater.dependencies]
 aiofiles = "^22.1.0"
 aiohttp = "^3.8.3"
-fastapi = "^0.95.0"
+fastapi = "^0.103.0"
 msgspec = "^0.12.0"
 opentelemetry-instrumentation-fastapi = "^0.38b0"
 opentelemetry-instrumentation-sqlalchemy = "^0.38b0"
@@ -41,11 +42,14 @@ pyyaml = "^6.0"
 sqlalchemy = "^2.0.12"
 sqlalchemy-utils = "^0.41.1"
 tqdm = "^4.65.0"
+pydantic-settings = "^2.0.3"
 
 [build-system]
 requires = ["poetry-core"]
 build-backend = "poetry.core.masonry.api"
 
+
+
 [tool.poetry.group.dev.dependencies]
 pylsp-mypy = "^0.6.2"
 mccabe = "^0.7.0"